Science.gov

Sample records for reduce carbon emissions

  1. Environment, Renewable Energy and Reduced Carbon Emissions

    NASA Technical Reports Server (NTRS)

    Sen, S.; Khazanov, G.; Kishimoto, Y.

    2011-01-01

    Increased energy security and reduced carbon emissions pose significant challenges for science and technology. However, they also create substantial opportunities for innovative research and development. In this review paper, we highlight some of the key opportunities and mention public policies that are needed to enable the efforts and to maximize the probability of their success. Climate is among the uttermost nonlinear behaviors found around us. As recent studies showed the possible effect of cosmic rays on the Earth's climate, we investigate how complex interactions between the planet and its environment can be responsible for climate anomalies.

  2. Reduced environmental emissions and carbon sequestration

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Agricultural ecosystems can play a significant role in the production and consumption of greenhouse gases, specifically, carbon dioxide. Information is needed on the mechanism and magnitude of gas generation and emission from agricultural soils with specific emphasis on tillage mechanisms. The objec...

  3. Options for reducing carbon dioxide emissions

    SciTech Connect

    Rosenfeld, A.H.; Price, L.

    1991-08-01

    Improvements in energy efficiency can significantly reduce the annual growth in greenhouse gas emissions. Such improvements occur when energy intensity is reduced; no reduction in energy services is required. Using the concept of cost of conserved energy'' to develop conservation supply curves similar to resource supply curves, researchers consistently find that electricity and natural gas savings of nearly 50% of current consumption are possible for US buildings. Such reductions in energy consumption directly reduce emissions of greenhouse gases. To capture these savings, we must continue to develop energy-efficient technologies and strategies. This paper describes three recent energy-efficient technologies that benefited from energy conservation research and development (R D) funding: high-frequency ballasts, compact fluorescent lamps, and low-emissivity windows. Other advanced technologies and strategies of spectrally selective windows, superwindows, electrochromic windows, advanced insulation, low-flow showerheads, improved recessed lamp fixtures, whitening surfaces and planting urban trees, daylighting, and thermal energy storage are also discussed. 33 refs., 9 figs., 3 tabs.

  4. Reducing Carbon Dioxide Emissions: Using the Mole Concept.

    ERIC Educational Resources Information Center

    Myers, Alan

    2002-01-01

    Provides an application of quantitative chemistry concepts in the context of motor vehicle emissions. Shows how carbon dioxide emissions from cars may be reduced by up to 25% by reducing motorway speeds from 70-75 mph to 60 mph. (Author/MM)

  5. Can reducing black carbon emissions counteract global warming?

    SciTech Connect

    Tami C. Bond; Haolin Sun

    2005-08-15

    Field measurements and model results have recently shown that aerosols may have important climatic impacts. One line of inquiry has investigated whether reducing climate-warming soot or black carbon aerosol emissions can form a viable component of mitigating global warming. Black carbon is produced by poor combustion, from our example hard coal cooking fires for and industrial pulverized coal boilers. The authors review and acknowledge scientific arguments against considering aerosols and greenhouse gases in a common framework, including the differences in the physical mechanisms of climate change and relevant time scales. It is argued that such a joint consideration is consistent with the language of the United Nations Framework Convention on Climate Change. Results from published climate-modeling studies are synthesized to obtain a global warming potential for black carbon relative to that of CO{sub 2} (680 on a 100 year basis). This calculation enables a discussion of cost-effectiveness for mitigating the largest sources of black carbon. It is found that many emission reductions are either expensive or difficult to enact when compared with greenhouse gases, particularly in Annex I countries. Finally, a role for black carbon in climate mitigation strategies is proposed that is consistent with the apparently conflicting arguments raised during the discussion. Addressing these emissions is a promising way to reduce climatic interference primarily for nations that have not yet agreed to address greenhouse gas emissions and provides the potential for a parallel climate agreement. 31 refs., 3 figs., 1 tab.

  6. In Brief: Reducing black carbon emissions could immediately reduce global temperature increases

    NASA Astrophysics Data System (ADS)

    Tretkoff, Ernie

    2011-03-01

    A new assessment by the United Nations Environment Programme (UNEP) shows that measures to reduce emissions of black carbon, or soot, which is produced through burning of wood and other biofuels as well as by some industrial processes, could improve public health and help to significantly reduce projected global temperature increases. The Integrated Assessment of Black Carbon and Tropospheric Ozone highlights how specific measures targeting black carbon and other emissions from fossil fuel extraction, residential wood-burning cooking, diesel vehicles, waste management, agriculture, and small industries could affect climate. Full implementation of a variety of measures to reduce black carbon and methane emissions could reduce future global warming by about 0.5°C, the assessment found. Reducing black carbon could have substantial benefits in the Arctic, the Himalayas, and other snow-covered regions because black carbon that settles on top of snow absorbs heat, speeding melting of snow and ice. Black carbon emission reductions would affect global temperatures more quickly than carbon dioxide emission reductions. Furthermore, reducing black carbon emissions would improve public health in the regions that emit large amounts of the harmful air pollutant.

  7. Exercise based transportation reduces oil consumption and carbon emissions

    NASA Astrophysics Data System (ADS)

    Higgins, P. A.

    2004-12-01

    Current abuse and misrepresentation of science hinders society's ability to address climate change. Scientific abuse results, in part, from a widespread perception that curbing emissions will require substantial economic, political, or personal sacrifice. Here I provide one example to illustrate that this perception is false. Simply walking or biking the amount recommended for a healthy lifestyle could reduce carbon emissions up to 11 percent if the distances traveled were substituted for car travel. This level of exercise is also sufficient to eliminate obese and overweight conditions in a few years without draconian diet plans. A reduction in carbon dioxide emissions of roughly 35 percent is possible if the revenue saved through decreased health care spending on obesity is redirected toward carbon abatement. This emissions reduction far exceeds that required by the Kyoto Protocol at no net cost. Finally, widespread substitution of driving with distances traveled during recommended daily exercise would considerably ease societal dependence on oil, which leads not only to climate change but also to air pollution, political and economic instability and habitat degradation. Thus, exercise based transportation constitutes a potentially favorable alternative to the energy and diet plans that are currently under consideration and a substantial step toward dealing with the threat of climate change.

  8. Forest management strategies for reducing carbon emissions, the French case

    NASA Astrophysics Data System (ADS)

    Valade, Aude; Luyssaert, Sebastiaan; Bellassen, Valentin; Vallet, Patrick; Martin, Manuel

    2015-04-01

    International agreements now recognize the role of forest in the mitigation of climate change through the levers of in-situ sequestration, storage in products and energy and product substitution. These three strategies of carbon management are often antagonistic and it is still not clear which strategy would have the most significant impact on atmospheric carbon concentrations. With a focus on France, this study compares several scenarios of forest management in terms of their effect on the overall carbon budget from trees to wood-products. We elaborated four scenarios of forest management that target different wood production objectives. One scenario is 'Business as usual' and reproduces the current forest management and wood production levels. Two scenarios target an increase in bioenergy wood production, with either long-term or short-term goals. One scenario aims at increasing the production of timber for construction. For this, an empirical regression model was developed building on the rich French inventory database. The model can project the current forest resource at a time horizon of 20 years for characteristic variables diameter, standing volume, above-ground biomass, stand age. A simplified life-cycle analysis provides a full carbon budget for each scenario from forest management to wood use and allows the identification of the scenario that most reduces carbon emissions.

  9. Global cost estimates of reducing carbon emissions through avoided deforestation

    PubMed Central

    Kindermann, Georg; Obersteiner, Michael; Sohngen, Brent; Sathaye, Jayant; Andrasko, Kenneth; Rametsteiner, Ewald; Schlamadinger, Bernhard; Wunder, Sven; Beach, Robert

    2008-01-01

    Tropical deforestation is estimated to cause about one-quarter of anthropogenic carbon emissions, loss of biodiversity, and other environmental services. United Nations Framework Convention for Climate Change talks are now considering mechanisms for avoiding deforestation (AD), but the economic potential of AD has yet to be addressed. We use three economic models of global land use and management to analyze the potential contribution of AD activities to reduced greenhouse gas emissions. AD activities are found to be a competitive, low-cost abatement option. A program providing a 10% reduction in deforestation from 2005 to 2030 could provide 0.3–0.6 Gt (1 Gt = 1 × 105 g) CO2·yr−1 in emission reductions and would require $0.4 billion to $1.7 billion·yr−1 for 30 years. A 50% reduction in deforestation from 2005 to 2030 could provide 1.5–2.7 Gt CO2·yr−1 in emission reductions and would require $17.2 billion to $28.0 billion·yr−1. Finally, some caveats to the analysis that could increase costs of AD programs are described. PMID:18650377

  10. Institute a modest carbon tax to reduce carbon emissions, finance clean energy technology development, cut taxes, and reduce the deficit

    SciTech Connect

    Muro, Mark; Rothwell, Jonathan

    2012-11-15

    The nation should institute a modest carbon tax in order to help clean up the economy and stabilize the nation’s finances. Specifically, Congress and the president should implement a $20 per ton, steadily increasing carbon excise fee that would discourage carbon dioxide emissions while shifting taxation onto pollution, financing energy efficiency (EE) and clean technology development, and providing opportunities to cut taxes or reduce the deficit. The net effect of these policies would be to curb harmful carbon emissions, improve the nation’s balance sheet, and stimulate job-creation and economic renewal.

  11. Carbon Footprint of Telemedicine Solutions - Unexplored Opportunity for Reducing Carbon Emissions in the Health Sector

    PubMed Central

    Holmner, Åsa; Ebi, Kristie L.; Lazuardi, Lutfan; Nilsson, Maria

    2014-01-01

    Background The healthcare sector is a significant contributor to global carbon emissions, in part due to extensive travelling by patients and health workers. Objectives To evaluate the potential of telemedicine services based on videoconferencing technology to reduce travelling and thus carbon emissions in the healthcare sector. Methods A life cycle inventory was performed to evaluate the carbon reduction potential of telemedicine activities beyond a reduction in travel related emissions. The study included two rehabilitation units at Umeå University Hospital in Sweden. Carbon emissions generated during telemedicine appointments were compared with care-as-usual scenarios. Upper and lower bound emissions scenarios were created based on different teleconferencing solutions and thresholds for when telemedicine becomes favorable were estimated. Sensitivity analyses were performed to pinpoint the most important contributors to emissions for different set-ups and use cases. Results Replacing physical visits with telemedicine appointments resulted in a significant 40–70 times decrease in carbon emissions. Factors such as meeting duration, bandwidth and use rates influence emissions to various extents. According to the lower bound scenario, telemedicine becomes a greener choice at a distance of a few kilometers when the alternative is transport by car. Conclusions Telemedicine is a potent carbon reduction strategy in the health sector. But to contribute significantly to climate change mitigation, a paradigm shift might be required where telemedicine is regarded as an essential component of ordinary health care activities and not only considered to be a service to the few who lack access to care due to geography, isolation or other constraints. PMID:25188322

  12. Challenges for Reducing Emissions of Black Carbon from the Transport Sector in Urban Areas

    NASA Astrophysics Data System (ADS)

    Zavala, M. A.; Molina, L. T.

    2013-05-01

    The transport sector is a large contributor of harmful gaseous and particulate emissions in many urban areas. Black carbon is a component of short-lived particulate matter emitted predominantly by freight, public transport, and heavy- duty trucks. Controlling the emissions of black carbon from the transport sector is important for mitigating its impacts on climate, ecosystems, and human health. However, reducing the emissions of black carbon from mobile sources may be a challenging task in many developing urban areas due to economic, social, and technical constrains. Several emissions control technologies offer a proven approach for reducing emissions of black carbon from diesel-powered mobile sources, but the accurate quantification of associated emissions benefits in developing urban areas is not well documented. We describe recent advances for the estimation of black carbon emissions from the transport sector in real world driving conditions and present examples of the potential benefits of implementing various emission control technologies in Mexico. The results can help in the identification of key factors that hinder the implementation of control emissions for reducing emissions of black carbon elsewhere.

  13. An optimal control model for reducing and trading of carbon emissions

    NASA Astrophysics Data System (ADS)

    Guo, Huaying; Liang, Jin

    2016-03-01

    A stochastic optimal control model of reducing and trading for carbon emissions is established in this paper. With considerations of reducing the carbon emission growth and the price of the allowances in the market, an optimal policy is searched to have the minimum total costs to achieve the agreement of emission reduction targets. The model turns to a two-dimension HJB equation problem. By the methods of reducing dimension and Cole-Hopf transformation, a semi-closed form solution of the corresponding HJB problem under some assumptions is obtained. For more general cases, the numerical calculations, analysis and comparisons are presented.

  14. Arctic Black Carbon Initiative: Reducing Emissions of Black Carbon from Power & Industry in Russia

    NASA Astrophysics Data System (ADS)

    Cresko, J.; Hodson, E. L.; Cheng, M.; Fu, J. S.; Huang, K.; Storey, J.

    2012-12-01

    Deposition of black carbon (BC) on snow and ice is widely considered to have a climate warming effect by reducing the surface albedo and promoting snowmelt. Such positive climate feedbacks in the Arctic are especially problematic because rising surface temperatures may trigger the release of large Arctic stores of terrestrial carbon, further amplifying current warming trends. Recognizing the Arctic as a vulnerable region, the U.S. government committed funds in Copenhagen in 2009 for international cooperation targeting Arctic BC emissions reductions. As a result, the U.S. Department of State has funded three research and demonstration projects with the goal to better understand and mitigate BC deposition in the Russian Arctic from a range of sources. The U.S. Department of Energy's (DOE) Arctic BC initiative presented here is focused on mitigating BC emissions resulting from heat and power generation as well as industrial applications. A detailed understanding of BC sources and its transport and fate is required to prioritize efforts to reduce BC emissions from sources that deposit in the Russian Arctic. Sources of BC include the combustion of fossil fuels (e.g. coal, fuel oil, diesel) and the combustion of biomass (e.g. wildfires, agricultural burning, residential heating and cooking). Information on fuel use and associated emissions from the industrial and heat & power sectors in Russia is scarce and difficult to obtain from the open literature. Hence, our project includes a research component designed to locate Arctic BC emissions sources in Russia and determine associated BC transport patterns. We use results from the research phase to inform a subsequent assessment/demonstration phase. We use a back-trajectory modeling method (potential source contribution function - PSCF), which combines multi-year, high-frequency measurements with knowledge about atmospheric transport patterns. The PSCF modeling allows us to map the probability (by season and year) at course

  15. A SECOND-BEST EVALUATION OF EIGHT POLICY INSTRUMENTS TO REDUCE CARBON EMISSIONS. (R825313)

    EPA Science Inventory

    Abstract

    This paper uses a numerical general equilibrium model to compare the costs of alternative policies for reducing carbon emissions in a second-best setting with a distortionary tax on labor. We examine a carbon tax, two energy taxes, and both narrow-based and br...

  16. Potential biodiversity benefits from international programs to reduce carbon emissions from deforestation.

    PubMed

    Siikamäki, Juha; Newbold, Stephen C

    2012-01-01

    Deforestation is the second largest anthropogenic source of carbon dioxide emissions and options for its reduction are integral to climate policy. In addition to providing potentially low cost and near-term options for reducing global carbon emissions, reducing deforestation also could support biodiversity conservation. However, current understanding of the potential benefits to biodiversity from forest carbon offset programs is limited. We compile spatial data on global forest carbon, biodiversity, deforestation rates, and the opportunity cost of land to examine biodiversity conservation benefits from an international program to reduce carbon emissions from deforestation. Our results indicate limited geographic overlap between the least-cost areas for retaining forest carbon and protecting biodiversity. Therefore, carbon-focused policies will likely generate substantially lower benefits to biodiversity than a more biodiversity-focused policy could achieve. These results highlight the need to systematically consider co-benefits, such as biodiversity in the design and implementation of forest conservation programs to support international climate policy. PMID:22307280

  17. Global economic potential for reducing carbon dioxide emissions from mangrove loss

    PubMed Central

    Siikamäki, Juha; Sanchirico, James N.; Jardine, Sunny L.

    2012-01-01

    Mangroves are among the most threatened and rapidly disappearing natural environments worldwide. In addition to supporting a wide range of other ecological and economic functions, mangroves store considerable carbon. Here, we consider the global economic potential for protecting mangroves based exclusively on their carbon. We develop unique high-resolution global estimates (5′ grid, about 9 × 9 km) of the projected carbon emissions from mangrove loss and the cost of avoiding the emissions. Using these spatial estimates, we derive global and regional supply curves (marginal cost curves) for avoided emissions. Under a broad range of assumptions, we find that the majority of potential emissions from mangroves could be avoided at less than $10 per ton of CO2. Given the recent range of market price for carbon offsets and the cost of reducing emissions from other sources, this finding suggests that protecting mangroves for their carbon is an economically viable proposition. Political-economy considerations related to the ability of doing business in developing countries, however, can severely limit the supply of offsets and increases their price per ton. We also find that although a carbon-focused conservation strategy does not automatically target areas most valuable for biodiversity, implementing a biodiversity-focused strategy would only slightly increase the costs. PMID:22847435

  18. Global economic potential for reducing carbon dioxide emissions from mangrove loss.

    PubMed

    Siikamäki, Juha; Sanchirico, James N; Jardine, Sunny L

    2012-09-01

    Mangroves are among the most threatened and rapidly disappearing natural environments worldwide. In addition to supporting a wide range of other ecological and economic functions, mangroves store considerable carbon. Here, we consider the global economic potential for protecting mangroves based exclusively on their carbon. We develop unique high-resolution global estimates (5' grid, about 9 × 9 km) of the projected carbon emissions from mangrove loss and the cost of avoiding the emissions. Using these spatial estimates, we derive global and regional supply curves (marginal cost curves) for avoided emissions. Under a broad range of assumptions, we find that the majority of potential emissions from mangroves could be avoided at less than $10 per ton of CO(2). Given the recent range of market price for carbon offsets and the cost of reducing emissions from other sources, this finding suggests that protecting mangroves for their carbon is an economically viable proposition. Political-economy considerations related to the ability of doing business in developing countries, however, can severely limit the supply of offsets and increases their price per ton. We also find that although a carbon-focused conservation strategy does not automatically target areas most valuable for biodiversity, implementing a biodiversity-focused strategy would only slightly increase the costs. PMID:22847435

  19. Building capacity for national carbon measurements for reducing emissions from deforestation and forest degradation

    NASA Astrophysics Data System (ADS)

    Goetz, S. J.; Laporte, N.; Horning, N.; Pelletier, J.; Jantz, P.; Ndunda, P.

    2014-12-01

    Many tropical countries are now working on developing their strategies for reducing emissions from deforestation and forest degradation, including activities that result in conservation or enhancement of forest carbon stocks and sustainable management of forests to effectively decrease atmospheric carbon emissions (i.e. REDD+). A new international REDD+ agreement is at the heart of recent negotiations of the parties to the UN Framework Convention on Climate Change (UNFCCC). REDD+ mechanisms could provide an opportunity to not only diminish an important source of emissions, but also to promote large-scale conservation of tropical forests and establish incentives and opportunities to alleviate poverty. Most tropical countries still lack basic information for developing and implementing their forest carbon stock assessments, including the extent of forest area and the rate at which forests are being cleared and/or degraded, and the carbon amounts associated with these losses. These same countries also need support to conduct integrated assessments of the most promising approaches for reducing emissions, and in identifying those policy options that hold the greatest potential while minimizing potential negative impacts of REDD+ policies. The WHRC SERVIR project in East Africa is helping to provide these data sets to countries via best practice tools and methods to support cost effective forest carbon monitoring solutions and more informed decision making processes under REDD+. We will present the results of our capacity building activites in the region and planned future efforts being coordinated with the NASA-SERVIR Hub in Kenya to support to REDD+ decision support.

  20. Economic implications of reducing carbon emissions from energy use and industrial processes in Brazil.

    PubMed

    Chen, Y-H Henry; Timilsina, Govinda R; Landis, Florian

    2013-11-30

    This study assesses the economy-wide impacts of cutting CO2 emissions on the Brazilian economy. It finds that in 2040, the business-as-usual CO2 emissions from energy use and industrial processes would be almost three times as high as those in 2010 and would account for more than half of total national CO2 emissions. The current policy aims to reduce deforestation by 70 percent by 2017 and lower emissions intensity of the overall economy by 36-39 percent by 2020. If the policy were implemented as planned and continued to 2040, there would be no need to cut CO2 emissions from energy use and industrial processes until 2035, as emissions reduction through controlling deforestation would be enough to meet the voluntary carbon mitigation target of Brazil. The study also finds that using the carbon tax revenue to subsidize wind power can effectively increase the country's wind power output if that is the policy priority. Further, it finds evidence supporting the double dividend hypothesis, i.e., using revenue from a hypothetical carbon tax to finance a cut in labor income tax can significantly lower the GDP impacts of the carbon tax. PMID:24184985

  1. Incorporation of catalytic dehydrogenation into fischer-tropsch synthesis to significantly reduce carbon dioxide emissions

    DOEpatents

    Huffman, Gerald P.

    2012-11-13

    A new method of producing liquid transportation fuels from coal and other hydrocarbons that significantly reduces carbon dioxide emissions by combining Fischer-Tropsch synthesis with catalytic dehydrogenation is claimed. Catalytic dehydrogenation (CDH) of the gaseous products (C1-C4) of Fischer-Tropsch synthesis (FTS) can produce large quantities of hydrogen while converting the carbon to multi-walled carbon nanotubes (MWCNT). Incorporation of CDH into a FTS-CDH plant converting coal to liquid fuels can eliminate all or most of the CO.sub.2 emissions from the water-gas shift (WGS) reaction that is currently used to elevate the H.sub.2 level of coal-derived syngas for FTS. Additionally, the FTS-CDH process saves large amounts of water used by the WGS reaction and produces a valuable by-product, MWCNT.

  2. A warmer policy for a colder climate: Can China both reduce poverty and cap carbon emissions?

    PubMed

    Glomsrød, Solveig; Wei, Taoyuan; Aamaas, Borgar; Lund, Marianne T; Samset, Bjørn H

    2016-10-15

    Reducing global carbon dioxide (CO2) emissions is often thought to be at odds with economic growth and poverty reduction. Using an integrated assessment modeling approach, we find that China can cap CO2 emissions at 2015 level while sustaining economic growth and reducing the urban-rural income gap by a third by 2030. As a result, the Chinese economy becomes less dependent on exports and investments, as household consumption emerges as a driver behind economic growth, in line with current policy priorities. The resulting accumulated greenhouse gas emissions reduction 2016-2030 is about 60billionton (60Mg) CO2e. A CO2 tax combined with income re-distribution initially leads to a modest warming due to reduction in sulfur dioxide (SO2) emissions. However, the net effect is eventually cooling when the effect of reduced CO2 emissions dominates due to the long-lasting climate response of CO2. The net reduction in global temperature for the remaining part of this century is about 0.03±0.02°C, corresponding in magnitude to the cooling from avoiding one year of global CO2 emissions. PMID:27295595

  3. Reduced carbon emission estimates from fossil fuel combustion and cement production in China

    SciTech Connect

    Liu, Z.; Guan, D.; Wei, W.; Davis, S.; Ciais, P.; Bai, J; Peng, S.; Zhang, Q.; Hubacek, K.; Marland, Gregg; Andres, Robert Joseph; Crawford-Brown, D.; Lin, J.; Zhao, H.; Hong, C.; Boden, Thomas A.; Feng, K.; Peters, Glen P.; Xi, F.; Liu, J.; Li, Y.; Zhao, Y.; Zeng, Ning; He, K.

    2015-08-19

    Nearly three-quarters of the growth in global carbon emissions from the burning of fossil fuels and cement production between 2010 and 2012 occurred in China. Yet estimates of Chinese emissions remain subject to large uncertainty; inventories of China’s total fossil fuel carbon emissions in 2008 differ by 0.3 gigatonnes of carbon, or 15 per cent. The primary sources of this uncertainty are conflicting estimates of energy consumption and emission factors, the latter being uncertain because of very few actual measurements representative of the mix of Chinese fuels. Here we re-evaluate China’s carbon emissions using updated and harmonized energy consumption and clinker production data and two new and comprehensive sets of measured emission factors for Chinese coal. We find that total energy consumption in China was 10 per cent higher in 2000–2012 than the value reported by China’s national statistics, that emission factors for Chinese coal are on average 40 per cent lower than the default values recommended by the Intergovernmental Panel on Climate Change, and that emissions from China’s cement production are 45 per cent less than recent estimates. Altogether, our revised estimate of China’s CO2 emissions from fossil fuel combustion and cement production is 2.49 gigatonnes of carbon (2 standard deviations = ±7.3 per cent) in 2013, which is 14 per cent lower than the emissions reported by other prominent inventories. Over the full period 2000 to 2013, our revised estimates are 2.9 gigatonnes of carbon less than previous estimates of China’s cumulative carbon emissions. Our findings suggest that overestimation of China’s emissions in 2000–2013 may be larger than China’s estimated total forest sink in 1990–2007 (2.66 gigatonnes of carbon) or China’s land carbon sink in 2000–2009 (2.6 gigatonnes of carbon).

  4. Reduced carbon emission estimates from fossil fuel combustion and cement production in China.

    PubMed

    Liu, Zhu; Guan, Dabo; Wei, Wei; Davis, Steven J; Ciais, Philippe; Bai, Jin; Peng, Shushi; Zhang, Qiang; Hubacek, Klaus; Marland, Gregg; Andres, Robert J; Crawford-Brown, Douglas; Lin, Jintai; Zhao, Hongyan; Hong, Chaopeng; Boden, Thomas A; Feng, Kuishuang; Peters, Glen P; Xi, Fengming; Liu, Junguo; Li, Yuan; Zhao, Yu; Zeng, Ning; He, Kebin

    2015-08-20

    Nearly three-quarters of the growth in global carbon emissions from the burning of fossil fuels and cement production between 2010 and 2012 occurred in China. Yet estimates of Chinese emissions remain subject to large uncertainty; inventories of China's total fossil fuel carbon emissions in 2008 differ by 0.3 gigatonnes of carbon, or 15 per cent. The primary sources of this uncertainty are conflicting estimates of energy consumption and emission factors, the latter being uncertain because of very few actual measurements representative of the mix of Chinese fuels. Here we re-evaluate China's carbon emissions using updated and harmonized energy consumption and clinker production data and two new and comprehensive sets of measured emission factors for Chinese coal. We find that total energy consumption in China was 10 per cent higher in 2000-2012 than the value reported by China's national statistics, that emission factors for Chinese coal are on average 40 per cent lower than the default values recommended by the Intergovernmental Panel on Climate Change, and that emissions from China's cement production are 45 per cent less than recent estimates. Altogether, our revised estimate of China's CO2 emissions from fossil fuel combustion and cement production is 2.49 gigatonnes of carbon (2 standard deviations = ±7.3 per cent) in 2013, which is 14 per cent lower than the emissions reported by other prominent inventories. Over the full period 2000 to 2013, our revised estimates are 2.9 gigatonnes of carbon less than previous estimates of China's cumulative carbon emissions. Our findings suggest that overestimation of China's emissions in 2000-2013 may be larger than China's estimated total forest sink in 1990-2007 (2.66 gigatonnes of carbon) or China's land carbon sink in 2000-2009 (2.6 gigatonnes of carbon). PMID:26289204

  5. Reduced carbon emission estimates from fossil fuel combustion and cement production in China

    NASA Astrophysics Data System (ADS)

    Liu, Zhu; Guan, Dabo; Wei, Wei; Davis, Steven J.; Ciais, Philippe; Bai, Jin; Peng, Shushi; Zhang, Qiang; Hubacek, Klaus; Marland, Gregg; Andres, Robert J.; Crawford-Brown, Douglas; Lin, Jintai; Zhao, Hongyan; Hong, Chaopeng; Boden, Thomas A.; Feng, Kuishuang; Peters, Glen P.; Xi, Fengming; Liu, Junguo; Li, Yuan; Zhao, Yu; Zeng, Ning; He, Kebin

    2015-08-01

    Nearly three-quarters of the growth in global carbon emissions from the burning of fossil fuels and cement production between 2010 and 2012 occurred in China. Yet estimates of Chinese emissions remain subject to large uncertainty; inventories of China's total fossil fuel carbon emissions in 2008 differ by 0.3 gigatonnes of carbon, or 15 per cent. The primary sources of this uncertainty are conflicting estimates of energy consumption and emission factors, the latter being uncertain because of very few actual measurements representative of the mix of Chinese fuels. Here we re-evaluate China's carbon emissions using updated and harmonized energy consumption and clinker production data and two new and comprehensive sets of measured emission factors for Chinese coal. We find that total energy consumption in China was 10 per cent higher in 2000-2012 than the value reported by China's national statistics, that emission factors for Chinese coal are on average 40 per cent lower than the default values recommended by the Intergovernmental Panel on Climate Change, and that emissions from China's cement production are 45 per cent less than recent estimates. Altogether, our revised estimate of China's CO2 emissions from fossil fuel combustion and cement production is 2.49 gigatonnes of carbon (2 standard deviations = +/-7.3 per cent) in 2013, which is 14 per cent lower than the emissions reported by other prominent inventories. Over the full period 2000 to 2013, our revised estimates are 2.9 gigatonnes of carbon less than previous estimates of China's cumulative carbon emissions. Our findings suggest that overestimation of China's emissions in 2000-2013 may be larger than China's estimated total forest sink in 1990-2007 (2.66 gigatonnes of carbon) or China's land carbon sink in 2000-2009 (2.6 gigatonnes of carbon).

  6. Reduced carbon emission estimates from fossil fuel combustion and cement production in China

    DOE PAGESBeta

    Liu, Z.; Guan, D.; Wei, W.; Davis, S.; Ciais, P.; Bai, J; Peng, S.; Zhang, Q.; Hubacek, K.; Marland, Gregg; et al

    2015-08-19

    Nearly three-quarters of the growth in global carbon emissions from the burning of fossil fuels and cement production between 2010 and 2012 occurred in China. Yet estimates of Chinese emissions remain subject to large uncertainty; inventories of China’s total fossil fuel carbon emissions in 2008 differ by 0.3 gigatonnes of carbon, or 15 per cent. The primary sources of this uncertainty are conflicting estimates of energy consumption and emission factors, the latter being uncertain because of very few actual measurements representative of the mix of Chinese fuels. Here we re-evaluate China’s carbon emissions using updated and harmonized energy consumption andmore » clinker production data and two new and comprehensive sets of measured emission factors for Chinese coal. We find that total energy consumption in China was 10 per cent higher in 2000–2012 than the value reported by China’s national statistics, that emission factors for Chinese coal are on average 40 per cent lower than the default values recommended by the Intergovernmental Panel on Climate Change, and that emissions from China’s cement production are 45 per cent less than recent estimates. Altogether, our revised estimate of China’s CO2 emissions from fossil fuel combustion and cement production is 2.49 gigatonnes of carbon (2 standard deviations = ±7.3 per cent) in 2013, which is 14 per cent lower than the emissions reported by other prominent inventories. Over the full period 2000 to 2013, our revised estimates are 2.9 gigatonnes of carbon less than previous estimates of China’s cumulative carbon emissions. Our findings suggest that overestimation of China’s emissions in 2000–2013 may be larger than China’s estimated total forest sink in 1990–2007 (2.66 gigatonnes of carbon) or China’s land carbon sink in 2000–2009 (2.6 gigatonnes of carbon).« less

  7. New Hampshire Carbon Challenge: Reducing Residential Energy Use and Greenhouse Gas Emissions

    NASA Astrophysics Data System (ADS)

    Schloss, A. L.; Bartlett, D.; Blaha, D.; Skoglund, C.; Dundorf, J.; Froburg, E.; Pasinella, B.

    2007-12-01

    The New Hampshire Carbon Challenge is an initiative of the Institute for the Study of Earth, Oceans and Space at the University of New Hampshire. Our goal is to educate New Hampshire residents about climate change and also encourage them to reduce their household greenhouse gas emissions by 10,000 pounds. The Northeast region is undergoing climate changes consistent with those expected due to increasing levels of CO2 in the atmosphere, while also contributing to climate change as the world's seventh largest source of CO2 emissions. In the USA, approximately 40 percent of CO2 emissions from fossil fuel combustion come from residential energy consumption for space heating, electricity usage, and transportation. Homeowners typically are not aware that modest energy reductions can result in significant carbon savings. Most campaigns that raise awareness of climate change and residential energy usage disseminate information to consumers through newspaper articles, brochures, websites, or other traditional means of communication. These information-only campaigns have not been very effective in changing residential energy consumption. Bombarded with information in their daily lives, the public has become quite adept at tuning most of it out. When much of the information they receive about climate change is confusing and contradictory, residents have even less incentive to change their behavior. The Challenge is unique in that it couples accurate information about climate change with concrete actions homeowners can take to reduce their carbon emissions. Our strategy is to utilize the tools of Community Based Social Marketing, which has been shown to be effective in changing behavior, and also to leverage existing networks including the NH Department of Environmental Services, UNH Cooperative Extension, faith-based communities, municipal energy committees and Climate Project volunteers, to effectively reach residents throughout the state. The response to our program has

  8. A conceptual framework for the evaluation of cost-effectiveness of projects to reduce GHG emissions and sequester carbon

    SciTech Connect

    Sathaye, J.; Norgaard, R.; Makundi, W.

    1993-07-01

    This paper proposes a conceptual framework for evaluating the cost of projects to reduce atmospheric greenhouse gases (GHGs). The evaluation of cost-effectiveness should account for both the timing of carbon emissions and the damage caused by the atmospheric stock of carbon. We develop a conceptual basis to estimate the cost-effectiveness of projects in terms of the cost of reducing atmospheric carbon (CRAC) and other GHGs. CRAC accounts for the economic discount rate, alternative functional forms of the shadow price, the residence period of carbon in the atmosphere, and the multiple monetary benefits of projects. The last item is of particular importance to the developing countries.

  9. Biofuels from crop residue can reduce soil carbon and increase CO2 emissions

    NASA Astrophysics Data System (ADS)

    Liska, Adam J.; Yang, Haishun; Milner, Maribeth; Goddard, Steve; Blanco-Canqui, Humberto; Pelton, Matthew P.; Fang, Xiao X.; Zhu, Haitao; Suyker, Andrew E.

    2014-05-01

    Removal of corn residue for biofuels can decrease soil organic carbon (SOC; refs , ) and increase CO2 emissions because residue C in biofuels is oxidized to CO2 at a faster rate than when added to soil. Net CO2 emissions from residue removal are not adequately characterized in biofuel life cycle assessment (LCA; refs , , ). Here we used a model to estimate CO2 emissions from corn residue removal across the US Corn Belt at 580 million geospatial cells. To test the SOC model, we compared estimated daily CO2 emissions from corn residue and soil with CO2 emissions measured using eddy covariance, with 12% average error over nine years. The model estimated residue removal of 6 Mg per ha-1 yr-1 over five to ten years could decrease regional net SOC by an average of 0.47-0.66 Mg C ha-1 yr-1. These emissions add an average of 50-70 g CO2 per megajoule of biofuel (range 30-90) and are insensitive to the fraction of residue removed. Unless lost C is replaced, life cycle emissions will probably exceed the US legislative mandate of 60% reduction in greenhouse gas (GHG) emissions compared with gasoline.

  10. State-level renewable portfolio standards: Evaluating their effectiveness in increasing renewable electricity generation and reducing carbon emissions

    NASA Astrophysics Data System (ADS)

    Denneny, Matthew J.

    The renewable portfolio standard (RPS) is a key state-level policy instrument meant to encourage renewable energy development and address climate change by mandating increased electricity generation from low-carbon renewable sources. In analyzing the effectiveness of RPS policies, I hypothesize that these policies should increase renewable electricity generation and reduce carbon dioxide emissions from electricity generation. Additionally, I hypothesize that more stringent RPS policies should allow for greater increases in renewable energy generation and larger declines in CO2 emissions. To test these hypotheses, I use pooled and fixed effects models to examine how RPS policies play a role in affecting renewable electricity generation and CO 2 emissions. My results suggest that these policies increase electricity generation from renewable sources and that the stringency of these policies matters. However, the results are mixed in regard to their effectiveness in reducing CO2 emissions. These findings suggest that RPS policies as they are now may not be the best way to reduce CO2 emissions. Other policies that more directly target emissions may be necessary for states to see the emissions reductions they desire.

  11. Semi-coke briquettes: towards reducing emissions of primary PM2.5, particulate carbon, and carbon monoxide from household coal combustion in China

    PubMed Central

    Li, Qing; Li, Xinghua; Jiang, Jingkun; Duan, Lei; Ge, Su; Zhang, Qi; Deng, Jianguo; Wang, Shuxiao; Hao, Jiming

    2016-01-01

    Direct household use of unprocessed raw coals for cooking and heating without any air pollution control device has caused serious indoor and outdoor environment problems by emitting particulate matter (PM) and gaseous pollutants. This study examined household emission reduction by switching from unprocessed bituminous and anthracite coals to processed semi-coke briquettes. Two typical stoves were used to test emission characteristics when burning 20 raw coal samples commonly used in residential heating activities and 15 semi-coke briquette samples which were made from bituminous coals by industrial carbonization treatment. The carbonization treatment removes volatile compounds from raw coals which are the major precursors for PM formation and carbon emission. The average emission factors of primary PM2.5, elemental carbon, organic carbon, and carbon monoxide for the tested semi-coke briquettes are much lower than those of the tested raw coals. Based on the current coal consumption data in China, switching to semi-coke briquettes can reduce average emission factors of these species by about 92%, 98%, 91%, and 34%, respectively. Additionally, semi-coke briquette has relatively lower price and higher burnout ratio. The replacement of raw coals with semi-coke briquettes is a feasible path to reduce pollution emissions from household activities. PMID:26782059

  12. Semi-coke briquettes: towards reducing emissions of primary PM2.5, particulate carbon, and carbon monoxide from household coal combustion in China

    NASA Astrophysics Data System (ADS)

    Li, Qing; Li, Xinghua; Jiang, Jingkun; Duan, Lei; Ge, Su; Zhang, Qi; Deng, Jianguo; Wang, Shuxiao; Hao, Jiming

    2016-01-01

    Direct household use of unprocessed raw coals for cooking and heating without any air pollution control device has caused serious indoor and outdoor environment problems by emitting particulate matter (PM) and gaseous pollutants. This study examined household emission reduction by switching from unprocessed bituminous and anthracite coals to processed semi-coke briquettes. Two typical stoves were used to test emission characteristics when burning 20 raw coal samples commonly used in residential heating activities and 15 semi-coke briquette samples which were made from bituminous coals by industrial carbonization treatment. The carbonization treatment removes volatile compounds from raw coals which are the major precursors for PM formation and carbon emission. The average emission factors of primary PM2.5, elemental carbon, organic carbon, and carbon monoxide for the tested semi-coke briquettes are much lower than those of the tested raw coals. Based on the current coal consumption data in China, switching to semi-coke briquettes can reduce average emission factors of these species by about 92%, 98%, 91%, and 34%, respectively. Additionally, semi-coke briquette has relatively lower price and higher burnout ratio. The replacement of raw coals with semi-coke briquettes is a feasible path to reduce pollution emissions from household activities.

  13. Semi-coke briquettes: towards reducing emissions of primary PM2.5, particulate carbon, and carbon monoxide from household coal combustion in China.

    PubMed

    Li, Qing; Li, Xinghua; Jiang, Jingkun; Duan, Lei; Ge, Su; Zhang, Qi; Deng, Jianguo; Wang, Shuxiao; Hao, Jiming

    2016-01-01

    Direct household use of unprocessed raw coals for cooking and heating without any air pollution control device has caused serious indoor and outdoor environment problems by emitting particulate matter (PM) and gaseous pollutants. This study examined household emission reduction by switching from unprocessed bituminous and anthracite coals to processed semi-coke briquettes. Two typical stoves were used to test emission characteristics when burning 20 raw coal samples commonly used in residential heating activities and 15 semi-coke briquette samples which were made from bituminous coals by industrial carbonization treatment. The carbonization treatment removes volatile compounds from raw coals which are the major precursors for PM formation and carbon emission. The average emission factors of primary PM2.5, elemental carbon, organic carbon, and carbon monoxide for the tested semi-coke briquettes are much lower than those of the tested raw coals. Based on the current coal consumption data in China, switching to semi-coke briquettes can reduce average emission factors of these species by about 92%, 98%, 91%, and 34%, respectively. Additionally, semi-coke briquette has relatively lower price and higher burnout ratio. The replacement of raw coals with semi-coke briquettes is a feasible path to reduce pollution emissions from household activities. PMID:26782059

  14. Adapting sustainable low-carbon techologies to reduce carbon dioxide emissions from coal-fired power plants in China

    NASA Astrophysics Data System (ADS)

    Kuo, Peter Shyr-Jye

    1997-09-01

    The scientific community is deeply concerned about the effect of greenhouse-gases (GHGs) on global climate change. A major climate shift can result in tragic destruction to our world. Carbon dioxide (COsb2) emissions from coal-fired power plants are major anthropogenic sources that contribute to potential global warming. The People's Republic of China, with its rapidly growing economy and heavy dependence on coal-fired power plants for electricity, faces increasingly serious environmental challenges. This research project seeks to develop viable methodologies for reducing the potential global warming effects and serious air pollution arising from excessive coal burning. China serves as a case study for this research project. Major resolution strategies are developed through intensive literature reviews to identify sustainable technologies that can minimize adverse environmental impacts while meeting China's economic needs. The research thereby contributes technological knowledge to the field of Applied Sciences. The research also integrates modern power generation technologies with China's current and future energy requirements. With these objectives in mind, this project examines how China's environmental issues are related to China's power generation methods. This study then makes strategic recommendations that emphasize low-carbon technologies as sustainable energy generating options to be implemented in China. These low-carbon technologies consist of three options: (1) using cleaner fuels converted from China's plentiful domestic coal resources; (2) applying high-efficiency gas turbine systems for power generation; and (3) integrating coal gasification processes with energy saving combined cycle gas turbine systems. Each method can perform independently, but a combined strategy can achieve the greatest COsb2 reductions. To minimize economic impacts caused by technological changes, this study also addresses additional alternatives that can be implemented in

  15. Household actions can provide a behavioral wedge to rapidly reduce US carbon emissions

    PubMed Central

    Dietz, Thomas; Gardner, Gerald T.; Gilligan, Jonathan; Stern, Paul C.; Vandenbergh, Michael P.

    2009-01-01

    Most climate change policy attention has been addressed to long-term options, such as inducing new, low-carbon energy technologies and creating cap-and-trade regimes for emissions. We use a behavioral approach to examine the reasonably achievable potential for near-term reductions by altered adoption and use of available technologies in US homes and nonbusiness travel. We estimate the plasticity of 17 household action types in 5 behaviorally distinct categories by use of data on the most effective documented interventions that do not involve new regulatory measures. These interventions vary by type of action and typically combine several policy tools and strong social marketing. National implementation could save an estimated 123 million metric tons of carbon per year in year 10, which is 20% of household direct emissions or 7.4% of US national emissions, with little or no reduction in household well-being. The potential of household action deserves increased policy attention. Future analyses of this potential should incorporate behavioral as well as economic and engineering elements. PMID:19858494

  16. When does highway construction to mitigate congestion reduce carbon emissions? A Case Study: The Caldecott Tunnel

    NASA Astrophysics Data System (ADS)

    Thurlow, M. E.; Maness, H.; Wiersema, D. J.; Mcdonald, B. C.; Harley, R.; Fung, I. Y.

    2014-12-01

    The construction of the fourth bore of the Caldecott Tunnel, which connects Oakland and Moraga, CA on State Route 24, was the second largest roadway construction project in California last year with a total cost of $417 million. The objective of the fourth bore was to reduce traffic congestion before the tunnel entrance in the off-peak direction of travel, but the project was a source of conflict between policy makers and environmental and community groups concerned about the air quality and traffic impacts. We analyze the impact of the opening of the fourth bore on CO2 emissions associated with traffic. We made surface observations of CO2from a mobile platform along State Route 24 for several weeks in November 2013 incorporating the period prior to and after the opening of the fourth bore on November 16, 2013. We directly compare bottom-up and top-down approaches to estimate the change in traffic emissions associated with the fourth bore opening. A bottom-up emissions inventory was derived from the high-resolution Performance Measurement System (PeMs) dataset and the Multi-scale Motor Vehicle and Equipment Emissions System (MOVES). The emissions inventory was used to drive a box model as well as a high-resolution regional transport model (the Weather and Regional Forecasting Model). The box model was also used to derive emissions from observations in a basic inversion. We also present an analysis of long-term traffic patterns and consider the potential for compensating changes in behavior that offset the observed emissions reductions on longer timescales. Finally, we examine how the results from the Caldecott study demonstrate the general benefit of using mobile measurements for quantifying environmental impacts of congestion mitigation projects.

  17. The sum of the parts: can we really reduce carbon emissions through individual behaviour change?

    PubMed

    Reynolds, Lucy

    2010-01-01

    Individuals are increasingly being urged to 'do their bit' in the fight against climate change, with governments and pro-environmentalists insisting that the collective impact of small behaviour changes will result in a meaningful reduction in global carbon emissions. The following paper considers this debate, as well as offering personal contributions from two leading environmentalists: Dr Doug McKenzie-Mohr, environmental psychologist and author of Fostering Sustainable Behavior: Community-Based Social Marketing; and Dr Tom Crompton, change strategist for WWF and co-author of Meeting Environmental Challenges: The Role of Human Identity, who argues for the role of intrinsic value systems in achieving sustainable behaviour change. As well as considering the responsibility of the individual in mitigating climate change, the paper introduces the discipline of social marketing as an effective tool for facilitating individual behaviour change, drawing on evidence from the field to recommend the key characteristics of effective behaviour change programmes. PMID:20333949

  18. Potential for reduced methane and carbon dioxide emissions from livestock and pasture management in the tropics

    PubMed Central

    Thornton, Philip K.; Herrero, Mario

    2010-01-01

    We estimate the potential reductions in methane and carbon dioxide emissions from several livestock and pasture management options in the mixed and rangeland-based production systems in the tropics. The impacts of adoption of improved pastures, intensifying ruminant diets, changes in land-use practices, and changing breeds of large ruminants on the production of methane and carbon dioxide are calculated for two levels of adoption: complete adoption, to estimate the upper limit to reductions in these greenhouse gases (GHGs), and optimistic but plausible adoption rates taken from the literature, where these exist. Results are expressed both in GHG per ton of livestock product and in Gt CO2-eq. We estimate that the maximum mitigation potential of these options in the land-based livestock systems in the tropics amounts to approximately 7% of the global agricultural mitigation potential to 2030. Using historical adoption rates from the literature, the plausible mitigation potential of these options could contribute approximately 4% of global agricultural GHG mitigation. This could be worth on the order of $1.3 billion per year at a price of $20 per t CO2-eq. The household-level and sociocultural impacts of some of these options warrant further study, however, because livestock have multiple roles in tropical systems that often go far beyond their productive utility. PMID:20823225

  19. Enhanced rice production but greatly reduced carbon emission following biochar amendment in a metal-polluted rice paddy.

    PubMed

    Zhang, Afeng; Bian, Rongjun; Li, Lianqing; Wang, Xudong; Zhao, Ying; Hussain, Qaiser; Pan, Genxing

    2015-12-01

    Soil amendment of biochar (BSA) had been shown effective for mitigating greenhouse gas (GHG) emission and alleviating metal stress to plants and microbes in soil. It has not yet been addressed if biochar exerts synergy effects on crop production, GHG emission, and microbial activity in metal-polluted soils. In a field experiment, biochar was amended at sequential rates at 0, 10, 20, and 40 t ha(-1), respectively, in a cadmium- and lead-contaminated rice paddy from the Tai lake Plain, China, before rice cropping in 2010. Fluxes of soil carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) were monitored using a static chamber method during the whole rice growing season (WRGS) of 2011. BSA significantly reduced soil CaCl2 extractable pool of Cd, and DTPA extractable pool of Cd and Pb. As compared to control, soil CO2 emission under BSA was observed to have no change at 10 t ha(-1) but decreased by 16-24% at 20 and 40 t ha(-1). In a similar trend, BSA at 20 and 40 t ha(-1) increased rice yield by 25-26% and thus enhanced ecosystem CO2 sequestration by 47-55% over the control. Seasonal total N2O emission was reduced by 7.1, 30.7, and 48.6% under BSA at 10, 20, and 40 t ha(-1), respectively. Overall, a net reduction in greenhouse gas balance (NGHGB) by 53.9-62.8% and in greenhouse gas intensity (GHGI) by 14.3-28.6% was observed following BSA at 20 and 40 t ha(-1). The present study suggested a great potential of biochar to enhancing grain yield while reducing carbon emission in metal-polluted rice paddies. PMID:26213131

  20. Curvature aided efficient axial field emission from carbon nanofiber-reduced graphene oxide superstructures on tungsten wire substrate

    NASA Astrophysics Data System (ADS)

    Jha, Arunava; Roy, Rajarshi; Sen, Dipayan; Chattopadhyay, Kalyan K.

    2016-03-01

    Field emission characteristics found in reduced graphene oxide (RGO) and RGO based composite systems have always been an area of research interest mainly due to presence of prolific quasi aligned edges working as emitter sites. However, the specific role and extent of edge curvature geometry in RGO systems in regards to the enhancement of field emission has not discussed thoroughly prior to this work. In this work we demonstrate enhanced axial field emission due to top assembly of thin RGO layer over a quasi-vertically aligned carbon nanofiber thin film supported on a tungsten wire substrate. Furthermore, simulation analysis for our RGO based hybrid system using finite element modeling showed that two-stage local field amplification in RGO is responsible for the overall improvement of field emission characteristics. In support of our findings, a tentative explanation has been proposed based on the additional emission from RGO edges in between the CNF network resulting to the enhancement of axial field emission in the nanocomposite superstructure.

  1. Strategies for reducing carbon emissions on the tropical rain forest: The case of the Brazilian Amazon

    SciTech Connect

    Freitas, M.A.V. de; Rosa, L.P.

    1995-11-01

    Forests systems are renewable resources that can be used by present generations and that should be available to future generations if they are exploited on a sustainable basis. The tropical forest is still an immense and unknown field. The issues are: What means a sustainable basis in the tropical rain forests? What are the means of harmonising an economic development with an environmental equilibrium in tropical regions? One way to meet this requirement is to analyse the potentially {open_quotes}no regrets{close_quotes} options on which it is possible to agree upon despite controversies about what will be the true long run costs and benefits of various courses of actions. In the case of the Brazilian Amazon, in the last thirty years, the use of biomass and land has increased rapidly. Therefore, environmental and social problems have emerged with some intensity and have had repercussions on local and global scales. In relation to the recent global environmental changes, the Brazilian Amazon is considered as a key region for biodiversity conservation and preserving a carbon sink. In this paper, the main methodological option is to conceive a set of {open_quotes}no-regret{close_quotes} options, related with the land uses and biomass valorisation, which are analysed through the same framework. The options considered here are: decrease of the great cattle ranching and of the predatory timber extraction; the increase of forest management (harvest of timber and nontimber extractive products) and forest plantations in the degraded lands. The aims to focus on three elements: job creation, technico-economic adequation and environmental impacts, with special regards concerning the limitation of the atmospheric emissions of greenhouse gases (carbon flow).

  2. Biodiversity losses and carbon emissions in Amazon region - the situation of contemporary period and strategies for reduce these environmental changes

    SciTech Connect

    Freitas, M.A.V. de; Aquino, L.C.; Rosa, L.P.

    1997-12-31

    The forest removal is a major contributor to local, regional and global environmental changes. Many of the tropical`s species are gravely threatened Numerous studies suggest that from 1970 to 1990 between 5 and 20 percent of the tropical`s species were committed to extinction. In 1995, the deforested lands in Brazilian Amazon account an amount Superior to 470,000 Km{sup 2}, old deforestation included, for a total surface of tropical`s rain forest of 3.4 and 3.8 million square kilometres. In 1990`s, the amount of carbon released to the atmosphere (as CO{sub 2}) from Brazilian Amazon deforestation was 3.5 % to 4.9 % and 250 % to 360 % of the World and Brazilian annual emission from fossil fuels, respectively. On the other hand, if deforestation is stopped and replaced with a rational forest management, a reuse of degraded lands for agro-forestry and biomass production for energy and industrial purposes, we can reduce the pressure on forests lands and the net carbon flux will be reversed. In this paper, we discuss the relations with biodiversity losses and carbon emissions in Brazilian Amazon region in the last thirty years and find suggest the principal`s strategies to reduce this environmental`s destruction.

  3. Cost of reducing carbon emissions in developing countries: Evidence from Columbia. Staff working paper No. 9

    SciTech Connect

    Linden, G.

    1993-06-01

    The author discusses the issue of the cost of reducing CO2 emissions related to the energy sector and the implications for the structure of the energy sector in Colombia. While there have been a number of attempts to estimate the costs of CO2 reduction in various developed countries such as the United States, there appears to be a lack of similar studies for developing countries. The analysis is based on optimizations using a comprehensive mathematical programming model of Colombia's energy sector in conjunction with an econometric model of the sector. Section one outlines the empirical methods used to analyze the energy/environmental linkages in Colombia. Section two summarizes the simulated results.

  4. Strategies for carbon sequestration and reducing greenhouse gas emissions from nursery production systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Currently two experiments are being conducted to determine the impact of the ornamental horticulture industry on GHG emissions and on C sequestration. One study focuses on the effect of nursery container size to begin indentifying components of the industry that may impact GHG emissions. In this stu...

  5. Multi-objective teaching-learning-based optimization algorithm for reducing carbon emissions and operation time in turning operations

    NASA Astrophysics Data System (ADS)

    Lin, Wenwen; Yu, D. Y.; Wang, S.; Zhang, Chaoyong; Zhang, Sanqiang; Tian, Huiyu; Luo, Min; Liu, Shengqiang

    2015-07-01

    In addition to energy consumption, the use of cutting fluids, deposition of worn tools and certain other manufacturing activities can have environmental impacts. All these activities cause carbon emission directly or indirectly; therefore, carbon emission can be used as an environmental criterion for machining systems. In this article, a direct method is proposed to quantify the carbon emissions in turning operations. To determine the coefficients in the quantitative method, real experimental data were obtained and analysed in MATLAB. Moreover, a multi-objective teaching-learning-based optimization algorithm is proposed, and two objectives to minimize carbon emissions and operation time are considered simultaneously. Cutting parameters were optimized by the proposed algorithm. Finally, the analytic hierarchy process was used to determine the optimal solution, which was found to be more environmentally friendly than the cutting parameters determined by the design of experiments method.

  6. Strategies for Carbon Sequestration and Reducing Greenhouse Gas Emissions from Nursery Production Systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Over the past three decades, no issue has received more attention from the scientific community than global warming and the possible impacts it may have on the global environment. Increased atmospheric carbon dioxide (CO2) concentration, along with those of other trace gases [i.e., methane (CH4), an...

  7. Forecasting carbon dioxide emissions.

    PubMed

    Zhao, Xiaobing; Du, Ding

    2015-09-01

    This study extends the literature on forecasting carbon dioxide (CO2) emissions by applying the reduced-form econometrics approach of Schmalensee et al. (1998) to a more recent sample period, the post-1997 period. Using the post-1997 period is motivated by the observation that the strengthening pace of global climate policy may have been accelerated since 1997. Based on our parameter estimates, we project 25% reduction in CO2 emissions by 2050 according to an economic and population growth scenario that is more consistent with recent global trends. Our forecasts are conservative due to that we do not have sufficient data to fully take into account recent developments in the global economy. PMID:26081307

  8. Potential for Woody Bioenergy Crops Grown on Marginal Lands in the US Midwest to Reduce Carbon Emissions

    NASA Astrophysics Data System (ADS)

    Sahajpal, R.; Hurtt, G. C.; Fisk, J. P.; Izaurralde, R. C.; Zhang, X.

    2012-12-01

    While cellulosic biofuels are widely considered to be a low carbon energy source for the future, a comprehensive assessment of the environmental sustainability of existing and future biofuel systems is needed to assess their utility in meeting US energy and food needs without exacerbating environmental harm. To assess the carbon emission reduction potential of cellulosic biofuels, we need to identify lands that are initially not storing large quantities of carbon in soil and vegetation but are capable of producing abundant biomass with limited management inputs, and accurately model forest production rates and associated input requirements. Here we present modeled results for carbon emission reduction potential and cellulosic ethanol production of woody bioenergy crops replacing existing native prairie vegetation grown on marginal lands in the US Midwest. Marginal lands are selected based on soil properties describing use limitation, and are extracted from the SSURGO (Soil Survey Geographic) database. Yield estimates for existing native prairie vegetation on marginal lands modeled using the process-based field-scale model EPIC (Environmental Policy Integrated Climate) amount to ~ 6.7±2.0 Mg ha-1. To model woody bioenergy crops, the individual-based terrestrial ecosystem model ED (Ecosystem Demography) is initialized with the soil organic carbon stocks estimated at the end of the EPIC simulation. Four woody bioenergy crops: willow, southern pine, eucalyptus and poplar are parameterized in ED. Sensitivity analysis of model parameters and drivers is conducted to explore the range of carbon emission reduction possible with variation in woody bioenergy crop types, spatial and temporal resolution. We hypothesize that growing cellulosic crops on these marginal lands can provide significant water quality, biodiversity and GHG emissions mitigation benefits, without accruing additional carbon costs from the displacement of food and feed production.

  9. The U.S. Federal Government's Efforts to Estimate an Economic Value for Reduced Carbon Emissions (Invited)

    NASA Astrophysics Data System (ADS)

    Wolverton, A.

    2010-12-01

    This presentation will summarize the technical process and results from recent U.S. Federal government efforts to estimate the “social cost of carbon” (SCC); the monetized damages associated with an incremental increase in carbon dioxide emissions in a given year. The purpose of the SCC estimates is to make it possible for Federal agencies to incorporate the social benefits from reducing CO2 emissions into cost-benefit analyses of regulatory actions that have relatively small impacts on cumulative global emissions. An interagency working group initiated a comprehensive analysis using three integrated assessment models. The interagency group chose to rely on three of the most widely recognized peer-reviewed models to fairly represent differences in the way in which economic impacts from climate change are modeled (DICE, PAGE, and FUND). The main objective of this process was to develop a range of SCC values using a defensible set of input assumptions grounded in the existing scientific and economic literatures. In this way, key uncertainties and model differences transparently and consistently inform the range of SCC estimates used in the rulemaking process. This proved challenging since the literature did not always agree on the best path forward. In some cases the group agreed to a range of assumptions to allow for uncertainty analysis (e.g., they include 5 different socioeconomic scenarios in the Monte Carlo analysis to reflect uncertainty about how future economic and population growth and energy systems will develop over the next 100 years). The four values selected for regulatory analysis included three estimates based on the average SCC from three integrated assessment models over a range of discount rates, since there is wide disagreement on which to apply in an inter-generational context. The fourth value represents the 95th percentile SCC estimate across all three models at a 3 percent discount rate and is included to represent higher

  10. 1992 Carbon emissions data

    SciTech Connect

    1995-12-31

    This article reports on the global total of carbon dioxide emissions from fossil-fuel burning and cement manufacture in 1992. The total estimate of 6097 million metric tons of carbon is essentially the same for 1990 and down slightly from 1991, but 7 of 9 geographical regions had increases.

  11. Potential of forest management to reduce French carbon emissions - regional modelling of the French forest carbon balance from the forest to the wood.

    NASA Astrophysics Data System (ADS)

    Valade, A.; Luyssaert, S.; Bellassen, V.; Vallet, P.

    2015-12-01

    In France the low levels of forest harvest (40 Mm3 per year over a volume increment of 89Mm3) is frequently cited to push for a more intensive management of the forest that would help reducing CO2 emissions. This reasoning overlooks the medium-to-long-term effects on the carbon uptake at the national scale that result from changes in the forest's structure and delayed emissions from products decay and bioenergy burning, both determinant for the overall C fluxes between the biosphere and the atmosphere. To address the impacts of an increase in harvest removal on biosphere-atmosphere carbon fluxes at national scale, we build a consistent regional modeling framework to integrate the forest-carbon system from photosynthesis to wood uses. We aim at bridging the gap between regional ecosystem modeling and land managers' considerations, to assess the synergistic and antagonistic effects of management strategies over C-based forest services: C-sequestration, energy and material provision, fossil fuel substitution. For this, we built on inventory data to develop a spatial forest growth simulator and design a novel method for diagnosing the current level of management based on stand characteristics (density, quadratic mean diameter or exploitability). The growth and harvest simulated are then processed with a life cycle analysis to account for wood transformation and uses. Three scenarii describe increases in biomass removals either driven by energy production target (set based on national prospective with a lock on minimum harvest diameters) or by changes in management practices (shorter or longer rotations, management of currently unmanaged forests) to be compared with business as usual simulations. Our management levels' diagnostics quantifies undermanagement at national scale and evidences the large weight of ownership-based undermanagement with an average of 26% of the national forest (between 10% and 40% per species) and thus represents a huge potential wood resource

  12. Role of lignin in reducing life-cycle carbon emissions, water use, and cost for United States cellulosic biofuels.

    PubMed

    Scown, Corinne D; Gokhale, Amit A; Willems, Paul A; Horvath, Arpad; McKone, Thomas E

    2014-01-01

    Cellulosic ethanol can achieve estimated greenhouse gas (GHG) emission reductions greater than 80% relative to gasoline, largely as a result of the combustion of lignin for process heat and electricity in biorefineries. Most studies assume lignin is combusted onsite, but exporting lignin to be cofired at coal power plants has the potential to substantially reduce biorefinery capital costs. We assess the life-cycle GHG emissions, water use, and capital costs associated with four representative biorefinery test cases. Each case is evaluated in the context of a U.S. national scenario in which corn stover, wheat straw, and Miscanthus are converted to 1.4 EJ (60 billion liters) of ethanol annually. Life-cycle GHG emissions range from 4.7 to 61 g CO2e/MJ of ethanol (compared with ∼ 95 g CO2e/MJ of gasoline), depending on biorefinery configurations and marginal electricity sources. Exporting lignin can achieve GHG emission reductions comparable to onsite combustion in some cases, reduce life-cycle water consumption by up to 40%, and reduce combined heat and power-related capital costs by up to 63%. However, nearly 50% of current U.S. coal-fired power generating capacity is expected to be retired by 2050, which will limit the capacity for lignin cofiring and may double transportation distances between biorefineries and coal power plants. PMID:24988448

  13. Forest carbon response to management scenarios intended to mitigate GHG emissions and reduce fire impacts in the US West Coast region

    NASA Astrophysics Data System (ADS)

    Hudiburg, T. W.; Law, B. E.; Thornton, P. E.; Luyssaert, S.

    2012-12-01

    US West coast forests are among the most carbon dense biomes in the world and the potential for biomass accumulation in mesic coastal forests is the highest recorded (Waring and Franklin 1979, Hudiburg et al. 2009). Greenhouse gas (GHG) mitigation strategies have recently expanded to include forest woody biomass as bioenergy, with the expectation that this will also reduce forest mortality. We examined forest carbon response and life cycle assessment (LCA) of net carbon emissions following varying combinations of bioenergy management scenarios in Pacific Northwest forests for the period from 2010-2100. We use the NCAR CLM4 model combined with a regional atmospheric forcing dataset and account for future environmental change using the IPCC RCP4.5 and RCP 8.5 scenarios. Bioenergy management strategies include a repeated thinning harvest, a repeated clearcut harvest, and a single salvage harvest in areas with projected insect-related mortality. None of the bioenergy management scenarios reduce net emissions to the atmosphere compared to continued business-as-usual harvest (BAU) by the end of the 21st century. Forest regrowth and reduced fire emissions are not large enough to balance the wood removals from harvest. Moreover, the substitution of wood for fossil fuel energy and products is not large enough to offset the wood losses through decomposition and combustion. However, in some ecoregions (Blue Mountains and East Cascades), emissions from the thinning harvests begin to improve over BAU at the end of the century and could lead to net reductions in those ecoregions over a longer time period (> 100 years). For salvage logging, there is no change compared to BAU emissions by the end of the 21st century because the treatment area is minimal compared to the other treatments and only performed once. These results suggest that managing forests for carbon sequestration will need to include a variety of approaches accounting for forest baseline conditions and in some

  14. Changing Arctic Ecosystems: Updated forecast: Reducing carbon dioxide (CO2) emissions required to improve polar bear outlook

    USGS Publications Warehouse

    Oakley, Karen L.; Atwood, Todd C.; Mugel, Douglas N.; Rode, Karyn D.; Whalen, Mary E.

    2015-01-01

    The Arctic is warming faster than other regions of the world due to the loss of snow and ice, which increases the amount of solar energy absorbed by the region. The most visible consequence has been the rapid decline in sea ice over the last 3 decades-a decline projected to bring long ice-free summers if greenhouse gas (GHG) emissions are not significantly reduced. The polar bear (Ursus maritimus) depends on sea ice over the biologically productive continental shelves of the Arctic Ocean as a platform for hunting seals. In 2008, the U.S. Fish and Wildlife Service listed the polar bear as threatened under the Endangered Species Act (ESA) due to the threat posed by sea ice loss. The polar bear was the first species to be listed due to forecasted population declines from climate change.

  15. The carbon emissions of Chinese cities

    NASA Astrophysics Data System (ADS)

    Wang, H.; Bi, J.; Zhang, R.; Liu, M.

    2012-03-01

    As increasing urbanization has become a national policy priority for economic growth in China, cities have become important players in efforts to reduce carbon emissions. However, their efforts have been hampered by the lack of specific and comparable carbon emission inventories. Comprehensive carbon emission inventories, which present both a relatively current snapshot and also show how emissions have changed over the past several years, of twelve Chinese cities were developed using bottom-up approach. Carbon emissions in most of Chinese cities rose along with economic growth from 2004 to 2008. Yet per capita carbon emissions varied between the highest and lowest emitting cities by a factor of nearly 7. Average per capita carbon emissions varied across sectors, including industrial energy consumption (64.3%), industrial processes (10.2%), transportation (10.6%), household energy consumption (8.0%), commercial energy consumption (4.3%) and waste processing (2.5%). The levels of per capita carbon emissions in China's cities were higher than we anticipated before comparing them with the average of global cities. This is mainly due to the major contribution of industry sector encompassing industrial energy consumption and industrial processes to the total carbon emissions of Chinese cities.

  16. FETC Programs for Reducing Greenhouse Gas Emissions

    SciTech Connect

    Ruether, J.A.

    1998-02-01

    Mark Twain once quipped that everyone talks about the weather but no one does anything about it. With interest in global climate change on the rise, researchers in the fossil-energy sector are feeling the heat to provide new technology to permit continued use of fossil fuels but with reduced emissions of so-called `greenhouse gases.` Three important greenhouse gases, carbon dioxide, methane, and nitrous oxide, are released to the atmosphere in the course of recovering and combusting fossil fuels. Their importance for trapping radiation, called forcing, is in the order given. In this report, we briefly review how greenhouse gases cause forcing and why this has a warming effect on the Earth`s atmosphere. Then we discuss programs underway at FETC that are aimed at reducing emissions of methane and carbon dioxide.

  17. Summary of the presentations at the international workshop on reducing carbon dioxide emissions from the developing world: Assessment of benefits, costs and barriers

    SciTech Connect

    Sathaye, J.; Goldman, N.

    1991-06-01

    The International Workshop on Reducing Carbon Dioxide Emissions from the Developing World: Assessment of Benefits, Costs and Barriers'' was the second workshop held as part of a project being conducted by the International Energy Studies Group of Lawrence Berkeley Laboratory, in collaboration with experts from leading institutions across the developing world. The goal of the project is to analyze long-range energy consumption in developing countries and its potential contribution to global climate change. The US Environmental Protection Agency (EPA) is supporting this work, the results of which already have made a key contribution to the technical analysis being used as the basis for discussion by the Energy and Industry Sub-group of the Intergovernmental Panel on Climate Change (IPCC). The main purpose of this workshop was two-fold: (1) to discuss the feasibility of implementing the efficiency improvements and fuel switching measures incorporated into the long-term energy scenarios created for 17 developing countries and (2) to examine the costs and benefits of reducing energy-related carbon dioxide emissions generated by developing countries.

  18. Summary of the presentations at the international workshop on reducing carbon dioxide emissions from the developing world: Assessment of benefits, costs and barriers

    SciTech Connect

    Sathaye, J.; Goldman, N.

    1991-06-01

    The ``International Workshop on Reducing Carbon Dioxide Emissions from the Developing World: Assessment of Benefits, Costs and Barriers`` was the second workshop held as part of a project being conducted by the International Energy Studies Group of Lawrence Berkeley Laboratory, in collaboration with experts from leading institutions across the developing world. The goal of the project is to analyze long-range energy consumption in developing countries and its potential contribution to global climate change. The US Environmental Protection Agency (EPA) is supporting this work, the results of which already have made a key contribution to the technical analysis being used as the basis for discussion by the Energy and Industry Sub-group of the Intergovernmental Panel on Climate Change (IPCC). The main purpose of this workshop was two-fold: (1) to discuss the feasibility of implementing the efficiency improvements and fuel switching measures incorporated into the long-term energy scenarios created for 17 developing countries and (2) to examine the costs and benefits of reducing energy-related carbon dioxide emissions generated by developing countries.

  19. Carbon Emission Flow in Networks

    PubMed Central

    Kang, Chongqing; Zhou, Tianrui; Chen, Qixin; Xu, Qianyao; Xia, Qing; Ji, Zhen

    2012-01-01

    As the human population increases and production expands, energy demand and anthropogenic carbon emission rates have been growing rapidly, and the need to decrease carbon emission levels has drawn increasing attention. The link between energy production and consumption has required the large-scale transport of energy within energy transmission networks. Within this energy flow, there is a virtual circulation of carbon emissions. To understand this circulation and account for the relationship between energy consumption and carbon emissions, this paper introduces the concept of “carbon emission flow in networks” and establishes a method to calculate carbon emission flow in networks. Using an actual analysis of China's energy pattern, the authors discuss the significance of this new concept, not only as a feasible approach but also as an innovative theoretical perspective. PMID:22761988

  20. Final Technical Report HFC Concrete: A Low­Energy, Carbon-Dioxide­Negative Solution for reducing Industrial Greenhouse Gas Emissions

    SciTech Connect

    Dr. Larry McCandlish, Principal Investigator; Dr. Richard Riman, Co-Principal Investigator

    2012-05-14

    Solidia/CCSM received funding for further research and development of its Low Temperature Solidification Process (LTS), which is used to create hydrate-free concrete (HFC). LTS/HFC is a technology/materials platform that offers wide applicability in the built infrastructure. Most importantly, it provides a means of making concrete without Portland cement. Cement and concrete production is a major consumer of energy and source of industrial greenhouse gas (GHG) emissions. The primary goal of this project was to develop and commercialize a novel material, HFC, which by replacing traditional concrete and cement, reduces both energy use and GHG emissions in the built infrastructure. Traditional concrete uses Portland Cement (PC) as a binder. PC production involves calcination of limestone at {approx}1450 C, which releases significant amounts of CO{sub 2} gas to the atmosphere and consumes a large amount of energy due to the high temperature required. In contrast, HFC is a carbonate-based hydrate-free concrete (HFC) that consumes CO{sub 2} gas in its production. HFC is made by reaction of silicate minerals with CO{sub 2} at temperatures below 100 C, more than an order-of-magnitude below the temperature required to make PC. Because of this significant difference in temperature, it is estimated that we will be able to reduce energy use in the cement and concrete industry by up to 30 trillion Btu by 2020. Because of the insulating properties of HFC, we believe we will also be able to significantly reduce energy use in the Building sector, though the extent of this saving is not yet quantified. It is estimated that production of a tonne of PC-based concrete requires about 6.2 million Btu of energy and produces over 1 tonne of CO{sub 2} emissions (Choate, 2003). These can be reduced to 1.9 million Btu and 0.025 tonnes of CO{sub 2} emissions per tonne of HFC (with overall CO{sub 2}-negativity possible by increasing carbonation yield). In this way, by replacing PC

  1. The carbon emissions of Chinese cities

    NASA Astrophysics Data System (ADS)

    Wang, H.; Zhang, R.; Liu, M.; Bi, J.

    2012-07-01

    As increasing urbanization has become a national policy priority for economic growth in China, cities have become important players in efforts to reduce carbon emissions. However, their efforts have been hampered by the lack of specific and comparable carbon emission inventories. Comprehensive carbon emission inventories for twelve Chinese cities, which present both a relatively current snapshot and also show how emissions have changed over the past several years, were developed using a bottom-up approach. Carbon emissions in most Chinese cities rose along with economic growth from 2004 to 2008. Yet per capita carbon emissions varied between the highest and lowest emitting cities by a factor of nearly 7. Average contributions of sectors to per capita emissions for all Chinese cities were 65.1% for industrial energy consumption, 10.1% for industrial processes, 10.4% for transportation, 7.7% for household energy consumption, 4.2% for commercial energy consumption and 2.5% for waste processing. However, these shares are characterized by considerable variability due to city-specific factors. The levels of per capita carbon emissions in China's cities were higher than we anticipated before comparing them with the average of ten cities in other parts of the world. This is mainly due to the major contribution of the industry sector in Chinese cities.

  2. Burner retrofits reduce brewery emissions

    SciTech Connect

    Not Available

    1993-04-01

    In 1988, the South Coast Air Quality Management District in California (SCAQMD) tightened its grip on industrial emissions of nitrogen oxides (NOx). The new statute, Rule 1146, mandates a 75% reduction in NOx emissions over a five-year period ending this July. Anheuser-Busch Inc.'s second-largest brewery in Van Nuys fell under the new law's jurisdiction. Under the new law, the maximum allowable NOx emission must be reduced from 120 to 30 ppm for the two largest boilers. There were two alternatives: either prevent its formation inside the boiler, or remove it from the off-gases via selective catalytic reduction (SCR) or selective non-catalytic reduction (SNCR). Prevention was chosen, because the NOx-removal technologies are unproven in the US on natural-gas-fired boilers. In addition, it was not known whether SCR or SNCR could respond to the wide swings in boiler demand. At any given time, loads between 30 and 100% of capacity would be required from the boilers. The brewery retrofitted the 125,000-lb/h boilers with Variflame burners, based upon an earlier retrofit at Anheuser-Busch's Merrimack, N.H., brewery. The paper describes this burner and its performance.

  3. Reducing carbon dioxide to products

    SciTech Connect

    Cole, Emily Barton; Sivasankar, Narayanappa; Parajuli, Rishi; Keets, Kate A

    2014-09-30

    A method reducing carbon dioxide to one or more products may include steps (A) to (C). Step (A) may bubble said carbon dioxide into a solution of an electrolyte and a catalyst in a divided electrochemical cell. The divided electrochemical cell may include an anode in a first cell compartment and a cathode in a second cell compartment. The cathode may reduce said carbon dioxide into said products. Step (B) may adjust one or more of (a) a cathode material, (b) a surface morphology of said cathode, (c) said electrolyte, (d) a manner in which said carbon dioxide is bubbled, (e), a pH level of said solution, and (f) an electrical potential of said divided electrochemical cell, to vary at least one of (i) which of said products is produced and (ii) a faradaic yield of said products. Step (C) may separate said products from said solution.

  4. The future of forests and orangutans (Pongo abelii) in Sumatra: predicting impacts of oil palm plantations, road construction, and mechanisms for reducing carbon emissions from deforestation

    NASA Astrophysics Data System (ADS)

    Gaveau, David L. A.; Wich, Serge; Epting, Justin; Juhn, Daniel; Kanninen, Markku; Leader-Williams, Nigel

    2009-09-01

    Payments for reduced carbon emissions from deforestation (RED) are now attracting attention as a way to halt tropical deforestation. Northern Sumatra comprises an area of 65 000 km2 that is both the site of Indonesia's first planned RED initiative, and the stronghold of 92% of remaining Sumatran orangutans. Under current plans, this RED initiative will be implemented in a defined geographic area, essentially a newly established, 7500 km2 protected area (PA) comprising mostly upland forest, where guards will be recruited to enforce forest protection. Meanwhile, new roads are currently under construction, while companies are converting lowland forests into oil palm plantations. This case study predicts the effectiveness of RED in reducing deforestation and conserving orangutans for two distinct scenarios: the current plan of implementing RED within the specific boundary of a new upland PA, and an alternative scenario of implementing RED across landscapes outside PAs. Our satellite-based spatially explicit deforestation model predicts that 1313 km2 of forest would be saved from deforestation by 2030, while forest cover present in 2006 would shrink by 22% (7913 km2) across landscapes outside PAs if RED were only to be implemented in the upland PA. Meanwhile, orangutan habitat would reduce by 16% (1137 km2), resulting in the conservative loss of 1384 orangutans, or 25% of the current total population with or without RED intervention. By contrast, an estimated 7824 km2 of forest could be saved from deforestation, with maximum benefit for orangutan conservation, if RED were to be implemented across all remaining forest landscapes outside PAs. Here, RED payments would compensate land users for their opportunity costs in not converting unprotected forests into oil palm, while the construction of new roads to service the marketing of oil palm would be halted. Our predictions suggest that Indonesia's first RED initiative in an upland PA may not significantly reduce

  5. Trading permanent and temporary carbon emissions credits

    SciTech Connect

    Marland, Gregg; Marland, Eric

    2009-08-01

    In this issue of Climatic Change, Van Kooten (2009) addresses an issue that has bedeviled negotiators since the drafting stage of the Kyoto Protocol. If we accept that increasing withdrawals of carbon dioxide from the atmpshere has the same net impact on the climate system as reducing emissions of carbon dioxide to the atmosphere, how do we design a system that allows trading of one for the other? As van Kooten expresses the challenge: 'The problem is that emissions reduction and carbon sequestration, while opposite sides of the same coin in some sense, are not directly comparable, thereby inhibiting their trade in carbon markets.' He explains: 'The difficulty centers on the length of time that mitigation strategies without CO{sub 2} from entering the atmosphere - the duration problem.' While reducing emissions of CO{sub 2} represents an essentially permanent benefit for the atmosphere, capturing CO{sub 2} that has been produced (whether capture is from the atmosphere or directly from, for example, the exhaust from power plants) there is the challenge of storing the carbon adn the risk that it will yet escape to the atmosphere. Permanent benefit to the atmosphere is often not assured for carbon sequestration activities. This is especially true if the carbon is taken up and stored in the biosphere - e.g. in forest trees or agricultural soils.

  6. Cermet Filters To Reduce Diesel Engine Emissions

    SciTech Connect

    Kong, Peter

    2001-08-05

    Pollution from diesel engines is a significant part of our nation's air-quality problem. Even under the more stringent standards for heavy-duty engines set to take effect in 2004, these engines will continue to emit large amounts of nitrogen oxides and particulate matter, both of which affect public health. To address this problem, the Idaho National Engineering and Environmental Laboratory (INEEL) invented a self-cleaning, high temperature, cermet filter that reduces heavy-duty diesel engine emissions. The main advantage of the INEEL cermet filter, compared to current technology, is its ability to destroy carbon particles and NOx in diesel engine exhaust. As a result, this technology is expected to improve our nation's environmental quality by meeting the need for heavy-duty diesel engine emissions control. This paper describes the cermet filter technology and the initial research and development effort.Diesel engines currently emit soot and NOx that pollute our air. It is expected that the U.S. Environmental Protection Agency (EPA) will begin tightening the regulatory requirements to control these emissions. The INEEL's self-cleaning, high temperature cermet filter provides a technology to clean heavy-duty diesel engine emissions. Under high engine exhaust temperatures, the cermet filter simultaneously removes carbon particles and NOx from the exhaust gas. The cermet filter is made from inexpensive starting materials, via net shape bulk forming and a single-step combustion synthesis process, and can be brazed to existing structures. It is self-cleaning, lightweight, mechanically strong, thermal shock resistant, and has a high melting temperature, high heat capacity, and controllable thermal expansion coefficient. The filter's porosity is controlled to provide high removal efficiency for carbon particulate. It can be made catalytic to oxidize CO, H2, and hydrocarbons, and reduce NOx. When activated by engine exhaust, the filter produces NH3 and light hydrocarbon

  7. Carbon emission from global hydroelectric reservoirs revisited.

    PubMed

    Li, Siyue; Zhang, Quanfa

    2014-12-01

    Substantial greenhouse gas (GHG) emissions from hydropower reservoirs have been of great concerns recently, yet the significant carbon emitters of drawdown area and reservoir downstream (including spillways and turbines as well as river reaches below dams) have not been included in global carbon budget. Here, we revisit GHG emission from hydropower reservoirs by considering reservoir surface area, drawdown zone and reservoir downstream. Our estimates demonstrate around 301.3 Tg carbon dioxide (CO2)/year and 18.7 Tg methane (CH4)/year from global hydroelectric reservoirs, which are much higher than recent observations. The sum of drawdown and downstream emission, which is generally overlooked, represents 42 % CO2 and 67 % CH4 of the total emissions from hydropower reservoirs. Accordingly, the global average emissions from hydropower are estimated to be 92 g CO2/kWh and 5.7 g CH4/kWh. Nonetheless, global hydroelectricity could currently reduce approximate 2,351 Tg CO2eq/year with respect to fuel fossil plant alternative. The new findings show a substantial revision of carbon emission from the global hydropower reservoirs. PMID:24943886

  8. Reducing environmental emissions in tanneries.

    PubMed

    van Groenestijn, J W; Langerwerf, J S A; Lucas, M

    2002-01-01

    Tanning, in particular chrome leather production, is still characterised by an inefficient use of raw material and the production of highly polluted wastewater and solid wastes. A part of the emissions can be prevented by introducing clean tanning technologies, the remaining emissions can be treated. Clean production technologies and waste (water) treatment technologies should have a designed complimentarity. Anaerobic wastewater treatment with recovery of sulfides, sulfur and energy (biogas) is a cornerstone in such integral clean chrome leather technology. PMID:12046670

  9. Methods for reducing pollutant emissions from jet aircraft

    NASA Technical Reports Server (NTRS)

    Butze, H. F.

    1971-01-01

    Pollutant emissions from jet aircraft and combustion research aimed at reducing these emissions are defined. The problem of smoke formation and results achieved in smoke reduction from commercial combustors are discussed. Expermental results of parametric tests performed on both conventional and experimental combustors over a range of combustor-inlet conditions are presented. Combustor design techniques for reducing pollutant emissions are discussed. Improved fuel atomization resulting from the use of air-assist fuel nozzles has brought about significant reductions in hydrocarbon and carbon monoxide emissions at idle. Diffuser tests have shown that the combustor-inlet airflow profile can be controlled through the use of diffuser-wall bleed and that it may thus be possible to reduce emissions by controlling combustor airflow distribution. Emissions of nitric oxide from a shortlength annular swirl-can combustor were significantly lower than those from a conventional combustor operating at similar conditions.

  10. Distributed Energy Resources for Carbon Emissions Mitigation

    SciTech Connect

    Firestone, Ryan; Marnay, Chris

    2007-05-01

    The era of publicly mandated GHG emissions restrictions inthe United States has begun with recent legislation in California andseven northeastern states. Commercial and industrial buildings canimprove the carbon-efficiency of end-use energy consumption by installingtechnologies such as on-site cogeneration of electricity and useful heatin combined heat and power systems, thermally-activated cooling, solarelectric and thermal equipment, and energy storage -- collectively termeddistributed energy resources (DER). This research examines a collectionof buildings in California, the Northeast, and the southern United Statesto demonstrate the effects of regional characteristics such as the carbonintensity of central electricity grid, the climate-driven demand forspace heating and cooling, and the availability of solar insolation. Theresults illustrate that the magnitude of a realistic carbon tax ($100/tC)is too small to incent significant carbon-reducing effects oneconomically optimal DER adoption. In large part, this is because costreduction and carbon reduction objectives are roughly aligned, even inthe absence of a carbon tax.

  11. Methods To Reduce Soil Fumigation Emissions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil fumigation is an important management practice for controlling soil pests in many high value crops including almonds. Reducing atmospheric emissions is necessary to minimize the environmental impact of soil fumigation. Water seals (sprinkling water on soil surface) to reduce fumigant emissions...

  12. Will peak oil accelerate carbon dioxide emissions?

    NASA Astrophysics Data System (ADS)

    Caldeira, K.; Davis, S. J.; Cao, L.

    2008-12-01

    The relative scarcity of oil suggests that oil production is peaking and will decline thereafter. Some have suggested that this represents an opportunity to reduce carbon dioxide emissions. However, in the absence of constraints on carbon dioxide emission, "peak oil" may drive a shift towards increased reliance on coal as a primary energy source. Because coal per unit energy, in the absence of carbon capture and disposal, releases more carbon dioxide to the atmosphere than oil, "peak oil" may lead to an acceleration of carbon dioxide emissions. We will never run out of oil. As oil becomes increasingly scarce, prices will rise and therefore consumption will diminish. As prices rise, other primary energy sources will become increasingly competitive with oil. The developed world uses oil primarily as a source of transportation fuels. The developing world uses oil primarily for heat and power, but the trend is towards increasing reliance on oil for transportation. Liquid fuels, including petroleum derivatives such as gasoline and diesel fuel, are attractive as transportation fuels because of their relative abundance of energy per unit mass and volume. Such considerations are especially important for the air transport industry. Today, there is little that can compete with petroleum-derived transportation fuels. Future CO2 emissions from the transportation sector largely depend on what replaces oil as a source of fuel. Some have suggested that biomass-derived ethanol, hydrogen, or electricity could play this role. Each of these potential substitutes has its own drawbacks (e.g., low power density per unit area in the case of biomass, low power density per unit volume in the case of hydrogen, and low power density per unit mass in the case of battery storage). Thus, it is entirely likely that liquefaction of coal could become the primary means by which transportation fuels are produced. Since the burning of coal produces more CO2 per unit energy than does the burning of

  13. Technology Opportunities to Reduce U.S. Greenhouse Gas Emissions

    SciTech Connect

    National Lab Directors, . .

    2001-04-05

    The rise in greenhouse gas emissions from fossil fuel combustion and industrial and agricultural activities has aroused international concern about the possible impacts of these emissions on climate. Greenhouse gases--mostly carbon dioxide, some methane, nitrous oxide and other trace gases--are emitted to the atmosphere, enhancing an effect in which heat reflected from the earth's surface is kept from escaping into space, as in a greenhouse. Thus, there is concern that the earth's surface temperature may rise enough to cause global climate change. Approximately 90% of U.S. greenhouse gas emissions from anthropogenic sources come from energy production and use, most of which are a byproduct of the combustion of fossil fuels. On a per capita basis, the United States is one of the world's largest sources of greenhouse gas emissions, comprising 4% of the world's population, yet emitting 23% of the world's greenhouse gases. Emissions in the United States are increasing at around 1.2% annually, and the Energy Information Administration forecasts that emissions levels will continue to increase at this rate in the years ahead if we proceed down the business-as-usual path. President Clinton has presented a two-part challenge for the United States: reduce greenhouse gas emissions and grow the economy. Meeting the challenge will mean that in doing tomorrow's work, we must use energy more efficiently and emit less carbon for the energy expended than we do today. To accomplish these goals, President Clinton proposed on June 26, 1997, that the United States ''invest more in the technologies of the future''. In this report to Secretary of Energy Pena, 47 technology pathways are described that have significant potential to reduce carbon dioxide emissions. The present study was completed before the December 1997 United Nations Framework Convention on Climate Change and is intended to provide a basis to evaluate technology feasibility and options to reduce greenhouse gas emissions

  14. Carbon emissions of infrastructure development.

    PubMed

    Müller, Daniel B; Liu, Gang; Løvik, Amund N; Modaresi, Roja; Pauliuk, Stefan; Steinhoff, Franciska S; Brattebø, Helge

    2013-10-15

    Identifying strategies for reconciling human development and climate change mitigation requires an adequate understanding of how infrastructures contribute to well-being and greenhouse gas emissions. While direct emissions from infrastructure use are well-known, information about indirect emissions from their construction is highly fragmented. Here, we estimated the carbon footprint of the existing global infrastructure stock in 2008, assuming current technologies, to be 122 (-20/+15) Gt CO2. The average per-capita carbon footprint of infrastructures in industrialized countries (53 (± 6) t CO2) was approximately 5 times larger that that of developing countries (10 (± 1) t CO2). A globalization of Western infrastructure stocks using current technologies would cause approximately 350 Gt CO2 from materials production, which corresponds to about 35-60% of the remaining carbon budget available until 2050 if the average temperature increase is to be limited to 2 °C, and could thus compromise the 2 °C target. A promising but poorly explored mitigation option is to build new settlements using less emissions-intensive materials, for example by urban design; however, this strategy is constrained by a lack of bottom-up data on material stocks in infrastructures. Infrastructure development must be considered in post-Kyoto climate change agreements if developing countries are to participate on a fair basis. PMID:24053762

  15. Reducing emissions from uranium dissolving

    SciTech Connect

    Griffith, W.L.; Compere, A.L.; Huxtable, W.P.; Googin, J.M.

    1992-10-01

    This study was designed to assess the feasibility of decreasing NO{sub x} emissions from the current uranium alloy scrap tray dissolving facility. In the current process, uranium scrap is dissolved in boiling nitric acid in shallow stainless-steel trays. As scrap dissolves, more metal and more nitric acid are added to the tray by operating personnel. Safe geometry is assured by keeping liquid level at or below 5 cm, the depth of a safe infinite slab. The accountability batch control system provides additional protection against criticality. Both uranium and uranium alloys are dissolved. Nitric acid is recovered from the vapors for reuse. Metal nitrates are sent to uranium recovery. Brown NO{sub x} fumes evolved during dissolving have occasionally resulted in a visible plume from the trays. The fuming is most noticeable during startup and after addition of fresh acid to a tray. Present environmental regulations are expected to require control of brown NO{sub x} emissions. A detailed review of the literature, indicated the feasibility of slightly altering process chemistry to favor the production of NO{sub 2} which can be scrubbed and recycled as nitric acid. Methods for controlling the process to manage offgas product distribution and to minimize chemical reaction hazards were also considered.

  16. Reducing emissions from uranium dissolving

    SciTech Connect

    Griffith, W.L.; Compere, A.L.; Huxtable, W.P.; Googin, J.M.

    1992-10-01

    This study was designed to assess the feasibility of decreasing NO[sub x] emissions from the current uranium alloy scrap tray dissolving facility. In the current process, uranium scrap is dissolved in boiling nitric acid in shallow stainless-steel trays. As scrap dissolves, more metal and more nitric acid are added to the tray by operating personnel. Safe geometry is assured by keeping liquid level at or below 5 cm, the depth of a safe infinite slab. The accountability batch control system provides additional protection against criticality. Both uranium and uranium alloys are dissolved. Nitric acid is recovered from the vapors for reuse. Metal nitrates are sent to uranium recovery. Brown NO[sub x] fumes evolved during dissolving have occasionally resulted in a visible plume from the trays. The fuming is most noticeable during startup and after addition of fresh acid to a tray. Present environmental regulations are expected to require control of brown NO[sub x] emissions. A detailed review of the literature, indicated the feasibility of slightly altering process chemistry to favor the production of NO[sub 2] which can be scrubbed and recycled as nitric acid. Methods for controlling the process to manage offgas product distribution and to minimize chemical reaction hazards were also considered.

  17. Reducing Emissions from Uranium Dissolving

    SciTech Connect

    Griffith, W.L.

    1992-01-01

    This study was designed to assess the feasibility of decreasing NO{sub x} emissions from the current uranium alloy scrap tray dissolving facility. In the current process, uranium scrap is dissolved in boiling nitric acid in shallow stainless-steel trays. As scrap dissolves, more metal and more nitric acid are added to the tray by operating personnel. Safe geometry is assured by keeping liquid level at or below 5 cm, the depth of a safe infinite slab. The accountability batch control system provides additional protection against criticality. The trays are steam coil heated. The process has operated satisfactorily, with few difficulties, for decades. Both uranium and uranium alloys are dissolved. Nitric acid is recovered from the vapors for reuse. Metal nitrates are sent to uranium recovery. Brown NO{sub x} fumes evolved during dissolving have occasionally resulted in a visible plume from the trays. The fuming is most noticeable during startup and after addition of fresh acid to a tray. Present environmental regulations are expected to require control of brown NO{sub x} emissions. Because NO{sub x} is hazardous, fumes should be suppressed whenever the electric blower system is inoperable. Because the tray dissolving process has worked well for decades, as much of the current capital equipment and operating procedures as possible were preserved. A detailed review of the literature, indicated the feasibility of slightly altering process chemistry to favor the production of NO{sub 2}, which can be scrubbed and recycled as nitric acid. Methods for controlling the process to manage offgas product distribution and to minimize chemical reaction hazards were also considered.

  18. Carbon reduction emissions in South Africa

    SciTech Connect

    Temchin, Jerome

    2002-02-28

    This project is a feasibility study for a control system for existing backup generators in South Africa. The strategy is to install a system to enable backup generators (BGs) to be dispatched only when a large generator fails. Using BGs to provide ''ten minute reserve'' will save energy and reduce emissions of greenhouse gases by an estimated nearly 500,000 tons of carbon dioxide per year.

  19. Method of reducing NOx emissions in gasoline vehicles

    SciTech Connect

    Gwyn, J.E.

    1993-08-10

    An unleaded fuel composition is described comprising a major amount of a hydrocarbon base fuel of the gasoline boiling range containing an amount effective to reduce NO[sub x] emissions from electronic port fuel injected engines of an ammonium compound selected from the group consisting of ammonium formate, ammonium propionate, ammonium dicitrate, ammonium carbamate, ammonium carbonate, ammonium acetate, and admixtures thereof.

  20. Reducing the carbon footprint of Canadian peat extraction and restoration.

    PubMed

    Waddington, James M; Plach, Janina; Cagampan, Jason P; Lucchese, Maria; Strack, Maria

    2009-06-01

    The Canadian horticultural peat industry generates carbon emissions through various methods of peat extraction, processing, and land-use changes. This study provides a carbon emissions analysis comparing the traditional vacuum harvest (VH) and block-cut (BC) extraction techniques to a new acrotelm transplant (AT) method that restores natural peatland function by preserving and replacing the surface layer vegetation as part of the extraction process. The relative global warming potential for each extraction method was determined by estimating carbon dioxide (CO2) and methane exchange for each phase of peat extraction, including emissions from land-use change and machinery fuel consumption. Preliminary findings, based on 1 y of measurements, indicate that the AT technique has the lowest annual carbon emissions compared to the VH and BC methods. Projected total carbon emissions from a 75-ha peatland after 50 y of extraction using the AT technique produced a sink of approximately 3300 t CO2 equivalents (CO2-e). This represents a marked reduction in total carbon emissions estimated for the VH (19 000 t CO2-e) and BC (29 000 t CO2-e) extraction techniques. This analysis suggests that the AT method reestablishes peat accumulation and peatland carbon storage function more effectively than the VH and BC methods, which are associated with delayed restoration efforts. Consequently, the AT technique has the potential to greatly reduce the carbon footprint of the Canadian horticultural peat industry. PMID:19739553

  1. Carbon emission from farm operations.

    PubMed

    Lal, R

    2004-09-01

    This manuscript is a synthesis of the available information on energy use in farm operations, and its conversion into carbon equivalent (CE). A principal advantage of expressing energy use in terms of carbon (C) emission as kg CE lies in its direct relation to the rate of enrichment of atmospheric concentration of CO2. Synthesis of the data shows that estimates of emissions in kg CE/ha are 2-20 for different tillage operations, 1-1.4 for spraying chemicals, 2-4 for drilling or seeding and 6-12 for combine harvesting. Similarly, estimates of C emissions in kg CE/kg for different fertilizer nutrients are 0.9-1.8 for N, 0.1-0.3 for P2O5, 0.1-0.2 for K20 and 0.03-0.23 for lime. Estimates of C emission in kg CE/kg of active ingredient (a.i.) of different pesticides are 6.3 for herbicides, 5.1 for insecticides and 3.9 for fungicides. Irrigation, lifting water from deep wells and using sprinkling systems, emits 129+/-98 kg CE for applying 25 cm of water and 258+/-195 for 50 cm of water. Emission for different tillage methods are 35.3 kg CE/ha for conventional till, 7.9 kg CE/ha for chisel till or minimum till, and 5.8 kg CE/ha for no-till method of seedbed preparation. In view of the high C costs of major inputs, sustainable management of agricultural ecosystems implies that an output/input ratio, expressed either as gross or net output of C, must be >1 and has an increasing trend over time. PMID:15196846

  2. Field emission study of carbon nanostructures

    NASA Astrophysics Data System (ADS)

    Zhao, Xin

    Recently, carbon nanosheets (CNS), a novel nanostructure, were developed in our laboratory as a field emission source for high emission current. To characterize, understand and improve the field emission properties of CNS, a ultra-high vacuum surface analysis system was customized to conduct relevant experimental research in four distinct areas. The system includes Auger electron spectroscopy (AES), field emission energy spectroscopy (FEES), field emission I-V testing, and thermal desorption spectroscopy (TDS). Firstly, commercial Mo single tips were studied to calibrate the customized system. AES and FEES experiments indicate that a pyramidal nanotip of Ca and O elements formed on the Mo tip surface by field induced surface diffusion. Secondly, field emission I-V testing on CNS indicates that the field emission properties of pristine nanosheets are impacted by adsorbates. For instance, in pristine samples, field emission sources can be built up instantaneously and be characterized by prominent noise levels and significant current variations. However, when CNS are processed via conditioning (run at high current), their emission properties are greatly improved and stabilized. Furthermore, only H2 desorbed from the conditioned CNS, which indicates that only H adsorbates affect emission. Thirdly, the TDS study on nanosheets revealed that the predominant locations of H residing in CNS are sp2 hybridized C on surface and bulk. Fourthly, a fabricating process was developed to coat low work function ZrC on nanosheets for field emission enhancement. The carbide triple-peak in the AES spectra indicated that Zr carbide formed, but oxygen was not completely removed. The Zr(CxOy) coating was dispersed as nanobeads on the CNS surface. Although the work function was reduced, the coated CNS emission properties were not improved due to an increased beta factor. Further analysis suggest that for low emission current (<1 uA), the H adsorbates affect emission by altering the work

  3. CARBON EMISSIONS ECONOMIC INTENSITY INDEX (CEEII)

    EPA Science Inventory

    The core concept of the CEEII is to understand, at the state level, the carbon emissions from energy consumption in relation to the value of the activity that generates the emissions. The CEEII treats carbon emissions as an input to producing the activity’s value and assesses th...

  4. Reducing exhaust gas emissions from Citydiesel busses

    NASA Astrophysics Data System (ADS)

    Mikkonen, Seppo

    The effect of fuel composition and exhaust gas aftertreatment on the emissions was measured from truck and bus engines. Possibilities to measure unregulated emissions (aldehydes, polyaromatic hydrocarbons, mutagenicity) were built. A reformulated diesel fuel 'Citydiesel' was developed. Citydiesel was able to reduce emissions compared to standard diesel fuel as follows: particulates by 10 to 30%, nitrogen oxides by 2 to 10%, sulphur dioxide by 97%, polyaromatic hydrocarbons (PAH) over 50%, mutagenicity of the exhaust particulates clearly, odor of the exhaust, and smoke after a cold start. The use of Citydiesel fuel reduces emissions of the existing vehicles immediately which is a remarkable benefit. The very low sulphur content (below 50 ppm) makes it possible to use oxidation. catalytic converters to reduce emissions of diesel vehicles. The new Euro 2 exhaust regulations coming into force during 1996 can be met with a modern diesel engine, Citydiesel fuel, and exhaust gas aftertreatment. Properties of Citydiesel fuel were verified in a three year field test with 140 city buses. Experience was good; e.g., engine oil change interval could be lengthened. Total value of the exhaust was estimated with different fuels and aftertreatment device in order to find out cheap ways to reduce emissions.

  5. Method for reducing CO2, CO, NOX, and SOx emissions

    DOEpatents

    Lee, James Weifu; Li, Rongfu

    2002-01-01

    Industrial combustion facilities are integrated with greenhouse gas-solidifying fertilizer production reactions so that CO.sub.2, CO, NO.sub.x, and SO.sub.x emissions can be converted prior to emission into carbonate-containing fertilizers, mainly NH.sub.4 HCO.sub.3 and/or (NH.sub.2).sub.2 CO, plus a small fraction of NH.sub.4 NO.sub.3 and (NH.sub.4).sub.2 SO.sub.4. The invention enhances sequestration of CO.sub.2 into soil and the earth subsurface, reduces N0.sub.3.sup.- contamination of surface and groundwater, and stimulates photosynthetic fixation of CO.sub.2 from the atmosphere. The method for converting CO.sub.2, CO, NO.sub.x, and SO.sub.x emissions into fertilizers includes the step of collecting these materials from the emissions of industrial combustion facilities such as fossil fuel-powered energy sources and transporting the emissions to a reactor. In the reactor, the CO.sub.2, CO, N.sub.2, SO.sub.x, and/or NO.sub.x are converted into carbonate-containing fertilizers using H.sub.2, CH.sub.4, or NH.sub.3. The carbonate-containing fertilizers are then applied to soil and green plants to (1) sequester inorganic carbon into soil and subsoil earth layers by enhanced carbonation of groundwater and the earth minerals, (2) reduce the environmental problem of NO.sub.3.sup.- runoff by substituting for ammonium nitrate fertilizer, and (3) stimulate photosynthetic fixation of CO.sub.2 from the atmosphere by the fertilization effect of the carbonate-containing fertilizers.

  6. Alternative industrial carbon emissions benchmark based on input-output analysis

    NASA Astrophysics Data System (ADS)

    Han, Mengyao; Ji, Xi

    2016-05-01

    Some problems exist in the current carbon emissions benchmark setting systems. The primary consideration for industrial carbon emissions standards highly relate to direct carbon emissions (power-related emissions) and only a portion of indirect emissions are considered in the current carbon emissions accounting processes. This practice is insufficient and may cause double counting to some extent due to mixed emission sources. To better integrate and quantify direct and indirect carbon emissions, an embodied industrial carbon emissions benchmark setting method is proposed to guide the establishment of carbon emissions benchmarks based on input-output analysis. This method attempts to link direct carbon emissions with inter-industrial economic exchanges and systematically quantifies carbon emissions embodied in total product delivery chains. The purpose of this study is to design a practical new set of embodied intensity-based benchmarks for both direct and indirect carbon emissions. Beijing, at the first level of carbon emissions trading pilot schemes in China, plays a significant role in the establishment of these schemes and is chosen as an example in this study. The newly proposed method tends to relate emissions directly to each responsibility in a practical way through the measurement of complex production and supply chains and reduce carbon emissions from their original sources. This method is expected to be developed under uncertain internal and external contexts and is further expected to be generalized to guide the establishment of industrial benchmarks for carbon emissions trading schemes in China and other countries.

  7. Energy efficiency procedures for agricultural machinery used in onion cultivation (Allium fistulosum) as an alternative to reduce carbon emissions under the clean development mechanism at Aquitania (Colombia)

    NASA Astrophysics Data System (ADS)

    Ochoa, K.; Carrillo, S.; Gutierrez, L.

    2014-06-01

    Climate change has both causes and consequences over agriculture. This paper focuses on the first element and presents scenarios for ASOLAGO -an onion cropper's association in Colombia with 250 members- to reduce their carbon footprint. It evaluates a case study at "La Primavera" farm using a methodology approved by the United Nations Framework Convention on Climate Change. Land preparation and crop irrigation were analyzed as stages in order to propose energy efficiency alternatives for both the farm and the association. They include field efficiency, fuel economy and energy efficiency from biofuels for the first stage as well as solar and wind energy supply for the second. A cost-benefit analysis to generate additional income selling additional power produced by the system to the National Grid was done.

  8. Australian climate-carbon cycle feedback reduced by soil black carbon

    NASA Astrophysics Data System (ADS)

    Lehmann, Johannes; Skjemstad, Jan; Sohi, Saran; Carter, John; Barson, Michele; Falloon, Pete; Coleman, Kevin; Woodbury, Peter; Krull, Evelyn

    2008-12-01

    Annual emissions of carbon dioxide from soil organic carbon are an order of magnitude greater than all anthropogenic carbon dioxide emissions taken together. Global warming is likely to increase the decomposition of soil organic carbon, and thus the release of carbon dioxide from soils, creating a positive feedback. Current models of global climate change that recognize this soil carbon feedback are inaccurate if a larger fraction of soil organic carbon than postulated has a very slow decomposition rate. Here we show that by including realistic stocks of black carbon in prediction models, carbon dioxide emissions are reduced by 18.3 and 24.4% in two Australian savannah regions in response to a warming of 3∘C over 100 years. This reduction in temperature sensitivity, and thus the magnitude of the positive feedback, results from the long mean residence time of black carbon, which we estimate to be approximately 1,300 and 2,600 years, respectively. The inclusion of black carbon in climate models is likely to require spatially explicit information about its distribution, given that the black carbon content of soils ranged from 0 to 82% of soil organic carbon in a continental-scale analysis of Australia. We conclude that accurate information about the distribution of black carbon in soils is important for projections of future climate change.

  9. Field Emission and Nanostructure of Carbon Films

    SciTech Connect

    Merkulov, V.I.; Lowndes, D.H.; Baylor, L.R.

    1999-11-29

    The results of field emission measurements of various forms of carbon films are reported. It is shown that the films nanostructure is a crucial factor determining the field emission properties. In particular, smooth, pulsed-laser deposited amorphous carbon films with both high and low sp3 contents are poor field emitters. This is similar to the results obtained for smooth nanocrystalline, sp2-bonded carbon films. In contrast, carbon films prepared by hot-filament chemical vapor deposition (HE-CVD) exhibit very good field emission properties, including low emission turn-on fields, high emission site density, and excellent durability. HF-CVD carbon films were found to be predominantly sp2-bonded. However, surface morphology studies show that these films are thoroughly nanostructured, which is believed to be responsible for their promising field emission properties.

  10. Fossil fuel derivatives with reduced carbon. Phase I final report

    SciTech Connect

    Kennel, E.B.; Zondlo, J.W.; Cessna, T.J.

    1999-06-30

    This project involves the simultaneous production of clean fossil fuel derivatives with reduced carbon and sulfur, along with value-added carbon nanofibers. This can be accomplished because the nanofiber production process removes carbon via a catalyzed pyrolysis reaction, which also has the effect of removing 99.9% of the sulfur, which is trapped in the nanofibers. The reaction is mildly endothermic, meaning that net energy production with real reductions in greenhouse emissions are possible. In Phase I research, the feasibility of generating clean fossil fuel derivatives with reduced carbon was demonstrated by the successful design, construction and operation of a facility capable of utilizing coal as well as natural gas as an inlet feedstock. In the case of coal, for example, reductions in CO{sub 2} emissions can be as much as 70% (normalized according to kilowatts produced), with the majority of carbon safely sequestered in the form of carbon nanofibers or coke. Both of these products are value-added commodities, indicating that low-emission coal fuel can be done at a profit rather than a loss as is the case with most clean-up schemes. The main results of this project were as follows: (1) It was shown that the nanofiber production process produces hydrogen as a byproduct. (2) The hydrogen, or hydrogen-rich hydrocarbon mixture can be consumed with net release of enthalpy. (3) The greenhouse gas emissions from both coal and natural gas are significantly reduced. Because coal consumption also creates coke, the carbon emission can be reduced by 75% per kilowatt-hour of power produced.

  11. Reducing GHG emissions in the United States' transportation sector

    SciTech Connect

    Das, Sujit; Andress, David A; Nguyen, Tien

    2011-01-01

    Reducing GHG emissions in the U.S. transportation sector requires both the use of highly efficient propulsion systems and low carbon fuels. This study compares reduction potentials that might be achieved in 2060 for several advanced options including biofuels, hybrid electric vehicles (HEV), plug-in hybrid electric vehicles (PHEV), and fuel cell electric vehicles (FCEV), assuming that technical and cost reduction targets are met and necessary fueling infrastructures are built. The study quantifies the extent of the reductions that can be achieved through increasing engine efficiency and transitioning to low-carbon fuels separately. Decarbonizing the fuels is essential for achieving large reductions in GHG emissions, and the study quantifies the reductions that can be achieved over a range of fuel carbon intensities. Although renewables will play a vital role, some combination of coal gasification with carbon capture and sequestration, and/or nuclear energy will likely be needed to enable very large reductions in carbon intensities for hydrogen and electricity. Biomass supply constraints do not allow major carbon emission reductions from biofuels alone; the value of biomass is that it can be combined with other solutions to help achieve significant results. Compared with gasoline, natural gas provides 20% reduction in GHG emissions in internal combustion engines and up to 50% reduction when used as a feedstock for producing hydrogen or electricity, making it a good transition fuel for electric propulsion drive trains. The material in this paper can be useful information to many other countries, including developing countries because of a common factor: the difficulty of finding sustainable, low-carbon, cost-competitive substitutes for petroleum fuels.

  12. Exoelectron Emission of a Carbon Nanomaterial

    NASA Astrophysics Data System (ADS)

    Kortov, V. S.; Slesarev, A. I.; Tkachev, A. G.

    2008-03-01

    The exoemission properties of a Taunite carbon nanomaterial consisting of nanosized multiwalled nanotubes and nanofibers were investigated by thermally stimulated exoelectron emission (TSEE). The TSEE spectra of the carbon nanomaterial differed from the spectra of pressed graphite. It was assumed that defect—adsorbate complexes were emission-active centers on the surface of the nanomaterial

  13. The Uncertain Carbon Emissions in China

    NASA Astrophysics Data System (ADS)

    Liu, Z.; Guan, D.; Zhang, Q.

    2014-12-01

    Anthropogenic fossil fuel emissions are considered as being well understood with a low uncertainty (9.1 ± 0.5Gt C yr-1). Yet emissions from developing countries have a higher uncertainty, and their increasing trend hence causes the global emission uncertainty to increase with time. By using full transparency emission inventory which the energy consumption, fuel heating values, carbon content and oxidation rate reported separately in sectoal level, here we found new 1.5 Gt C yr-1 (15% of global total) uncertainties of carbon emission inventory, which mainly contributed by the mass energy use and various consumption coal quality in China and India. Increment of coal's carbon emission in China and India are equivalent to 130 % of global total coal's emission growth during 2008-2010, various reported heating value and carbon content of coal consumption result in the different estimates of carbon emission in China and India up to 1.5 C yr-1. These new emerging uncertainties implies a significant mis-estimation of human induced carbon emissions and a new dominating factor in contributing the global carbon budget residual.

  14. Structuring economic incentives to reduce emissions from deforestation within Indonesia

    PubMed Central

    Busch, Jonah; Lubowski, Ruben N.; Godoy, Fabiano; Steininger, Marc; Yusuf, Arief A.; Austin, Kemen; Hewson, Jenny; Juhn, Daniel; Farid, Muhammad; Boltz, Frederick

    2012-01-01

    We estimate and map the impacts that alternative national and subnational economic incentive structures for reducing emissions from deforestation (REDD+) in Indonesia would have had on greenhouse gas emissions and national and local revenue if they had been in place from 2000 to 2005. The impact of carbon payments on deforestation is calibrated econometrically from the pattern of observed deforestation and spatial variation in the benefits and costs of converting land to agriculture over that time period. We estimate that at an international carbon price of $10/tCO2e, a “mandatory incentive structure,” such as a cap-and-trade or symmetric tax-and-subsidy program, would have reduced emissions by 163–247 MtCO2e/y (20–31% below the without-REDD+ reference scenario), while generating a programmatic budget surplus. In contrast, a “basic voluntary incentive structure” modeled after a standard payment-for-environmental-services program would have reduced emissions nationally by only 45–76 MtCO2e/y (6–9%), while generating a programmatic budget shortfall. By making four policy improvements—paying for net emission reductions at the scale of an entire district rather than site-by-site; paying for reductions relative to reference levels that match business-as-usual levels; sharing a portion of district-level revenues with the national government; and sharing a portion of the national government's responsibility for costs with districts—an “improved voluntary incentive structure” would have been nearly as effective as a mandatory incentive structure, reducing emissions by 136–207 MtCO2e/y (17–26%) and generating a programmatic budget surplus. PMID:22232665

  15. Nature of Reduced Carbon in Martian Meteorites

    NASA Technical Reports Server (NTRS)

    Gibson, Everett K., Jr.; McKay, D. S.; Thomas-Keprta, K. L.; Clemett, S. J.; White, L. M.

    2012-01-01

    Martian meteorites provide important information on the nature of reduced carbon components present on Mars throughout its history. The first in situ analyses for carbon on the surface of Mars by the Viking landers yielded disappointing results. With the recognition of Martian meteorites on Earth, investigations have shown carbon-bearing phases exist on Mars. Studies have yielded presence of reduced carbon, carbonates and inferred graphitic carbon phases. Samples ranging in age from the first approximately 4 Ga of Mars history [e.g. ALH84001] to nakhlites with a crystallization age of 1.3 Ga [e.g. Nakhla] with aqueous alteration processes occurring 0.5-0.7 Ga after crystallizaton. Shergottites demonstrate formation ages around 165-500 Ma with younger aqueous alterations events. Only a limited number of the Martian meteorites do not show evidence of significance terrestrial alterations. Selected areas within ALH84001, Nakhla, Yamato 000593 and possibly Tissint are suitable for study of their indigenous reduced carbon bearing phases. Nakhla possesses discrete, well-defined carbonaceous phases present within iddingsite alteration zones. Based upon both isotopic measurements and analysis of Nakhla's organic phases the presence of pre-terrestrial organics is now recognized. The reduced carbon-bearing phases appear to have been deposited during preterrestrial aqueous alteration events that produced clays. In addition, the microcrystalline layers of Nakhla's iddingsite have discrete units of salt crystals suggestive of evaporation processes. While we can only speculate on the origin of these unique carbonaceous structures, we note that the significance of such observations is that it may allow us to understand the role of Martian carbon as seen in the Martian meteorites with obvious implications for astrobiology and the pre-biotic evolution of Mars. In any case, our observations strongly suggest that reduced organic carbon exists as micrometer- size, discrete structures

  16. Aluminum: Reducing chloride emissions from aluminum production

    SciTech Connect

    Simon, P.

    1999-09-29

    Reynolds Metals Company (RMC), with assistance from a NICE{sup 3} grant, is developing for commercialization a closed-loop control process that greatly reduces chlorine emissions and increases plant efficiency while maintaining metal quality. The process still utilizes chlorine to remove impurities during aluminum processing, but is more effective than current methods. With the new technology chlorine in the stack is monitored and input chlorine is adjusted continuously. This optimization of chlorine use results in substantially less waste because less chlorine has to be bought or produced by aluminum manufacturers. This innovation is a significant improvement over conventional aluminum treatments, in which chlorine is injected in a more costly and wasteful manner. By the year 2010, the new technology has the potential to reduce the energy it takes to create chlorine by 8.4 billion Btu per year and to cut greenhouse gas emissions by 1,377 tons per year.

  17. Carbon adsorption on tungsten and electronic field emission

    NASA Astrophysics Data System (ADS)

    Márquez-Mijares, Maykel; Lepetit, Bruno; Lemoine, Didier

    2016-03-01

    Electronic emission taking place at the electrodes of high voltage systems and responsible for detrimental breakdown processes is known to be strongly dependent on the cathode surface state and in particular on the presence of carbon contamination. To understand better the effect of carbon adsorption on cathode electronic emission, density functional theory calculations are reported for bulk bcc tungsten as well as for clean and carbon-covered W(100) surfaces for several coverages up to 2 ML. Adsorption geometries and energies, work functions and electronic densities of states are analyzed to assess the effect of the presence of adlayers on surface electronic field emission properties. It is shown that flat carbon adlayer deposition on clean W(100) surfaces induces an increase of the surface work function and a decrease of electronic density near the Fermi level. Both factors contribute to reducing electronic field emission levels.

  18. Management practices affects soil carbon dioxide emission and carbon storage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Agricultural practices contribute about 25% of total anthropogenic carbon dioxide emission, a greenhouse gas responsible for global warming. Soil can act both as sink or source of atmospheric carbon dioxide. Carbon dioxide fixed in plant biomass through photosynthesis can be stored in soil as organi...

  19. The Uncertain Carbon Emissions in China (Invited)

    NASA Astrophysics Data System (ADS)

    Liu, Z.; Guan, D.

    2013-12-01

    Anthropogenic fossil fuel emissions are considered as being well understood with a low uncertainty (9.1 × 0.5Gt C yr-1). By using full transparency emission inventory which the energy consumption, fuel heating values, carbon content and oxidation rate reported separately in sectoal level, here we found new 2.1 Gt C yr-1 (23% of global total) uncertainties of carbon emission inventory, which mainly contributed by the mass energy use and consumption coal quality in China and by misunderstanding of fuel quality in international fossil fuel trade. Increment of coal's carbon emission in China and India are equivalent to 130 % of global total coal's emission growth during 2008-2010, by using macro energy statistics and bottom up coal mine datasets, the difference carbon emission estimates from China and India can up to 1.32 C yr-1. Emissions from international trade of coal could produce another 0.08 Gt C yr-1 uncertainty. These new emerging 1.4 Gt C yr-1 uncertainties implies a significant mis-estimation of human induced carbon emissions and a new dominating factor in contributing the global carbon budget residual.

  20. Processes for reducing NHS carbon footprint.

    PubMed

    2007-08-01

    NHS Trust boards face challenging targets for cutting carbon emissions from new and existing facilities. Spirax Sarco's Murdo Macdonald looks at the help available and some of the latest examples of good practice in steam systems for hospital heating and hot water. PMID:17847881

  1. Reducing Methyl Halide Emissions from Soils

    NASA Astrophysics Data System (ADS)

    Yates, S. R.; Xuan, R.; Ashworth, D.; Luo, L.

    2011-12-01

    Volatilization and soil transformation are major pathways by which pesticides dissipate from treated agricultural soil. Methyl bromide (MeBr) emissions from agricultural fumigation can lead to depletion of the stratospheric ozone layer. This has led to a gradual phase-out of MeBr and replacement by other halogenated chemicals. However, MeBr continues to be widely used under Critical Use Exemptions and development of emission-reduction strategies remains important. Several methods to reduce emissions of MeBr, and other halogenated soil fumigants, have been developed and are currently being tested under field conditions. In this paper, several approaches for reducing fumigant emissions to the atmosphere are described and include the use of virtually impermeable films, the creation of reactive soil barriers and a recently developed reactive film which was designed to limit loss of MeBr from soil without adding any material to the soil surface. Ammonium thiosulfate (ATS) was used to create a reactive layer. For a reactive soil layer, ATS was sprayed on the soil surface or incorporated to a depth of 1-2 cm. For the reactive film, ATS was placed between two layers of plastic film. The lower plastic layer was a high-density polyethylene film (HDPE), which is readily permeable to MeBr. The upper layer was a virtually impermeable film (VIF) and limits MeBr diffusion. MeBr diffusion and transformation through VIFs and reactive layers were tested in laboratory and field experiments. Although ineffective when dry, when sufficient water was present, reactive barriers substantially depleted halogenated fumigants, including MeBr. When ATS was activated in laboratory experiments, MeBr half-life was about 9.0 h (20C) in a reactive film barrier, and half life decreased with increasing temperature. When the soil was covered with VIF, less than 10% of the added MeBr diffused through the film and the remainder was transformed within the soil. This compares with 60 to 90% emission

  2. Retrofit methods reduce valves' fugitive emissions

    SciTech Connect

    Gallupe, W. )

    1993-06-01

    Retrofitting in-service valves is a practical alternative that reduces plant fugitive emissions and meets the federal and state environmental provisions. Plant operators must find cost-effective technologies that control and restrain valve emissions. Unfortunately, valves are dynamic devices and must move to perform their functions. Surveying all options, total replacement is not viable due to cost and scale of magnitude. However, retrofit technologies are practical measures that concentrate on correcting the problem points on a valve--the stem, the valve body and piping connections. Retrofits examine if the proper valve type is being used. Retrofit methods can meet the emission standards and reduce capital costs for environmental compliance. Leaks from nearly all types of process equipment fall under the provisions of the Clean Air Act Amendments, but valves are the most serious challenge for the process industries, and consequently, the most costly to control. The paper discusses the following: valves as dynamic devices; compliance with environmental regulations; what makes valves leak; enhanced stem sealing; modular stem sealing devices; custom design solutions; special valves; and bellows seals.

  3. Reduced Coronal Emission Above Large Isolated Sunspots

    NASA Astrophysics Data System (ADS)

    Ryabov, B. I.; Gary, D. E.; Peterova, N. G.; Shibasaki, K.; Topchilo, N. A.

    2015-01-01

    We analysed specific regions of reduced soft X-ray and microwave emission in five large isolated sunspots. The Nobeyama Radioheliograph 17 GHz observations reveal a local depression of microwave brightness in the peripheral area of the sunspots. The depression regions appear light (weak absorption) in the He 10830 Å line in areas with extended (open) field lines, as indicated by potential field source surface model (PFSS) extrapolations up to 1.5 R⊙. The observed depressions of 3 - 8 % in ordinary mode at 17 GHz are interpreted as resulting from free-free emission when the plasma density is lower by 5 - 10 %. Our model estimates show that the decrease in density in both the coronal and the lower layers above the depression region accounts for the depression. These depression regions lend themselves well to marking the location of outward plasma motions.

  4. Reduced Martian Carbon: Evidence from Martian Meteorites

    NASA Technical Reports Server (NTRS)

    Gibson, Everett K.; McKay, David S.; Thomas-Keprta, Kathie L.; Clemett, SImon J.; Pillinger, COlin T.; Wright, Ian P.; Verchovsky, A. P.

    2010-01-01

    Identification of indigenous reduced carbon species on Mars has been a challenge since the first hypotheses about life on Mars were proposed. Ranging from the early astronomical measurements to analyses of samples from the Martian surface in the form of Martian meteorites. The first direct attempt to analyze the carbon species on the surface was in 1976 with the Viking GC-MS in-situ experiment which gave inconclusive results at two sites on Mars [1]. With the recognition in 1983 that samples of the Martian surface were already present on Earth in the form of Martian meteorites by Bogard and Johnson [2] new opportunities became available for direct study of Mars's samples in te rlraesbtrioalratories. Carbon isotopic compositional information suggested a reduced carbon component was present in the Martian meteorites [3-5]. Polycyclic aromatic hydrocarbons associated with carbonate globules in ALH84001 were later identified [6,7]. Jull et al [8] noted that an insoluble component was present within Nakhla and more than 75% of its C lacked any 14C, which is modern-day carbon contaminant. This carbon fraction was believed to be either indigenous (i..e. Martian) or ancient meteoritic carbon phase. Within the fractures of Nakhla and ALH84001, Fisk et al [9,10] identified reduced carbon-enriched areas. Gibson et al. [11] using a combination of NanoSIMS, Focused Electron microscopy, Laser Raman Spectroscopy and Stepped-Combustion Static Mass Spectrometry analyses the presence of possible indigenous reduced carbon components within the 1.3 Ga old Nakhla.

  5. Reducing greenhouse gas emissions in Czechoslovakia

    SciTech Connect

    Kostalova, M.; Suk, J.; Kolar, S.

    1991-12-01

    In this paper are presented important findings on the potential for energy conservation and carbon emissions reduction over the coming decades in Czechoslovakia. The authors describe the state of the energy use in Czechoslovakia today and the measures required to transform its energy system to a market-based economy oriented towards the environmental goal of decreased energy intensity. This work furthers our understanding of the need for energy efficiency in the newly forming market economies of East and Central Europe. This paper is part of a series of country studies sponsored by the Global Climate Division of the Office of Policy, Planning, and Evaluation, United States Environmental Protection Agency (EPA). We have completed similar studies in Canada, the former Soviet Union, France, Hungary, Italy, Japan, Poland the United Kingdom, and the United States. Research is currently underway or planned in Bulgaria, Romania, and Ukraine.

  6. Direct carbon dioxide emissions from civil aircraft

    NASA Astrophysics Data System (ADS)

    Grote, Matt; Williams, Ian; Preston, John

    2014-10-01

    Global airlines consume over 5 million barrels of oil per day, and the resulting carbon dioxide (CO2) emitted by aircraft engines is of concern. This article provides a contemporary review of the literature associated with the measures available to the civil aviation industry for mitigating CO2 emissions from aircraft. The measures are addressed under two categories - policy and legal-related measures, and technological and operational measures. Results of the review are used to develop several insights into the challenges faced. The analysis shows that forecasts for strong growth in air-traffic will result in civil aviation becoming an increasingly significant contributor to anthropogenic CO2 emissions. Some mitigation-measures can be left to market-forces as the key-driver for implementation because they directly reduce airlines' fuel consumption, and their impact on reducing fuel-costs will be welcomed by the industry. Other mitigation-measures cannot be left to market-forces. Speed of implementation and stringency of these measures will not be satisfactorily resolved unattended, and the current global regulatory-framework does not provide the necessary strength of stewardship. A global regulator with ‘teeth' needs to be established, but investing such a body with the appropriate level of authority requires securing an international agreement which history would suggest is going to be very difficult. If all mitigation-measures are successfully implemented, it is still likely that traffic growth-rates will continue to out-pace emissions reduction-rates. Therefore, to achieve an overall reduction in CO2 emissions, behaviour change will be necessary to reduce demand for air-travel. However, reducing demand will be strongly resisted by all stakeholders in the industry; and the ticket price-increases necessary to induce the required reduction in traffic growth-rates place a monetary-value on CO2 emissions of approximately 7-100 times greater than other common

  7. Diamond-Coated Carbon Nanotubes for Efficient Field Emission

    NASA Technical Reports Server (NTRS)

    Dimitrijevic, Stevan; Withers, James C.

    2005-01-01

    Field-emission cathodes containing arrays of carbon nanotubes coated with diamond or diamondlike carbon (DLC) are undergoing development. Multiwalled carbon nanotubes have been shown to perform well as electron field emitters. The idea underlying the present development is that by coating carbon nanotubes with wideband- gap materials like diamond or DLC, one could reduce effective work functions, thereby reducing threshold electric-field levels for field emission of electrons and, hence, improving cathode performance. To demonstrate feasibility, experimental cathodes were fabricated by (1) covering metal bases with carbon nanotubes bound to the bases by an electrically conductive binder and (2) coating the nanotubes, variously, with diamond or DLC by plasma-assisted chemical vapor deposition. In tests, the threshold electric-field levels for emission of electrons were reduced by as much as 40 percent, relative to those of uncoated- nanotube cathodes. Coating with diamond or DLC could also make field emission-cathodes operate more stably by helping to prevent evaporation of carbon from nanotubes in the event of overheating of the cathodes. Cathodes of this type are expected to be useful principally as electron sources for cathode-ray tubes and flat-panel displays.

  8. Opportunities for reducing greenhouse gas emissions in tropical peatlands

    PubMed Central

    Murdiyarso, D.; Hergoualc’h, K.; Verchot, L. V.

    2010-01-01

    The upcoming global mechanism for reducing emissions from deforestation and forest degradation in developing countries should include and prioritize tropical peatlands. Forested tropical peatlands in Southeast Asia are rapidly being converted into production systems by introducing perennial crops for lucrative agribusiness, such as oil-palm and pulpwood plantations, causing large greenhouse gas (GHG) emissions. The Intergovernmental Panel on Climate Change Guidelines for GHG Inventory on Agriculture, Forestry, and Other Land Uses provide an adequate framework for emissions inventories in these ecosystems; however, specific emission factors are needed for more accurate and cost-effective monitoring. The emissions are governed by complex biophysical processes, such as peat decomposition and compaction, nutrient availability, soil water content, and water table level, all of which are affected by management practices. We estimate that total carbon loss from converting peat swamp forests into oil palm is 59.4 ± 10.2 Mg of CO2 per hectare per year during the first 25 y after land-use cover change, of which 61.6% arise from the peat. Of the total amount (1,486 ± 183 Mg of CO2 per hectare over 25 y), 25% are released immediately from land-clearing fire. In order to maintain high palm-oil production, nitrogen inputs through fertilizer are needed and the magnitude of the resulting increased N2O emissions compared to CO2 losses remains unclear. PMID:21081702

  9. Spatial indeterminacy and power sector carbon emissions accounting

    NASA Astrophysics Data System (ADS)

    Jiusto, J. Scott

    Carbon emission indicators are essential for understanding climate change processes, and for motivating and measuring the effectiveness of carbon reduction policy at multiple scales. Carbon indicators also play an increasingly important role in shaping cultural discourses and politics about nature-society relations and the roles of the state, markets and civil society in creating sustainable natural resource practices and just societies. The analytical and political significance of indicators is tied closely to their objective basis: how accurately they account for the places, people, and processes responsible for emissions. In the electric power sector, however, power-trading across geographic boundaries prevents a simple, purely objective spatial attribution of emissions. Using U.S. states as the unit of analysis, three alternative methods of accounting for carbon emissions from electricity use are assessed, each of which is conceptually sound and methodologically rigorous, yet produces radically different estimates of individual state emissions. Each method also implicitly embodies distinctly different incentive structures for states to enact carbon reduction policies. Because none of the three methods can be said to more accurately reflect "true" emissions levels, I argue the best method is that which most encourages states to reduce emissions. Energy and carbon policy processes are highly contested, however, and thus I examine competing interests and perspectives shaping state energy policy. I explore what it means, philosophically and politically, to predicate emissions estimates on both objectively verifiable past experience and subjectively debatable policy prescriptions for the future. Although developed here at the state scale, the issues engaged and the carbon accounting methodology proposed are directly relevant to carbon analysis and policy formation at scales ranging from the local to the international.

  10. Degassing of reduced carbon from planetary basalts

    PubMed Central

    Wetzel, Diane T.; Rutherford, Malcolm J.; Jacobsen, Steven D.; Hauri, Erik H.; Saal, Alberto E.

    2013-01-01

    Degassing of planetary interiors through surface volcanism plays an important role in the evolution of planetary bodies and atmospheres. On Earth, carbon dioxide and water are the primary volatile species in magmas. However, little is known about the speciation and degassing of carbon in magmas formed on other planets (i.e., Moon, Mars, Mercury), where the mantle oxidation state [oxygen fugacity (fO2)] is different from that of the Earth. Using experiments on a lunar basalt composition, we confirm that carbon dissolves as carbonate at an fO2 higher than -0.55 relative to the iron wustite oxygen buffer (IW-0.55), whereas at a lower fO2, we discover that carbon is present mainly as iron pentacarbonyl and in smaller amounts as methane in the melt. The transition of carbon speciation in mantle-derived melts at fO2 less than IW-0.55 is associated with a decrease in carbon solubility by a factor of 2. Thus, the fO2 controls carbon speciation and solubility in mantle-derived melts even more than previous data indicate, and the degassing of reduced carbon from Fe-rich basalts on planetary bodies would produce methane-bearing, CO-rich early atmospheres with a strong greenhouse potential. PMID:23569260

  11. Degassing of reduced carbon from planetary basalts.

    PubMed

    Wetzel, Diane T; Rutherford, Malcolm J; Jacobsen, Steven D; Hauri, Erik H; Saal, Alberto E

    2013-05-14

    Degassing of planetary interiors through surface volcanism plays an important role in the evolution of planetary bodies and atmospheres. On Earth, carbon dioxide and water are the primary volatile species in magmas. However, little is known about the speciation and degassing of carbon in magmas formed on other planets (i.e., Moon, Mars, Mercury), where the mantle oxidation state [oxygen fugacity (fO2)] is different from that of the Earth. Using experiments on a lunar basalt composition, we confirm that carbon dissolves as carbonate at an fO2 higher than -0.55 relative to the iron wustite oxygen buffer (IW-0.55), whereas at a lower fO2, we discover that carbon is present mainly as iron pentacarbonyl and in smaller amounts as methane in the melt. The transition of carbon speciation in mantle-derived melts at fO2 less than IW-0.55 is associated with a decrease in carbon solubility by a factor of 2. Thus, the fO2 controls carbon speciation and solubility in mantle-derived melts even more than previous data indicate, and the degassing of reduced carbon from Fe-rich basalts on planetary bodies would produce methane-bearing, CO-rich early atmospheres with a strong greenhouse potential. PMID:23569260

  12. The carbon dioxide emissions game: Playing the net

    SciTech Connect

    Richards, K.R.; Edmonds, J.A.; Rosenthal, D.H.; Wise, M.

    1993-06-01

    Concern about rising concentrations of carbon dioxide in the earth`s atmosphere has led to calls for the United States and other countries to reduce carbon emissions. These concerns resulted in the signing of the Framework Convention on Climate Change at the United Nations Conference on the Environment and Development in Rio de Janeiro in June 1992. The Framework calls for nations to develop action plans for limiting emissions of carbon and other greenhouse gases. In December 1992, in accordance with the Framework, the US Government released for public comment its National Action Plan for Global Climate Change (US Department of State, 1992). The Action Plan detailed steps for reducing carbon emissions by 93 to 130 million metric tons (MMT) by 2000. Some of the steps included in the Action Plan were reforming regulations, setting energy standards, promoting research and development of new energy technologies, expanding the use of alternative-fueled vehicles, and planting trees to sequester carbon. This paper explores the economic implications of implementing a much larger tree-planting program than the one presented in the Action Plan. Whereas the Action Plan estimated that 5 to 9 MMT of carbon (MMTC) could be sequestered in 2000 (with perhaps threefold increases in sequestration in later years when trees are growing the fastest), the program being considered in this analysis annually sequesters as much as 231 MMTC during its peak years. Our analysis focuses on how much the costs of stabilizing US carbon emissions at 1990 levels are reduced when economic criteria alone determine the number of trees that will be used. Our results show that when the focus is shifted from stabilization of gross emissions to net emissions the cost reductions are dramatic, about 20 to 80 percent depending on the assumed cost of trees. Political and institutional obstacles to the formation of such a cost effective response are explored in the conclusions.

  13. Feeding reduced crude protein diets with crystalline amino acids supplementation reduce air gas emissions from housing.

    PubMed

    Li, Q-F; Trottier, N; Powers, W

    2015-02-01

    The objective of this study was to test the hypothesis that reducing dietary CP by 1.5% and supplementing crystalline AA (CAA) to meet the standardized ileal digestible (SID) AA requirements for growing and finishing pigs decreases air emissions of ammonia (NH), nitrous oxide (NO), and carbon dioxide (CO) compared with an industry standard diet, without reducing growth performance. Seventy-two pigs were allocated to 12 rooms (6 pigs per room) and 2 diets (6 rooms per diet) formulated according to a 5-phase feeding program across the grow-finish period (107 d total). The diets consisted of a standard diet containing 18.5 to 12.2% CP or a reduced CP diet containing 17.5 to 11.0% CP + CAA over the course of the 5-phase feeding program. Gases (NH, NO, hydrogen sulfide, methane, nonmethane total hydrocarbon, and CO) and ventilation rates were measured continuously from the rooms. Compared with standard diet, ADG and feed conversion of pigs fed reduced CP + CAA diets did not differ (2.7 kg gain/d and 0.37 kg gain/kg feed, respectively). Compared with standard diet, feeding reduced CP + CAA diets decreased ( < 0.01) NH emissions by 46% over the 107-d period (5.4 and 2.9 g · pig · d, respectively). Change in NH emissions for each percentage unit reduction in dietary CP concentration corresponded with 47.9, 53.2, 26.8, 26.5, and 51.6% during Phases 1 through 5, respectively. Emissions of other gases did not differ between diets. Feeding reduced CP diets formulated based on SID AA requirements for grow-finisher swine is effective in reducing NH emissions from housing compared with recent industry formulations and does not impact growth performances. PMID:26020753

  14. Carbon emissions from tropical forest degradation caused by logging

    NASA Astrophysics Data System (ADS)

    Pearson, Timothy R. H.; Brown, Sandra; Casarim, Felipe M.

    2014-03-01

    The focus of land-use related efforts in developing countries to reduce carbon emissions has been on slowing deforestation, yet international agreements are to reduce emissions from both deforestation and forest degradation (REDD). The second ‘D’ is poorly understood and accounted for a number of technical and policy reasons. Here we introduce a complete accounting method for estimating emission factors from selective timber harvesting, a substantial form of forest degradation in many tropical developing countries. The method accounts separately for emissions from the extracted log, from incidental damage to the surrounding forest, and from logging infrastructure, and emissions are expressed as units of carbon per cubic meter of timber extracted to allow for simple application to timber harvesting statistics. We applied the method in six tropical countries (Belize, Bolivia, Brazil, Guyana, Indonesia, and Republic of Congo), resulting in total emission factors of 0.99-2.33 Mg C m-3. In all cases, emissions were dominated by damage to surrounding vegetation and the infrastructure rather than the logs themselves, and total emissions represented about 3-15% of the biomass carbon stocks of the associated unlogged forests. We then combined the emission factors with country level logging statistics for nine key timber producing countries represented by our study areas to gain an understanding of the order of magnitude of emissions from degradation compared to those recently reported for deforestation in the same countries. For the nine countries included, emissions from logging were on average equivalent to about 12% of those from deforestation. For those nine countries with relatively low emissions from deforestation, emissions from logging were equivalent to half or more of those from deforestation, whereas for those countries with the highest emissions from deforestation, emissions from logging were equivalent to <10% of those from deforestation. Understanding how

  15. Possibilities to reduce carbon emissions in Brazilian Amazon region with non timber biomass valorization: The case of biofuels produced by vegetable tropical oils

    SciTech Connect

    Freitas, M.A.V. de; Rosa, L.P.; Lascio, M.A. Di |

    1996-12-31

    Brazil`s annual rate of deforestation reached 2.1 million ha or about 13.6% of the total annual rate of deforestation for the whole tropical area in the world during 1981--1990. Today, the extent of gross deforestation is 10.9% of the tropical closed forest area. Relative to Brazilian participation in the greenhouse effect, the changes in forest area and associated biomass burning in Amazon region are responsible for about 25.5% of CO{sub 2} emissions in the tropics. Harvest of the non-timber biomass products may be important as a potentially sustainable use of forest in some areas. An excellent option to promote these biomass products is to provide energy and industrial goods for the Amazon communities and other external markets. In this work, the biofuels produced by vegetable tropical oils and their by-products are analyzed in relation to job creation, economics and environmental impacts, with special regards concerning the limitation of the atmospheric emissions of greenhouse gases.

  16. Coping with carbon: a near-term strategy to limit carbon dioxide emissions from power stations.

    PubMed

    Breeze, Paul

    2008-11-13

    Burning coal to generate electricity is one of the key sources of atmospheric carbon dioxide emissions; so, targeting coal-fired power plants offers one of the easiest ways of reducing global carbon emissions. Given that the world's largest economies all rely heavily on coal for electricity production, eliminating coal combustion is not an option. Indeed, coal consumption is likely to increase over the next 20-30 years. However, the introduction of more efficient steam cycles will improve the emission performance of these plants over the short term. To achieve a reduction in carbon emissions from coal-fired plant, however, it will be necessary to develop and introduce carbon capture and sequestration technologies. Given adequate investment, these technologies should be capable of commercial development by ca 2020. PMID:18757277

  17. Reducing VOC Press Emission from OSB Manufacturing

    SciTech Connect

    Dr. Gary D. McGinnis; Laura S. WIlliams; Amy E. Monte; Jagdish Rughani: Brett A. Niemi; Thomas M. Flicker

    2001-12-31

    Current regulations require industry to meet air emission standards with regard to particulates, volatile organic compounds (VOCs), hazardous air pollutants (HAPs) and other gases. One of many industries that will be affected by the new regulations is the wood composites industry. This industry generates VOCs, HAPs, and particulates mainly during the drying and pressing of wood. Current air treatment technologies for the industry are expensive to install and operate. As regulations become more stringent, treatment technologies will need to become more efficient and cost effective. The overall objective of this study is to evaluate the use of process conditions and chemical additives to reduce VOC/HAPs in air emitted from presses and dryers during the production of oriented strand board.

  18. Carbon storage in the deep reducing mantle

    NASA Astrophysics Data System (ADS)

    Rohrbach, A.; Ghosh, S.; Schmidt, M. W.; Wijbrans, C. H.; Klemme, S.

    2014-12-01

    To understand the storage and cycling of carbon in/through Earth's deep mantle it is vital to examine carbon speciations at relevant pressure, temperature, and oxygen fugacity (fO2). In particular redox conditions of the mantle critically influence the mobility of carbon bearing phases in the silicate matrix; oxidized species are generally more mobile (carbonatites, carbonated silicate melts) or have a larger impact on silicate solidi (carbonated peridotite/eclogite) than reduced species (diamond, carbides, metals). Within garnet bearing mantle lithologies, fO2 can be expected to decrease with depth [1], eventually reaching values similar to the iron-wüstite equilibrium which implies the precipitation of a Fe-Ni metal phase at pressures corresponding to the base of the upper mantle [2]. Because Ni is more noble than Fe, Ni partitions strongly into the reduced phases such that at low metal fractions the metal phase reaches XNi > 0.5. Thermodynamic calculations suggest that the mantle contains ~0.1 wt.% Fe,Ni metal at ~300 km depth [3], increasing to ~1 wt% in the lower mantle [4]. To understand the nature of carbon bearing reduced phases in the Earth mantle, we examine experimentally phase relations and melting behavior in the system Fe-Ni-C at 10 and 23 GPa. Dependent on Fe-Ni ratio and related fO2, C content, P and T we observe a variety of phases, namely (Fe,Ni)3C and (Fe,Ni)7C3 carbides, carbon bearing Fe-Ni metal, diamond and carbon rich metal-melt. In the subsolidus, mantle bulk C contents of 50 to 500 ppm [5] would result in the phase association (Fe,Ni)3C + metal + diamond at 10 GPa. In the uppermost lower mantle, about 1 wt.% metal would dissolve ca. 100 ppm C, any further C would lead to (Fe,Ni)3C carbide saturation. The solidus temperatures of theses phase assemblages however are considerably lower than the geotherm at upper and lower mantle pressures. We therefore suggest that reduced carbon bearing phases in the deep mantle are largely molten [6]. [1

  19. Allowable carbon emissions lowered by multiple climate targets.

    PubMed

    Steinacher, Marco; Joos, Fortunat; Stocker, Thomas F

    2013-07-11

    Climate targets are designed to inform policies that would limit the magnitude and impacts of climate change caused by anthropogenic emissions of greenhouse gases and other substances. The target that is currently recognized by most world governments places a limit of two degrees Celsius on the global mean warming since preindustrial times. This would require large sustained reductions in carbon dioxide emissions during the twenty-first century and beyond. Such a global temperature target, however, is not sufficient to control many other quantities, such as transient sea level rise, ocean acidification and net primary production on land. Here, using an Earth system model of intermediate complexity (EMIC) in an observation-informed Bayesian approach, we show that allowable carbon emissions are substantially reduced when multiple climate targets are set. We take into account uncertainties in physical and carbon cycle model parameters, radiative efficiencies, climate sensitivity and carbon cycle feedbacks along with a large set of observational constraints. Within this framework, we explore a broad range of economically feasible greenhouse gas scenarios from the integrated assessment community to determine the likelihood of meeting a combination of specific global and regional targets under various assumptions. For any given likelihood of meeting a set of such targets, the allowable cumulative emissions are greatly reduced from those inferred from the temperature target alone. Therefore, temperature targets alone are unable to comprehensively limit the risks from anthropogenic emissions. PMID:23823728

  20. Managing Restored Wetlands in the Sacramento-San Joaquin Delta to Reduce Methane Emissions and Increase Carbon Uptake Laurie Koteen, Sara Knox, Cove Sturtevant, Joseph Verfaillie, Jaclyn Hatala, Dennis Baldocchi

    NASA Astrophysics Data System (ADS)

    Koteen, L. E.; Knox, S. H.; Sturtevant, C. S.; Verfaillie, J. G.; Matthes, J. H.; Baldocchi, D. D.

    2013-12-01

    The Sacramento-San Joaquin Delta of California is a region transformed by more than a century of agricultural practices. Beginning in the 19th century, substantial regions were first drained of water and then converted to cropland in order to take advantage of the area's rich peatland soils. In the intervening time period, soil oxidation and subsidence have led to huge peat losses of up to 10 m in some places, and river water now threatens to topple the levees that were erected to keep fields from flooding. Within this region, we have been monitoring greenhouse gas exchange of several agricultural sites, a degraded pasture, and two restored wetlands. Of these land use types, restoration of wetlands is of particular interest to Delta managers as these sites attain many of the region's most pressing ecological goals, including improved water quality, increased wildlife habitat, and soil accretion. In our current investigation, we hope to assess if wetland management activities can be implemented to achieve greenhouse gas management goals as well. While we find that the restored wetlands are able to take up and store a substantial amount of carbon via rapid growth rates, they also emit methane; a greenhouse gas 25 times more potent than CO¬2. We are currently in the process of implementing two management activities with the goals of reducing methane emissions and increasing carbon uptake. Evidence from the wetland literature indicates that periodic lowering of the water table below the soil surface can reduce wetland methane emissions by: 1. Reintroducing oxygen into the soil column. This both supports growth of the methanotrophic bacteria that consume methane produced in the anaerobic zones of the soil column, and suppresses the methanogens that produce it. 2. Re-oxidization of formerly reduced compounds in the soil, (i.e. NO3-, SO42-) which can serve as alternative terminal electron acceptors of the decomposition byproducts (i.e. H2 and acetate) that lead to

  1. The Megacities Carbon Project: measuring urban carbon emissions

    NASA Astrophysics Data System (ADS)

    Duren, R. M.; Kort, E. A.; Miller, C. E.

    2012-12-01

    Carbon emissions from cities represent the single largest human contribution to climate change. Robust verification of emission changes due to growth or stabilization policies requires that we establish measurement baselines today and begin monitoring representative megacities immediately. An observing system designed to monitor the localized enhancements ("urban domes") of carbon dioxide and methane associated with cities must include a tiered set of surface, airborne, and satellite sensors and a framework for integrating top-down (atmospheric) and bottom-up (activity) data. We present a vision, strategy, requirements, and roadmap for an international effort to assess directly the carbon emission trends of the world's megacities. We describe a new coordinated pilot project for the megacities of Los Angeles and Paris that leverages and extends established measurement infrastructure in those cities and techniques being developed in methodological studies of smaller cities.

  2. Grid Expansion Planning for Carbon Emissions Reduction

    SciTech Connect

    Bent, Russell W.; Toole, Gasper L.

    2012-07-18

    There is a need to upgrade and expand electric power transmission and generation to meet specified renewable energy targets and simultaneously minimize construction cost and carbon emissions. Some challenges are: (1) Renewable energy sources have variable production capacity; (2) Deficiency of transmission capacity at desirable renewable generation locations; (3) Need to incorporate models of operations into planning studies; and (4) Prevent undesirable operational outcomes such as negative dispatch prices or curtailment of carbon neutral generation.

  3. On-site denitrification beds could reduce indirect greenhouse gas emissions from agricultural drainage waters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nitrate (NO3-) laden agricultural drainage waters are non-point sources of indirect nitrous oxide (N2O) emissions, which represent a significant fraction of total N2O emissions in the USA. On-site denitrification beds filled with woodchips were used to reduce NO3- under carbon rich anaerobic conditi...

  4. Method for reducing CO and HC emissions

    SciTech Connect

    Baron, K.; Hegedus, L.; Oh, S.H.

    1980-09-16

    A method is described for decreasing CO and HC emissions in a vehicle exhaust stream during the period of engine warm-up following the start of engine operation, in which the A/F mixture to the engine is pulsed by first using a mixture which is leaner than that otherwise used thus reducing the CO and HC content of the exhaust stream exiting the engine to an amount below that of the CO and HC otherwise present and then using an A/F mixture which is richer than such lean mixture and is substantially that otherwise used thus increasing the amount of CO and HC in the vehicle exhaust stream to substantially the amount otherwise present, passing the pulsed exhaust stream through a catalytic converter adapted to oxidize the CO and HC constituents, and repeating this pulsing continuously through the period of engine warm-up and at a rate sufficient to achieve increased catalytic conversion of CO and HC over that obtained without pulsing, the rate being also sufficiently rapid so as to preclude engine-stall. A preferred system for practicing the method involves apparatus for the repeated opening of the choke plate of the engine carburetor during the period when the choke plate is not full-open.

  5. Mid infrared emission spectroscopy of carbon plasma.

    PubMed

    Nemes, Laszlo; Brown, Ei Ei; S-C Yang, Clayton; Hommerich, Uwe

    2017-01-01

    Mid infrared time-resolved emission spectra were recorded from laser-induced carbon plasma. These spectra constitute the first study of carbon materials LIB spectroscopy in the mid infrared range. The carbon plasma was induced using a Q-switched Nd: YAG laser. The laser beam was focused to high purity graphite pellets mounted on a translation stage. Mid infrared emission from the plasma in an atmospheric pressure background gas was detected by a cooled HgCdTe detector in the range 4.4-11.6μm, using long-pass filters. LIB spectra were taken in argon, helium and also in air. Despite a gate delay of 10μs was used there were strong backgrounds in the spectra. Superimposed on this background broad and noisy emission bands were observed, the form and position of which depended somewhat on the ambient gas. The spectra were digitally smoothed and background corrected. In argon, for instance, strong bands were observed around 4.8, 6.0 and 7.5μm. Using atomic spectral data by NIST it could be concluded that carbon, argon, helium and nitrogen lines from neutral and ionized atoms are very weak in this spectral region. The width of the infrared bands supports molecular origin. The infrared emission bands were thus compared to vibrational features of carbon molecules (excluding C2) of various sizes on the basis of previous carbon cluster infrared absorption and emission spectroscopic analyses in the literature and quantum chemical calculations. Some general considerations are given about the present results. PMID:27428600

  6. Foliar temperature acclimation reduces simulated carbon sensitivity to climate

    NASA Astrophysics Data System (ADS)

    Smith, Nicholas G.; Malyshev, Sergey L.; Shevliakova, Elena; Kattge, Jens; Dukes, Jeffrey S.

    2016-04-01

    Plant photosynthesis and respiration are the largest carbon fluxes between the terrestrial biosphere and the atmosphere, and their parameterizations represent large sources of uncertainty in projections of land carbon uptake in Earth system models (ESMs). The incorporation of temperature acclimation of photosynthesis and foliar respiration, commonly observed processes, into ESMs has been proposed as a way to reduce this uncertainty. Here we show that, across 15 flux tower sites spanning multiple biomes at various locations worldwide (10° S-67° N), acclimation parameterizations improve a model's ability to reproduce observed net ecosystem exchange of CO2. This improvement is most notable in tropical biomes, where photosynthetic acclimation increased model performance by 36%. The consequences of acclimation for simulated terrestrial carbon uptake depend on the process, region and time period evaluated. Globally, including acclimation has a net effect of increasing carbon assimilation and storage, an effect that diminishes with time, but persists well into the future. Our results suggest that land models omitting foliar temperature acclimation are likely to overestimate the temperature sensitivity of terrestrial carbon exchange, thus biasing projections of future carbon storage and estimates of policy indicators such as the transient climate response to cumulative carbon emissions.

  7. Emission of reduced malodorous sulfur gases from wastewater treatment plants

    SciTech Connect

    Devai, I.; DeLaune, R.D.

    1999-03-01

    The emission of malodorous gaseous compounds from wastewater collection and treatment facilities is a growing maintenance and environmental problem. Numerous gaseous compounds with low odor detection thresholds are emitted from these facilities. Sulfur-bearing gases represent compounds with the lowest odor detection threshold. Using solid adsorbent preconcentration and gas chromatographic methods, the quantity and composition of reduced malodorous sulfur gases emitted from various steps of the treatment process were determined in wastewater treatment plants in Baton Rouge, Louisiana. Hydrogen sulfide, which is a malodorous, corrosive, and potentially toxic gas, was the most dominant volatile reduced sulfur (S) compound measured. Concentrations were not only more than the odor detection threshold of hydrogen sulfide, but above levels that may affect health during long-term exposure. The concentrations of methanethiol, dimethyl sulfide, carbon disulfide, and carbonyl sulfide were significantly less than hydrogen sulfide. However, even though emissions of reduced sulfur gases other than hydrogen sulfide were low, previous studies suggested that long-term exposure to such levels may cause respiratory problems and other symptoms.

  8. A study on the impact of nuclear power plant construction relative to decommissioning Fossil Fuel Power Plant in order to reduce carbon dioxide emissions using a modified Nordhaus Vensim DICE model

    NASA Astrophysics Data System (ADS)

    Colpetzer, Jason Lee

    The current levels of CO2 emissions and high levels accumulating in the atmosphere have climate scientists concerned. The Dynamic Integrated Climate Economy Model or "DICE" for short is a highly developed model that has been used to simulate climate change and evaluate factors addressing global warming. The model was developed by Yale's Nordhaus along with collaborators and the compilation of numerous scientific publications. The purpose of this study is to recreate DICE using Vensim and modify it to evaluate the use of nuclear power plants (NPPs) as a means to counter global temperature increases in the atmosphere and oceans and the associated cost of damages. The amount of greenhouse gas emissions from a NPP are about 6% per Megawatt as that from a Fossil Fuel Power Plant (FFPP). Based on this, a model was developed to simulate construction of NPPs with subsequent decommissioning of FFPPs with an equivalent power output. The results produced through multiple simulation runs utilizing variable NPP construction rates show that some minor benefit is achievable if all of the more than 10,000 FFPPs currently in operation in the U.S. are replaced with NPPs. The results show that a reduction in CO 2 emissions of 2.48% will occur if all of the FFPPs are decommissioned. At a minimum rate of 50 NPPs constructed per year, the largest reduction in CO2 in the atmosphere, 1.94% or 44.5 billion tons of carbon, is possible. This results in a reduction in global warming of 0.068°C or 1.31%. The results also show that this reduction in global warming will be equivalent to a reduction of 8.2% or $148 B in anticipated annual spending as a result of climate change damages. Further results indicate that using NPPs to address climate change will provide a small benefit; ultimately, it will not be enough to reduce CO2 emissions or atmospheric CO 2 to control global warming. The amount of CO2 in the atmosphere is predicted to be 1055 parts per million (ppm) even in the best case

  9. Carbon footprint and ammonia emissions of California beef production systems.

    PubMed

    Stackhouse-Lawson, K R; Rotz, C A; Oltjen, J W; Mitloehner, F M

    2012-12-01

    Beef production is a recognized source of greenhouse gas (GHG) and ammonia (NH(3)) emissions; however, little information exists on the net emissions from beef production systems. A partial life cycle assessment (LCA) was conducted using the Integrated Farm System Model (IFSM) to estimate GHG and NH(3) emissions from representative beef production systems in California. The IFSM is a process-level farm model that simulates crop growth, feed production and use, animal growth, and the return of manure nutrients back to the land to predict the environmental impacts and economics of production systems. Ammonia emissions are determined by summing the emissions from animal housing facilities, manure storage, field applied manure, and direct deposits of manure on pasture and rangeland. All important sources and sinks of methane, nitrous oxide, and carbon dioxide are predicted from primary and secondary emission sources. Primary sources include enteric fermentation, manure, cropland used in feed production, and fuel combustion. Secondary emissions occur during the production of resources used on the farm, which include fuel, electricity, machinery, fertilizer, and purchased animals. The carbon footprint is the net exchange of all GHG in carbon dioxide equivalent (CO(2)e) units per kg of HCW produced. Simulated beef production systems included cow-calf, stocker, and feedlot phases for the traditional British beef breeds and calf ranch and feedlot phases for Holstein steers. An evaluation of differing production management strategies resulted in ammonia emissions ranging from 98 ± 13 to 141 ± 27 g/kg HCW and carbon footprints of 10.7 ± 1.4 to 22.6 ± 2.0 kg CO(2)e/kg HCW. Within the British beef production cycle, the cow-calf phase was responsible for 69 to 72% of total GHG emissions with 17 to 27% from feedlot sources. Holstein steers that entered the beef production system as a by-product of dairy production had the lowest carbon footprint because the emissions

  10. A performance standards approach to reducing CO{sub 2} emissions from electric power plants

    SciTech Connect

    Rubin, E.S.

    2009-06-15

    The CO{sub 2} emission performance standard policies outlined in this paper could complement a cap-and-trade program that puts a price on carbon and serve to significantly reduce the CO{sub 2} emissions from coal use for electricity generation. Emission performance standards have a long history in the United States and have been successfully used to control emissions of various air pollutants from electric generators. This paper explores the rationale for using emission performance standards and describes the various types of performance standard policies. Emission performance standards that address CO{sub 2} emissions could promote the deployment of carbon capture and storage technology coupled with new and existing coal-fueled electric power plants. 28 refs., 4 figs., 4 tabs.

  11. Characterizing the carbon emissions of megacities

    NASA Astrophysics Data System (ADS)

    Duren, R. M.; Gurney, K. R.; Hutyra, L.; Miller, C. E.; Kort, E. A.; Rao, P.; Eldering, A.

    2014-12-01

    Anthropogenic carbon emissions from cities and their power plants represent the single largest human contribution to climate change. Many cities with large fossil-fuel CO2 and CH4 fluxes are undergoing rapid change due to development, urbanization, energy sector transformations and/or climate mitigation actions. Meanwhile, flux estimation uncertainties at these finer spatial scales remain significantly larger than those at the continental and national scales addressed by traditional carbon estimation techniques. Improved quantification and understanding of underlying processes at the urban scale will not only provide policy-relevant information and improve the understanding of urban dynamics and future scenarios, but will translate into better global-scale anthropogenic flux estimates, and advance our understanding of carbon cycle and climate feedbacks across multiple scales. An observing system including a tiered set of surface, airborne, and satellite sensors combined with process-based flux quantification from the bottom-up, can be focused spatially and sectorally to address these challenges. A thoughtfully crafted research program that is grounded in sustained, dense observations relevant to estimating urban carbon fluxes and their controlling processes and is focused on a statistically significant sample of cities will advance our understanding of the carbon cycle. We describe the Megacities Carbon Project as an example for developing and validating the integrated application of atmospheric observations from localized surface networks, aircraft campaigns, and satellites with an analytical construct for linking atmospheric information with the human activities that drive emissions.

  12. End-Use Efficiency to Lower Carbon Emissions

    SciTech Connect

    Marnay, Chris; Osborn, Julie; Webber, Carrie

    2001-03-01

    Compelling evidence demonstrating the warming trend in global temperatures and the mechanism behind it, namely the anthropogenic emissions of carbon dioxide and other greenhouse gases (GHG), has spurred an international effort to reduce emissions of these gases. Despite improving efficiency of the U.S. economy in terms of energy cost per dollar of GDP since the signing of the Kyoto Protocol, energy consumption and carbon emissions are continuing to rise as the economy expands. This growing gap further emphasizes the importance of improving energy use efficiency as a component in the U.S. climate change mitigation program. The end-use efficiency research activities at Berkeley Lab incorporate residential, commercial, industrial, and transportation sectors. This paper focuses on two successful U.S. programs that address end-use efficiency in residential and commercial demand: energy efficient performance standards established by the Department of Energy (DOE) and the Environmental Protection Agency's (EPA's) ENERGY STAR(registered trademark) program.

  13. An approach to a black carbon emission inventory for Mexico by two methods.

    PubMed

    Cruz-Núñez, Xochitl

    2014-05-01

    A black carbon (BC) emission inventory for Mexico is presented. Estimate was performed by using two approaches, based on fuel consumption and emission factors in a top-down scheme, and the second from PM25 emission data and its correlation with black carbon by source category, assuming that black carbon=elemental carbon. Results show that black carbon emissions are in interval 53-473Gg using the fuel consumption approach and between 62 and 89 using the sector method. Black carbon key sources come from biomass burning in the rural sector, with 47 percent share to the National total. Mobile sources emissions account to 16% to the total. An opportunity to reduce, in the short-term, carbon dioxide equivalent (CO2-eq) emissions by reducing black carbon emissions would be obtained in reducing emissions mainly from biomass burning in rural housing sector and diesel emissions in the transport sector with important co-benefits in direct radiative forcing, public health and air quality. PMID:24561296

  14. Global civil aviation black carbon emissions.

    PubMed

    Stettler, Marc E J; Boies, Adam M; Petzold, Andreas; Barrett, Steven R H

    2013-09-17

    Aircraft black carbon (BC) emissions contribute to climate forcing, but few estimates of BC emitted by aircraft at cruise exist. For the majority of aircraft engines the only BC-related measurement available is smoke number (SN)-a filter based optical method designed to measure near-ground plume visibility, not mass. While the first order approximation (FOA3) technique has been developed to estimate BC mass emissions normalized by fuel burn [EI(BC)] from SN, it is shown that it underestimates EI(BC) by >90% in 35% of directly measured cases (R(2) = -0.10). As there are no plans to measure BC emissions from all existing certified engines-which will be in service for several decades-it is necessary to estimate EI(BC) for existing aircraft on the ground and at cruise. An alternative method, called FOX, that is independent of the SN is developed to estimate BC emissions. Estimates of EI(BC) at ground level are significantly improved (R(2) = 0.68), whereas estimates at cruise are within 30% of measurements. Implementing this approach for global civil aviation estimated aircraft BC emissions are revised upward by a factor of ~3. Direct radiative forcing (RF) due to aviation BC emissions is estimated to be ~9.5 mW/m(2), equivalent to ~1/3 of the current RF due to aviation CO2 emissions. PMID:23844612

  15. The Land Use Planning Imperative: Applying Carbon Emissions Analyses

    NASA Astrophysics Data System (ADS)

    Bray, E. N.; Havens, G.

    2007-12-01

    Reversing global warming is the defining crisis of the 21st century and must be dealt with, in part, by reinventing the built environment. Current land use and planning frameworks are not aligned with scientific models which can aid in the reversal of carbon emissions at the local and regional scale. The disjunction between land use planning and the scientific methodologies for calculating the impacts of climate change beg for a stronger union between climate change science and land use planning. Buildings account for approximately 35 percent of the U.S. carbon emissions while the transportation sector accounts for approximately 27 percent (U.S. Department of Energy, Energy Information Administration, United States Environmental Protection Agency, 2007). To adopt energy efficiency measures and hence reduce carbon dioxide emissions at a site, city, or regional scale, land use planners and climate scientists must integrate their expertise to influence policy with precision and accuracy. Land use planners have influence over the design of the built environment in municipalities and institutions such as colleges and universities. In many ways, college and university campuses are microcosms of the land use patterns established historically; they demonstrate a lack of coordinated land use planning across the entire continent that is extremely dependent on the automobile and fossil fuels. Climate models predict that the average temperature at the Earth's surface could increase from 2.5 to 10.4ºF above 1990 levels by the end of this century (United States Environmental Protection Agency, 2007). Further, it is estimated that the country will have to construct an additional 213 billion square feet of built space by the year 2030 to accommodate the increasing population. Planning and design will dictate the degree to which land use change will exacerbate trends of global warming. It commands an integration of the methodology to calculate carbon emissions with the science

  16. Black carbon emissions reductions from combustion of alternative jet fuels

    NASA Astrophysics Data System (ADS)

    Speth, Raymond L.; Rojo, Carolina; Malina, Robert; Barrett, Steven R. H.

    2015-03-01

    Recent measurement campaigns for alternative aviation fuels indicate that black carbon emissions from gas turbines are reduced significantly with the use of alternative jet fuels that are low in aromatic content. This could have significant climate and air quality-related benefits that are currently not accounted for in environmental assessments of alternative jet fuels. There is currently no predictive way of estimating aircraft black carbon emissions given an alternative jet fuel. We examine the results from available measurement campaigns and propose a first analytical approximation (termed 'ASAF') of the black carbon emissions reduction associated with the use of paraffinic alternative jet fuels. We establish a relationship between the reduction in black carbon emissions relative to conventional jet fuel for a given aircraft, thrust setting relative to maximum rated thrust, and the aromatic volume fraction of the (blended) alternative fuel. The proposed relationship is constrained to produce physically meaningful results, makes use of only one free parameter and is found to explain a majority of the variability in measurements across the engines and fuels that have been tested.

  17. A Healthy Reduction in Oil Dependence and Carbon Emissions

    NASA Astrophysics Data System (ADS)

    Higgins, P. A.; Higgins, M.

    2003-12-01

    Societal dependence on oil as an energy source for personal transportation leads to increasingly negative social consequences including climate change, air pollution, political and economic instability and habitat degradation. Our heavy reliance on the automobile for transportation, determined in part by urban sprawl, also contributes to the population's increasingly sedentary lifestyle and to a concomitant degradation in health. We have shown that widespread substitution of exercise, commensurate with previously recommended levels, through biking or walking instead of driving can substantially reduce oil consumption and carbon emissions. For example, if all individuals between the ages of 10 and 64 substituted one hour of cycling for driving the reduction in gasoline demand would be equivalent to the gas produced from 34.9 percent of current oil consumption. Relative to 1990 net US emissions, this constitutes a 10.9 percent reduction in carbon emissions. Therefore, substitution of exercise for driving could improve health, reduce carbon emissions and save more oil than even upper estimates of that contained in the Arctic National Wildlife Refuge.

  18. Tracing fuel component carbon in the emissions from diesel engines

    NASA Astrophysics Data System (ADS)

    Buchholz, Bruce A.; Mueller, Charles J.; Martin, Glen C.; Cheng, A. S.; Dibble, Robert W.; Frantz, Brian R.

    2004-08-01

    The addition of oxygenates to diesel fuel can reduce particulate emissions, but the underlying chemical pathways for the reductions are not well understood. While measurements of particulate matter (PM), unburned hydrocarbons (HC), and carbon monoxide (CO) are routine, determining the contribution of carbon atoms in the original fuel molecules to the formation of these undesired exhaust emissions has proven difficult. Renewable bio-derived fuels (ethanol or bio-diesel) containing a universal distribution of contemporary carbon are easily traced by accelerator mass spectrometry (AMS). These measurements provide general information about the emissions of bio-derived fuels. Another approach exploits synthetic organic chemistry to place 14C atoms in a specific bond position in a specific fuel molecule. The highly labeled fuel molecule is then diluted in 14C-free petroleum-derived stock to make a contemporary petroleum fuel suitable for tracing. The specific 14C atoms are then traced through the combustion event to determine whether they reside in PM, HC, CO, CO2, or other emission products. This knowledge of how specific molecular structures produce certain emissions can be used to refine chemical-kinetic combustion models and to optimize fuel composition to reduce undesired emissions. Due to the high sensitivity of the technique and the lack of appreciable 14C in fossil fuels, fuels for AMS experiments can be labeled with modern levels of 14C and still produce a strong signal. Since the fuel is not radioactive, emission tests can be conducted in any conventional engine lab, dynamometer facility, or on the open road.

  19. Tracing Fuel Component Carbon in the Emissions from Diesel Engines

    SciTech Connect

    Buchholz, B A; Mueller, C J; Martin, G C; Cheng, A S E; Dibble, R W; Frantz, B R

    2002-10-14

    The addition of oxygenates to diesel fuel can reduce particulate emissions, but the underlying chemical pathways for the reductions are not well understood. While measurements of particulate matter (PM), unburned hydrocarbons (HC), and carbon monoxide (CO) are routine, determining the contribution of carbon atoms in the original fuel molecules to the formation of these undesired exhaust emissions has proven difficult. Renewable bio-derived fuels (ethanol or bio-diesel) containing a universal distribution of contemporary carbon are easily traced by accelerator mass spectrometry (AMS). These measurements provide general information about the emissions of bio-derived fuels. Another approach exploits synthetic organic chemistry to place {sup 14}C atoms in a specific bond position in a specific fuel molecule. The highly labeled fuel molecule is then diluted in {sup 14}C-free petroleum-derived stock to make a contemporary petroleum fuel suitable for tracing. The specific {sup 14}C atoms are then traced through the combustion event to determine whether they reside in PM, HC, CO, CO{sub 2}, or other emission products. This knowledge of how specific molecular structures produce certain emissions can be used to refine chemical-kinetic combustion models and to optimize fuel composition to reduce undesired emissions. Due to the high sensitivity of the technique and the lack of appreciable {sup 14}C in fossil fuels, fuels for AMS experiments can be labeled with modern levels of {sup 14}C and still produce a strong signal. Since the fuel is not radioactive, emission tests can be conducted in any conventional engine lab, dynamometer facility, or on the open road.

  20. Implementation of Emission Trading in Carbon Dioxide Sequestration Optimization Management

    NASA Astrophysics Data System (ADS)

    Zhang, X.; Duncan, I.

    2013-12-01

    As an effective mid- and long- term solution for large-scale mitigation of industrial CO2 emissions, CO2 capture and sequestration (CCS) has been paid more and more attention in the past decades. A general CCS management system has complex characteristics of multiple emission sources, multiple mitigation technologies, multiple sequestration sites, and multiple project periods. Trade-off exists among numerous environmental, economic, political, and technical factors, leading to varied system features. Sound decision alternatives are thus desired for provide decision supports for decision makers or managers for managing such a CCS system from capture to the final geologic storage phases. Carbon emission trading has been developed as a cost-effective tool for reducing the global greenhouse gas emissions. In this study, a carbon capture and sequestration optimization management model is proposed to address the above issues. The carbon emission trading is integrated into the model, and its impacts on the resulting management decisions are analyzed. A multi-source multi-period case study is provided to justify the applicability of the modeling approach, where uncertainties in modeling parameters are also dealt with.

  1. Predator-induced reduction of freshwater carbon dioxide emissions

    NASA Astrophysics Data System (ADS)

    Atwood, Trisha B.; Hammill, Edd; Greig, Hamish S.; Kratina, Pavel; Shurin, Jonathan B.; Srivastava, Diane S.; Richardson, John S.

    2013-03-01

    Predators can influence the exchange of carbon dioxide between ecosystems and the atmosphere by altering ecosystem processes such as decomposition and primary production, according to food web theory. Empirical knowledge of such an effect in freshwater systems is limited, but it has been suggested that predators in odd-numbered food chains suppress freshwater carbon dioxide emissions, and predators in even-numbered food chains enhance emissions. Here, we report experiments in three-tier food chains in experimental ponds, streams and bromeliads in Canada and Costa Rica in the presence or absence of fish (Gasterosteus aculeatus) and invertebrate (Hesperoperla pacifica and Mecistogaster modesta) predators. We monitored carbon dioxide fluxes along with prey and primary producer biomass. We found substantially reduced carbon dioxide emissions in the presence of predators in all systems, despite differences in predator type, hydrology, climatic region, ecological zone and level of in situ primary production. We also observed lower amounts of prey biomass and higher amounts of algal and detrital biomass in the presence of predators. We conclude that predators have the potential to markedly influence carbon dioxide dynamics in freshwater systems.

  2. REDUCING STYRENE EMISSIONS FROM SPRAYED FILLED RESINS

    EPA Science Inventory

    Styrene emissions are coming under increasing study as the U.S. Environmental Protection Agency (EPA) develops maximum achievable control technology standards. During the manufacture of fiber-reinforced plastics/composites products, styrene, a volatile organic compound and a haz...

  3. Earth system responses to cumulative carbon emissions

    NASA Astrophysics Data System (ADS)

    Steinacher, M.; Joos, F.

    2015-07-01

    Information on the relationship between cumulative fossil carbon emissions and multiple climate targets are essential to design emission mitigation and climate adaptation strategies. In this study, the transient responses in different climate variables are quantified for a large set of multi-forcing scenarios extended to year 2300 towards stabilization and in idealized experiments using the Bern3D-LPJ carbon-climate model. The model outcomes are constrained by 26 physical and biogeochemical observational data sets in a Bayesian, Monte-Carlo type framework. Cumulative fossil emissions of 1000 Gt C result in a global mean surface air temperature change of 1.88 °C (68 % confidence interval (c.i.): 1.28 to 2.69 °C), a decrease in surface ocean pH of 0.19 (0.18 to 0.22), and in steric sea level rise of 20 cm (13 to 27 cm until 2300). Linearity between cumulative emissions and transient response is high for pH and reasonably high for surface air and sea surface temperatures, but less pronounced for changes in Atlantic Meridional Overturning, Southern Ocean and tropical surface water saturation with respect to biogenic structures of calcium carbonate, and carbon stocks in soils. The slopes of the relationships change when CO2 is stabilized. The Transient Climate Response is constrained, primarily by long-term ocean heat observations, to 1.7 °C (68 % c.i.: 1.3 to 2.2 °C) and the Equilibrium Climate Sensitivity to 2.9 °C (2.0 to 4.2 °C). This is consistent with results by CMIP5 models, but inconsistent with recent studies that relied on short-term air temperature data affected by natural climate variability.

  4. High-resolution forest carbon stocks and emissions in the Amazon.

    PubMed

    Asner, Gregory P; Powell, George V N; Mascaro, Joseph; Knapp, David E; Clark, John K; Jacobson, James; Kennedy-Bowdoin, Ty; Balaji, Aravindh; Paez-Acosta, Guayana; Victoria, Eloy; Secada, Laura; Valqui, Michael; Hughes, R Flint

    2010-09-21

    Efforts to mitigate climate change through the Reduced Emissions from Deforestation and Degradation (REDD) depend on mapping and monitoring of tropical forest carbon stocks and emissions over large geographic areas. With a new integrated use of satellite imaging, airborne light detection and ranging, and field plots, we mapped aboveground carbon stocks and emissions at 0.1-ha resolution over 4.3 million ha of the Peruvian Amazon, an area twice that of all forests in Costa Rica, to reveal the determinants of forest carbon density and to demonstrate the feasibility of mapping carbon emissions for REDD. We discovered previously unknown variation in carbon storage at multiple scales based on geologic substrate and forest type. From 1999 to 2009, emissions from land use totaled 1.1% of the standing carbon throughout the region. Forest degradation, such as from selective logging, increased regional carbon emissions by 47% over deforestation alone, and secondary regrowth provided an 18% offset against total gross emissions. Very high-resolution monitoring reduces uncertainty in carbon emissions for REDD programs while uncovering fundamental environmental controls on forest carbon storage and their interactions with land-use change. PMID:20823233

  5. Surface seals reduce 1,3-dichloropropene and chloropicrin emissions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Reducing emissions is essential for minimizing the detrimental impact of soil fumigation and for maintaining the availability of fumigants to agricultural uses. This study determined the effectiveness of surface water applications to reduce emissions of 1,3-dichloropropene (1,3-D) and chloropicrin ...

  6. Subsurface manure application to reduce ammonia emissions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Incorporation into soil is generally recommended to reduce ammonia volatilization and nutrient runoff following land application of manures. A range of subsurface applicators are available for manure incorporation with minimal soil disturbance in reduced tillage systems, but none have been widely a...

  7. The 11 Micron Emissions of Carbon Stars

    NASA Astrophysics Data System (ADS)

    Goebel, J. H.; Cheeseman, P.; Gerbault, F.

    1995-08-01

    A new classification scheme of the IRAS LRS carbon stars is presented. It comprises the separation of 718 probable carbon stars into 12 distinct self-similar spectral groupings. Continuum temperatures are assigned and range from 470 to 5000 K. Three distinct dust species are identifiable: SiC, α: C-H, and MgS. In addition to the narrow 11+ microns emission feature that is commonly attributed to SiC, a broad 11+ microns emission feature, that is correlated with the 8.5 and 7.7 microns features, is found and attributed to α:C-H. SiC and α:C-H band strengths are found to correlate with the temperature progression among the Classes. We find a spectral sequence of Classes that reflects the carbon star evolutionary sequence of spectral types, or alternatively developmental sequences of grain condensation in carbon-rich circumstellar shells. If decreasing temperature corresponds to increasing evolution, then decreasing temperature corresponds to increasing C/O resulting in increasing amounts of carbon rich dust, namely α: C-H. If decreasing the temperature corresponds to a grain condensation sequence, then heterogeneous, or induced nucleation scenarios are supported. SiC grains precede α: C-H and form the nuclei for the condensation of the latter material. At still lower temperatures, MgS appears to be quite prevalent. No 11.3 microns PAH features are identified in any of the 718 carbon stars. However, one of the coldest objects, IRAS 15048-5702, and a few others, displays an 11.9 microns emission feature characteristic of laboratory samples of coronene. That feature corresponds to the C-H out of plane deformation mode of aromatic hydrocarbon. This band indicates the presence of unsaturated, sp3, hydrocarbon bonds that may subsequently evolve into saturated bonds, sp2, if, and when, the star enters the planetary nebulae phase of stellar evolution. The effusion of hydrogen from the hydrocarbon grain results in the evolution in wavelength of this 11.9 microns emission

  8. The 11 Micron Emissions of Carbon Stars

    NASA Technical Reports Server (NTRS)

    Goebel, J. H.; Cheeseman, P.; Gerbault, F.

    1995-01-01

    A new classification scheme of the IRAS LRS carbon stars is presented. It comprises the separation of 718 probable carbon stars into 12 distinct self-similar spectral groupings. Continuum temperatures are assigned and range from 470 to 5000 K. Three distinct dust species are identifiable: SiC, alpha:C-H, and MgS. In addition to the narrow 11 + micron emission feature that is commonly attributed to SiC, a broad 11 + micron emission feature, that is correlated with the 8.5 and 7.7 micron features, is found and attributed to alpha:C-H. SiC and alpha:C-H band strengths are found to correlate with the temperature progression among the Classes. We find a spectral sequence of Classes that reflects the carbon star evolutionary sequence of spectral types, or alternatively developmental sequences of grain condensation in carbon-rich circumstellar shells. If decreasing temperature corresponds to increasing evolution, then decreasing temperature corresponds to increasing C/O resulting in increasing amounts of carbon rich dust, namely alpha:C-H. If decreasing the temperature corresponds to a grain condensation sequence, then heterogeneous, or induced nucleation scenarios are supported. SiC grains precede alpha:C-H and form the nuclei for the condensation of the latter material. At still lower temperatures, MgS appears to be quite prevalent. No 11.3 micron PAH features are identified in any of the 718 carbon stars. However, one of the coldest objects, IRAS 15048-5702, and a few others, displays an 11.9 micron emission feature characteristic of laboratory samples of coronene. That feature corresponds to the C-H out of plane deformation mode of aromatic hydrocarbon. This band indicates the presence of unsaturated, sp(sup 3), hydrocarbon bonds that may subsequently evolve into saturated bonds, sp(sup 2), if, and when, the star enters the planetary nebulae phase of stellar evolution. The effusion of hydrogen from the hydrocarbon grain results in the evolution in wavelength of this

  9. Impact of Light-Duty Vehicle Emissions on 21st Century Carbon Dioxide Concentrations

    SciTech Connect

    Smith, Steven J.; Kyle, G. Page

    2007-08-04

    The impact of light-duty passenger vehicle emissions on global carbon dioxide concentrations was estimated using the MAGICC reduced-form climate model combined with the PNNL contribution to the CCSP scenarios product. Our central estimate is that tailpipe light duty vehicle emissions of carbon-dioxide over the 21st century will increase global carbon dioxide concentrations by slightly over 12 ppmv by 2100.

  10. Wildfire effects on carbon stocks and emissions in fuels treated forests (Invited)

    NASA Astrophysics Data System (ADS)

    North, M.; Hurteau, M.

    2010-12-01

    The large carbon stores of many of the worlds’ forests are prone to reversal from wildfire. Fuels treatments can reduce wildfire emissions but at an immediate carbon reduction cost. Comparing these tradeoffs in forest burned by wildfire, we found treatments reduced wildfire emissions by 58% but total carbon loss, including biomass removed, was higher than in untreated forest. However with only 3% of trees alive, untreated forests have more than 70% of their carbon in decomposing stocks likely making them a carbon source for several decades. In wildfire burned forest, fuels treatments have a higher immediate carbon loss ‘cost’, but a significant long-term benefit in avoided emissions from decomposition and reductions in carbon storage.

  11. Reducing uncertainty in methane emission estimates from permafrost peatlands

    NASA Astrophysics Data System (ADS)

    Christensen, Torben R.

    2016-04-01

    Reducing uncertainty in methane emission estimates from permafrost peatlands Torben R. Christensen1,2 and coworkers 1) Department of Physical Geography and Ecosystem Science, Lund University, Sweden 2) Arctic Research Centre, Aarhus University, Denmark Depending on factors including temperature, snow duration and soil moisture conditions, emissions of the greenhouse gas methane from permafrost peatlands can vary by factors of 2-4 between years. This variability is clear in atmospheric measurements of the gas, but a lack of ground-based data is making it hard to locate the methane sources responsible. Methane monitoring in the Arctic is expensive, requiring sophisticated analysis equipment such as power requiring laser spectrometer analysis made in remote places. This also puts demands on the logistics where infrastructures and field stations that offer line-power in the field are in high demand but very rarely found. Research projects therefore typically focus on one site, and run for a year or two. Longer term monitoring programs, which document climate, hydrology, phenology and population dynamics of birds and mammals, rarely include carbon fluxes since it is technically challenging to measure. One that does is the Greenland Ecosystem Monitoring program that started at the Zackenberg research station, which has recorded substantial methane flux variations for almost a decade in North-east Greenland. Such multi-year studies show that, while there is some connection between the amounts of methane released from one year to the next, accurate forecasting is difficult. They also highlight the importance of extending monitoring beyond the growing period into the frozen season, both in spring and autumn. A spatially distributed network of long-term monitoring stations in the Arctic, with consistency between measurements, is badly needed to improve this situation. Productive methane 'hot spots', many sporadic, have also been identified in recent studies. By ventilating

  12. Heat Pipes Reduce Engine-Exhaust Emissions

    NASA Technical Reports Server (NTRS)

    Schultz, D. F.

    1986-01-01

    Increased fuel vaporization raises engine efficiency. Heat-pipe technology increased efficiency of heat transfer beyond that obtained by metallic conduction. Resulted in both improved engine operation and reduction in fuel consumption. Raw material conservation through reduced dependence on strategic materials also benefit from this type of heat-pipe technology. Applications result in improved engine performance and cleaner environment.

  13. Pilot study to reduce emissions, improve health, and offset BC emissions through the distribution of improved cook stoves in Nepal

    NASA Astrophysics Data System (ADS)

    Banmali Pradhan, B.; Panday, A. K.; Surapipith, V.

    2013-12-01

    In most developing countries, wood and other biomass fuels are still the primary source of energy for the majority of the people, particularly the poor. It is estimated that cook stoves account for approximately 20% of global black carbon emissions. In Nepal 87% of energy is supplied from traditional biomass and 75% of households still depend on biomass as a cooking fuel. The substitution of traditional cook stoves with improved cook stoves provides an important way to reduce black carbon emissions. In 2013 the International Centre for Integrated Mountain Development (ICIMOD) has commenced a pilot study that both examines ways to effectively disseminate improved cookstoves across remote rural mountain regions, and also quantifies the resulting changes in emissions, air quality and health. The selected study area is in Bajrabarahi Village in Makawanpur district, to the southwest of Kathmandu. The study area consists of around 1600 households, which are divided into control groups and groups where the cook stove intervention is taking place. The study complements the ';Clean Cooking energy solution for all by 2017' announced by the Government of Nepal recently, and will provide insights to the government on ways to effectively reduce black carbon emissions from cook stoves. To make the study robust and sustainable, local women's group and a local medical institution are involved in the project right from the conceptualization stage. The study region has been chosen in part because the medical school Patan Academy of Health Sciences (PAHS) has already started a long term health assessment in the region, and has built up considerable local contacts. The local women's group is working on the modality of cook stove distribution through micro credit programmes in the village. We will distribute the best available manufactured, fan-assisted cook stoves that are expected to reduce BC emissions the most. Health assessments, emissions estimates, as well as measurements of

  14. Carbon emission targets for driving sustainable mobility with US light-duty vehicles.

    PubMed

    Grimes-Casey, Hilary G; Keoleian, Gregory A; Willcox, Blair

    2009-02-01

    Models and frameworks to guide "sustainable mobility" of personal transportation lack definitive quantitative targets. This paper defines sustainable mobility targets for US light-duty vehicles (LDVs) to help stabilize atmospheric carbon dioxide concentrations at 450 or 550 ppm. The Intergovernmental Panel on Climate Change carbon stabilization pathways are used to equitably distribute future carbon dioxide emissions to the US. Allowable US emissions are then allocated to the LDV sector according to the current share of national emissions. Average on-road LDV well-to-wheel carbon emissions must be reduced from 160 g/mile (2002) to 20 g/mile by 2050 to contribute to a 450 ppm CO2 goal. Strategies to reduce LDV greenhouse gas emissions include reducing travel demand, improving average fuel economy, and utilizing low-carbon ethanol. Simulations using EIA modeling parameters indicate that average LDV fuel economy must reach 136 mpg, cellulosic ethanol must make up over 83% of fuel market share, or annual LDV travel demand must be reduced by about 53% by 2050 to help meet LDV greenhouse gas targets based on a 450 ppm CO2 stabilization goal. Recent federal energy security policy and plug-in hybrid technology programs may also help meet LDV carbon emission targets in the short term by reducing gasoline use, but an aggressive combination of strategies will be needed to keep vehicle CO2 in line with an emissions target to 2050. PMID:19244987

  15. Incentives for reducing emissions in Krakow

    SciTech Connect

    Uberman, R.; Pierce, B.; Lazecki, A.

    1994-06-01

    This effort is identifying, specific incentives that may be used by Krakow city officials to encourage, residents to change the way they heat their homes and businesses in order to reduce pollution. This paper describes the incentives study for converting small coal or coke-fired boilers to gas in the Old Town area. A similar study looked at incentives for expanding the district heating system and future analyses will be performed for home stove options.

  16. Apparatus for reducing solvent luminescence background emissions

    DOEpatents

    Affleck, R.L.; Ambrose, W.P.; Demas, J.N.; Goodwin, P.M.; Johnson, M.E.; Keller, R.A.; Petty, J.T.; Schecker, J.A.; Wu, M.

    1998-11-10

    The detectability of luminescent molecules in solution is enhanced by reducing the background luminescence due to impurity species also present in the solution. A light source that illuminates the solution acts to photolyze the impurities so that the impurities do not luminesce in the fluorescence band of the molecule of interest. Molecules of interest may be carried through the photolysis region in the solution or may be introduced into the solution after the photolysis region. 6 figs.

  17. Apparatus for reducing solvent luminescence background emissions

    DOEpatents

    Affleck, Rhett L.; Ambrose, W. Patrick; Demas, James N.; Goodwin, Peter M.; Johnson, Mitchell E.; Keller, Richard A.; Petty, Jeffrey T.; Schecker, Jay A.; Wu, Ming

    1998-01-01

    The detectability of luminescent molecules in solution is enhanced by reducing the background luminescence due to impurity species also present in the solution. A light source that illuminates the solution acts to photolyze the impurities so that the impurities do not luminesce in the fluorescence band of the molecule of interest. Molecules of interest may be carried through the photolysis region in the solution or may be introduced into the solution after the photolysis region.

  18. [Environmental efficiency evaluation under carbon emission constraint in Western China].

    PubMed

    Rong, Jian-bo; Yan, Li-jiao; Huang, Shao-rong; Zhang, Ge

    2015-06-01

    This research used the SBM model based on undesirable outputs to measure the static environmental efficiency of Western China under carbon emission constraint from 2000 to 2012. The researchers also utilized the Malmquist index to further analyze the change tendency of environmental efficiency. Additionally, Tobit regression analysis was used to study the factors relevant to environmental efficiency. Practical solutions to improve environmental quality in Western China were put forward. The study showed that in Western China, environmental efficiency with carbon emission constraint was significantly lower than that without carbon emission constraint, and the difference could be described as an inverse U-shaped curve which increased at first and then decreased. Guang-xi and Inner Mongolia, the two provinces met the effective environmental efficiency levels all the time under carbon emission constraint. However, the five provinces of Guizhou, Gansu, Qinghai, Ningxia and Xinjiang did not. Furthermore, Ningxia had the lowest level of environmental efficiency, with a score between 0.281-0.386. Although the environmental efficiency of most provinces was currently at an ineffective level, the environmental efficiency quality was gradually improving at an average speed of 6.6%. Excessive CO2 emission and a large amount of energy consumption were the primary factors causing environmental inefficiency in Western China, and energy intensity had the most negative impact on the environmental efficiency. The increase of import and export trade reduced the environmental efficiency significantly in Western China, while the increase of foreign direct investment had a positive effect on its environmental efficiency. PMID:26572038

  19. Elements for the expected mechanisms on 'reduced emissions from deforestation and degradation, REDD' under UNFCCC

    NASA Astrophysics Data System (ADS)

    Mollicone, D.; Freibauer, A.; Schulze, E. D.; Braatz, S.; Grassi, G.; Federici, S.

    2007-10-01

    Carbon emissions from deforestation and degradation account for about 20% of global anthropogenic emissions. Strategies and incentives for reduced emissions from deforestation and degradation (REDD) have emerged as one of the most active areas in the international climate change negotiations under the United Nations Framework Convention on Climate Change (UNFCCC). While the current negotiations focus on a REDD mechanism in developing countries, it should be recognized that risks of carbon losses from forests occur in all climate zones and also in industrialized countries. A future climate change agreement would be more effective if it included all carbon losses and gains from land use in all countries and climate zones. The REDD mechanism will be an important step towards reducing emissions from land use change in developing countries, but needs to be followed by steps in other land use systems and regions. A national approach to REDD and significant coverage globally are needed to deal with the risk that deforestation and degradation activities are displaced rather than avoided. Favourable institutional and governance conditions need to be established that guarantee in the long-term a stable incentive and control system for maintaining forest carbon stocks. Ambitious emission reductions from deforestation and forest degradation need sustained financial incentives, which go beyond positive incentives for reduced emissions but also give incentives for sustainable forest management. Current data limitations need—and can be—overcome in the coming years to allow accurate accounting of reduced emissions from deforestation and degradation. A proper application of the conservativeness approach in the REDD context could allow a simplified reporting of emissions from deforestation in a first phase, consistent with the already agreed UNFCCC reporting principles.

  20. Deterministic Cold Cathode Electron Emission from Carbon Nanofibre Arrays

    NASA Astrophysics Data System (ADS)

    Cole, Matthew T.; Teo, Kenneth B. K.; Groening, Oliver; Gangloff, Laurent; Legagneux, Pierre; Milne, William I.

    2014-05-01

    The ability to accurately design carbon nanofibre (CN) field emitters with predictable electron emission characteristics will enable their use as electron sources in various applications such as microwave amplifiers, electron microscopy, parallel beam electron lithography and advanced Xray sources. Here, highly uniform CN arrays of controlled diameter, pitch and length were fabricated using plasma enhanced chemical vapour deposition and their individual emission characteristics and field enhancement factors were probed using scanning anode field emission mapping. For a pitch of 10 µm and a CN length of 5 µm, the directly measured enhancement factors of individual CNs was 242, which was in excellent agreement with conventional geometry estimates (240). We show here direct empirical evidence that in regular arrays of vertically aligned CNs the overall enhancement factor is reduced when the pitch between emitters is less than half the emitter height, in accordance to our electrostatic simulations. Individual emitters showed narrow Gaussian-like field enhancement distributions, in excellent agreement with electric field simulations.

  1. Analysis of Strategies for Reducing Multiple Emissions from Electric Power Plants: SO2, Nox, CO2

    EIA Publications

    2001-01-01

    This report responds to a request received from Senator David McIntosh on June 29, 2000 to analyze the impacts on energy consumers and producers of coordinated strategies to reduce emissions of sulfur dioxide, nitrogen oxides, and carbon dioxide at U.S. power plants.

  2. REDUCING EMISSIONS FROM THE WOOD FURNITURE INDUSTRY WITH WATERBORNE COATINGS

    EPA Science Inventory

    This program was initiated to develop meaningful, defensible, and reliable data on emission reduction benefits from the use of reduced hydrocarbon finishes. The program also included assessing add-on emission control options and considering installation aspects such as costs. Thi...

  3. Reducing global NOx emissions: developing advanced energy and transportation technologies.

    PubMed

    Bradley, Michael J; Jones, Brian M

    2002-03-01

    Globally, energy demand is projected to continue to increase well into the future. As a result, global NOx emissions are projected to continue on an upward trend for the foreseeable future as developing countries increase their standards of living. While the US has experienced improvements in reducing NOx emissions from stationary and mobile sources to reduce ozone, further progress is needed to reduce the health and ecosystem impacts associated with NOx emissions. In other parts of the world, (in developing countries in particular) NOx emissions have been increasing steadily with the growth in demand for electricity and transportation. Advancements in energy and transportation technologies may help avoid this increase in emissions if appropriate policies are implemented. This paper evaluates commercially available power generation and transportation technologies that produce fewer NOx emissions than conventional technologies, and advanced technologies that are on the 10-year commercialization horizon. Various policy approaches will be evaluated which can be implemented on the regional, national and international levels to promote these advanced technologies and ultimately reduce NOx emissions. The concept of the technology leap is offered as a possibility for the developing world to avoid the projected increases in NOx emissions. PMID:12078003

  4. Reducing Uncertainty in Methane Emission Estimates from Permafrost Environments

    NASA Astrophysics Data System (ADS)

    Christensen, T. R.; Mastepanov, M.; Lund, M.; Tamstorf, M. P.; Parmentier, F. J. W.; Rysgård, S.; Lilienthal, A. J.

    2014-12-01

    Depending on factors including temperature, snow duration and soil moisture conditions, emissions of the greenhouse gas methane from permafrost wetlands can vary by factors of 2-4 between years. This variability is clear in atmospheric measurements of the gas, but a lack of ground-based data is making it hard to locate the methane sources responsible. Methane monitoring in the Arctic is expensive, requiring sophisticated analysis equipment such as power requiring laser spectrometer analysis made in remote places. This also puts demands on the logistics where infrastructures and field stations that offer line-power in the field are in high demand but very rarely found. Research projects therefore typically focus on one site, and run for a year or two. Longer term monitoring programs, which document climate, hydrology, phenology and population dynamics of birds and mammals, rarely include carbon fluxes since it is technically challenging to measure. One that does is the Greenland Ecosystem Monitoring program that started at the Zackenberg research station, which has recorded substantial methane flux variations for almost a decade in North-east Greenland. Such multi-year studies show that, while there is some connection between the amounts of methane released from one year to the next, accurate forecasting is difficult. They also highlight the importance of extending monitoring beyond the growing period into the frozen season, both in spring and autumn. A spatially distributed network of long-term monitoring stations in the Arctic, with consistency between measurements, is badly needed to improve this situation. Productive methane 'hot spots', many sporadic, have also been identified in recent studies. By ventilating surface waters, storms trigger emissions in the East Siberian Sea Shelf. Shallow lakes formed when permafrost thaws can belch methane from decomposing old organic deposits, of which there are huge amounts in the Arctic. All of these potentially important

  5. OPTIONS FOR REDUCING REFRIGERANT EMISSIONS FROM SUPERMARKET SYSTEMS

    EPA Science Inventory

    The report was prepared to assist personnel responsible for the design, construction, and maintenance of retail food refrigeration equipment in making knowledgeable decisions regarding the implementation of refrigerant-emissions-reducing practices and technologies. It characteriz...

  6. Prospects for residential oil burners with reduced emissions

    SciTech Connect

    Butcher, T.A.; Krajewski, R.F.; Celebi, Y.; McDonald, R.J.; Batey, J.

    1992-04-01

    In considering the emissions characteristics of residential oil heating equipment it is important to consider the magnitude of these emissions relative to all other sources. Laboratory and field test data show that home oil burners produce very low levels of pollutants when compared to all other combustion sources in the US. Home oil burners are relatively clean burning and produce less air pollution than the average combustion source in the US. This is especially true for carbon monoxide, particulates, and hydrocarbons, which are a small fraction of the average emission of other combustion equipment. In this paper results are presented of emission tests done with a number of oil burners selected as being representative of modern equipment or representing a recent development trend or a novel approach. The primary purpose of this work was to provide a benchmark of what oil equipment can do today and what the effects of some of these alternative designs are on emissions.

  7. Heat pipes to reduce engine exhaust emissions

    NASA Technical Reports Server (NTRS)

    Schultz, D. F. (Inventor)

    1984-01-01

    A fuel combustor is presented that consists of an elongated casing with an air inlet conduit portion at one end, and having an opposite exit end. An elongated heat pipe is mounted longitudinally in the casing and is offset from and extends alongside the combustion space. The heat pipe is in heat transmitting relationship with the air intake conduit for heating incoming air. A guide conduit structure is provided for conveying the heated air from the intake conduit into the combustion space. A fuel discharge nozzle is provided to inject fuel into the combustion space. A fuel conduit from a fuel supply source has a portion engaged in heat transfer relationship of the heat pipe for preheating the fuel. The downstream end of the heat pipe is in heat transfer relationship with the casing and is located adjacent to the downstream end of the combustion space. The offset position of the heat pipe relative to the combustion space minimizes the quenching effect of the heat pipe on the gaseous products of combustion, as well as reducing coking of the fuel on the heat pipe, thereby improving the efficiency of the combustor.

  8. Method and apparatus for reducing NOx emissions

    SciTech Connect

    Spokoyny, F.E.; Krigmont, H.V.

    1993-08-24

    A method is described of reducing NOx from a flue gas stream produced from a burner, which flue gas stream passes from the burner through a rotary regenerative heat exchanger which rotates in a direction generally transverse to the direction of the flow of the flue gas stream and wherein at least a portion of the heat transfer elements of the heat exchanger carry a catalyst which, in the presence of a nitrogeneous compound, promote the reduction of NOx from the flue gas stream passing thereby, comprising the steps of: injecting a quantity of a nitrogeneous compound onto the catalyzed heat transfer elements, such injecting being at a plurality of fixed locations along the arcuate path of travel of the catalyzed elements with respect to the flue gas stream; determining the temperature of the portion of the heat transfer elements as such elements travel in an arcuate path with respect to the flow of the flue gas stream; and in response to said step of determining, selectively varying the quantity of nitrogeneous compound injected at each of such fixed locations.

  9. Stability of Reduced Carbon in the Mantle

    NASA Astrophysics Data System (ADS)

    Hastings, Patrick Timothy, Jr.

    Reduced carbon in the mantle is commonly thought to be chiefly in diamond, but experiments suggest that at >250 km the mantle contains small amounts (0.1-1 %) of FeNi alloy [1, 2, 3]. Thus, alloy may be a significant host of reduced C [4], but little is known about C solubility of FeNi alloy under mantle conditions. To determine the carbon solubility in FeNi alloy and melt, we conducted experiments in the system Fe-Ni-C with bulk compositions having 5 wt. % C and variable Fe/(Fe+Ni) at 3 to 7 GPa and 1000--1400°C. Experiments at 3 GPa and 1000--1250 °C were performed in an end loaded piston cylinder apparatus; those at 5 and 7 GPa and 1200--1400°C were performed in a 1000 ton Walker-style octahedral multianvil. At 3 GPa, Fe-rich melts contain up to 4.5 wt. % C, but Ni-rich (>25 mole% Ni) compositions remain subsolidus at 1250°C. The solubility of carbon in pure Fe and Ni metal are 2 wt. % and 1 wt. % respectively, but in the alloy passes through a minimum of 0.4 wt. % for Fe0.2Ni0.8. Assuming that these concentrations apply at higher temperatures and pressures (as will be tested by future experiments) allows a first estimate of the potential storage of C in FeNi alloy in the mantle. If the mantle at 250 km contains 0.1-0.2 wt.% Ni-rich (Fe0.4Ni0.6) alloy, increasing with depth to 1 wt.% Fe-rich (Fe0.88Ni0.12) alloy at 700 km [1,2], then maximum storage of C in alloy rises from 5 ppm in the deep upper mantle to 180 ppm in the shallow lower mantle. For mantle similar to the MORB source, with ~10-30 ppm C [5], alloy cannot store all C in the deep upper mantle but can in the lower mantle. For OIB sources with 33-500 ppm C [5], complete storage in alloy is less likely. Additional phases will be diamond in the upper mantle, as our experiments and previous work [6] indicate that carbide is not stable in equilibrium with Ni-rich alloy, and carbide melt in the lower mantle. [1] Frost et al (2004) Nature 428 409-412. [2] Frost and McCammon (2008) EPSL 36 389-420. [3

  10. Texturing Copper To Reduce Secondary Emission Of Electrons

    NASA Technical Reports Server (NTRS)

    Jensen, Kenneth A.; Curren, Arthur N.; Roman, Robert F.

    1995-01-01

    Ion-beam process produces clean, deeply textured surfaces on copper substrates with reduced secondary electron emission. In process, molybdenum ring target positioned above and around copper substrate. Target potential repeatedly switched on and off. Switching module described in "High-Voltage MOSFET Switching Circuit" (LEW-15986). Useful for making collector electrodes for traveling-wave-tube and klystron microwave amplifiers, in which secondary emission of electrons undesirable because of reducing efficiency.

  11. Status of Technological Advancements for Reducing Aircraft Gas Turbine Engine Pollutant Emissions

    NASA Technical Reports Server (NTRS)

    Rudey, R. A.

    1975-01-01

    Combustor test rig results indicate that substantial reductions from current emission levels of carbon monoxide (CO), total unburned hydrocarbons (THC), oxides of nitrogen (NOx), and smoke are achievable by employing varying degrees of technological advancements in combustion systems. Minor to moderate modifications to existing conventional combustors produced significant reductions in CO and THC emissions at engine low power (idle/taxi) operating conditions but did not effectively reduce NOx at engine full power (takeoff) operating conditions. Staged combusiton techniques were needed to simultaneously reduce the levels of all the emissions over the entire engine operating range (from idle to takeoff). Emission levels that approached or were below the requirements of the 1979 EPA standards were achieved with the staged combustion systems and in some cases with the minor to moderate modifications to existing conventional combustion systems. Results from research programs indicate that an entire new generation of combustor technology with extremely low emission levels may be possible in the future.

  12. Black carbon emissions in China from 1949 to 2050.

    PubMed

    Wang, Rong; Tao, Shu; Wang, Wentao; Liu, Junfeng; Shen, Huizhong; Shen, Guofeng; Wang, Bin; Liu, Xiaopeng; Li, Wei; Huang, Ye; Zhang, Yanyan; Lu, Yan; Chen, Han; Chen, Yuanchen; Wang, Chen; Zhu, Dan; Wang, Xilong; Li, Bengang; Liu, Wenxin; Ma, Jianmin

    2012-07-17

    Black carbon (BC) emissions from China are of global concern. A new BC emission inventory (PKU-BC(China)) has been developed with the following improvements: (1) The emission factor database was updated; (2) a 0.1° × 0.1° gridded map was produced for 2007 based on county-level proxies; (3) time trends were derived for 1949-2007 and predicted for 2008-2050; and (4) the uncertainties associated with the inventory were quantified. It was estimated that 1957 Gg of BC were emitted in China in 2007, which is greater than previously reported. Residential coal combustion was the largest source, followed by residential biofuel burning, coke production, diesel vehicles, and brick kilns. By using a county-level disaggregation method, spatial bias in province-level disaggregation, mainly due to uneven per capita emissions within provinces, was reduced by 42.5%. Emissions increased steadily since 1949 until leveling off in the mid-1990s, due to a series of technological advances and to socioeconomic progress. BC emissions in China in 2050 are predicted to be 920-2183 Gg/yr under various scenarios; and the industrial and transportation sectors stand to benefit the most from technological improvements. PMID:22730898

  13. Provincial variation of carbon emissions from bituminous coal: Influence of inertinite and other factors

    USGS Publications Warehouse

    Quick, J.C.; Brill, T.

    2002-01-01

    We observe a 1.3 kg C/net GJ variation of carbon emissions due to inertinite abundance in some commercially available bituminous coal. An additional 0.9 kg C/net GJ variation of carbon emissions is expected due to the extent of coalification through the bituminous rank stages. Each percentage of sulfur in bituminous coal reduces carbon emissions by about 0.08 kg C/net GJ. Other factors, such as mineral content, liptinite abundance and individual macerals, also influence carbon emissions, but their quantitative effect is less certain. The large range of carbon emissions within the bituminous rank class suggests that rank- specific carbon emission factors are provincial rather than global. Although carbon emission factors that better account for this provincial variation might be calculated, we show that the data used for this calculation may vary according to the methods used to sample and analyze coal. Provincial variation of carbon emissions and the use of different coal sampling and analytical methods complicate the verification of national greenhouse gas inventories. Published by Elsevier Science B.V.

  14. The Effect of Emissions Trading And Carbon Sequestration on The Cost Of CO2 Emissions Mitigation

    SciTech Connect

    Mahasenan, Natesan; Scott, Michael J.; Smith, Steven J.

    2002-08-05

    The deployment of carbon capture and sequestration (CC&S) technologies is greatly affected by the marginal cost of controlling carbon emissions (also the value of carbon, when emissions permits are traded). Emissions limits that are more stringent in the near term imply higher near-term carbon values and therefore encourage the local development and deployment of CC&S technologies. In addition, trade in emissions obligations lowers the cost of meeting any regional or global emissions limit and so affects the rate of penetration of CC&S technologies. We examine the effects of the availability of sequestration opportunities and emissions trading (either within select regions or globally) on the cost of emissions mitigation and compliance with different emissions reduction targets for the IPCC SRES scenarios. For each base scenario and emissions target, we examine the issues outlined above and present quantitative estimates for the impacts of trade and the availability of sequestration opportunities in meeting emissions limitation obligations.

  15. Carbon dioxide emission from bamboo culms.

    PubMed

    Zachariah, E J; Sabulal, B; Nair, D N K; Johnson, A J; Kumar, C S P

    2016-05-01

    Bamboos are one of the fastest growing plants on Earth, and are widely considered to have high ability to capture and sequester atmospheric carbon, and consequently to mitigate climate change. We tested this hypothesis by measuring carbon dioxide (CO2 ) emissions from bamboo culms and comparing them with their biomass sequestration potential. We analysed diurnal effluxes from Bambusa vulgaris culm surface and gas mixtures inside hollow sections of various bamboos using gas chromatography. Corresponding variations in gas pressure inside the bamboo section and culm surface temperature were measured. SEM micrographs of rhizome and bud portions of bamboo culms were also recorded. We found very high CO2 effluxes from culm surface, nodes and buds of bamboos. Positive gas pressure and very high concentrations of CO2 were observed inside hollow sections of bamboos. The CO2 effluxes observed from bamboos were very high compared to their carbon sequestration potential. Our measurements suggest that bamboos are net emitters of CO2 during their lifespan. PMID:26802362

  16. Laser-induced light emission from carbon nanoparticles

    SciTech Connect

    Osswald, S.; Behler, K.; Gogotsi, Y.

    2008-10-01

    Strong absorption of light in a broad wavelength range and poor thermal conductance between particles of carbon nanomaterials, such as nanotubes, onions, nanodiamond, and carbon black, lead to strong thermal emission (blackbody radiation) upon laser excitation, even at a very low (milliwatts) power. The lasers commonly used during Raman spectroscopy characterization of carbon can cause sample heating to very high temperatures. While conventional thermometry is difficult in the case of nanomaterials, Raman spectral features, such as the G band of graphitic carbon and thermal emission spectra were used to estimate the temperature during light emission that led to extensive graphitization and evaporation of carbon nanomaterials, indicating local temperatures exceeding 3500 deg. C.

  17. Estimates of increased black carbon emissions from electrostatic precipitators during powdered activated carbon injection for mercury emissions control.

    PubMed

    Clack, Herek L

    2012-07-01

    The behavior of mercury sorbents within electrostatic precipitators (ESPs) is not well-understood, despite a decade or more of full-scale testing. Recent laboratory results suggest that powdered activated carbon exhibits somewhat different collection behavior than fly ash in an ESP and particulate filters located at the outlet of ESPs have shown evidence of powdered activated carbon penetration during full-scale tests of sorbent injection for mercury emissions control. The present analysis considers a range of assumed differential ESP collection efficiencies for powdered activated carbon as compared to fly ash. Estimated emission rates of submicrometer powdered activated carbon are compared to estimated emission rates of particulate carbon on submicrometer fly ash, each corresponding to its respective collection efficiency. To the extent that any emitted powdered activated carbon exhibits size and optical characteristics similar to black carbon, such emissions could effectively constitute an increase in black carbon emissions from coal-based stationary power generation. The results reveal that even for the low injection rates associated with chemically impregnated carbons, submicrometer particulate carbon emissions can easily double if the submicrometer fraction of the native fly ash has a low carbon content. Increasing sorbent injection rates, larger collection efficiency differentials as compared to fly ash, and decreasing sorbent particle size all lead to increases in the estimated submicrometer particulate carbon emissions. PMID:22663136

  18. A Theory for How Global Warming Mechanistically Depends on Cumulative Carbon Emissions Over Time

    NASA Astrophysics Data System (ADS)

    Goodwin, P.; Williams, R. G.; Ridgwell, A. J.

    2014-12-01

    Climate model experiments reveal that transient global warming is nearly proportional to cumulative carbon emissions on multi-decadal to millennial timescales. However, it is not quantitatively understood how this near linear dependence between warming and cumulative carbon emissions arises in transient climate simulations, nor why the proportionality of warming is largely independent of emission scenario. Here, we present the first theoretical equation for how global warming depends on cumulative carbon emissions over time for an atmosphere-ocean system. For the present, our theory identifies a sensitivity of surface warming to emission of 1.5±0.7 K for every 1000 Pg of carbon emitted, reducing by only 10 to 20% by the end of the century and beyond. The sensitivity remaining nearly constant over time is due to partially-opposing thermal and carbon responses in a coupled atmosphere-ocean, as well as reflecting how warming is proportional to cumulative carbon emissions after many centuries. Incorporating estimates of terrestrial carbon uptake into our analysis reduces the sensitivity of surface warming to 1.1±0.5 K for every 1000 Pg of carbon emitted, but does not significantly alter the percentage reduction in warming sensitivity over the 21st century. Our theory provides an analytical framework to interpret model projections of global warming.

  19. [Monitoring gas concentration from carbon emissions by remote sensing].

    PubMed

    Wang, Li-Wen; Wei, Ya-Xing

    2012-06-01

    Global climate warming has become the focus question of international global climate change research, and is an important factor influencing world economy, political situation, and ecological environment. Produced carbon emission gases such as CO2, CH4, N2O, etc. caused by human activity are the main reason for global warming. In order to forecast future climate change and construct accurate carbon cycle model, monitoring accuracy of gas concentration from carbon emission must be improved. In the present paper, the newest progress in the international research results about monitoring gas concentration from carbon emissions by remote sensing was considered, monitoring method for carbon emissions was introduced, and remotely sensed monitoring technology about gas concentration from carbon emissions (including thermal infrared, sun spectrum, active remote sensing monitoring technology) was stated. In detail, several present and future satellite sensors were introduced (including TOVS, AIRS, IASI, SCIAMACHY, GOSAT, OCO, A-SCOPE and ASCENDS), and monitoring results achieved by these sensors were analyzed. PMID:22870656

  20. A synthesis of carbon dioxide emissions from fossil-fuel combustion

    SciTech Connect

    Andres, Robert Joseph; Boden, Thomas A; Breon, F.-M.; Erickson, D; Gregg, J. S.; Jacobson, Andrew; Marland, Gregg; Miller, J.; Oda, T; Raupach, Michael; Rayner, P; Treanton, K.

    2012-01-01

    This synthesis discusses the emissions of carbon dioxide from fossil-fuel combustion and cement production. While much is known about these emissions, there is still much that is unknown about the details surrounding these emissions. This synthesis explores 5 our knowledge of these emissions in terms of why there is concern about them; how they are calculated; the major global efforts on inventorying them; their global, regional, and national totals at different spatial and temporal scales; how they are distributed on global grids (i.e. maps); how they are transported in models; and the uncertainties associated with these different aspects of the emissions. The magnitude of emissions 10 from the combustion of fossil fuels has been almost continuously increasing with time since fossil fuels were first used by humans. Despite events in some nations specifically designed to reduce emissions, or which have had emissions reduction as a byproduct of other events, global total emissions continue their general increase with time. Global total fossil-fuel carbon dioxide emissions are known to within 10% uncertainty (95% 15 confidence interval). Uncertainty on individual national total fossil-fuel carbon dioxide emissions range from a few percent to more than 50 %. The information discussed in this manuscript synthesizes global, regional and national fossil-fuel carbon dioxide emissions, their distributions, their transport, and the associated uncertainties.

  1. Urban energy consumption and related carbon emission estimation: a study at the sector scale

    NASA Astrophysics Data System (ADS)

    Lu, Weiwei; Chen, Chen; Su, Meirong; Chen, Bin; Cai, Yanpeng; Xing, Tao

    2013-12-01

    With rapid economic development and energy consumption growth, China has become the largest energy consumer in the world. Impelled by extensive international concern, there is an urgent need to analyze the characteristics of energy consumption and related carbon emission, with the objective of saving energy, reducing carbon emission, and lessening environmental impact. Focusing on urban ecosystems, the biggest energy consumer, a method for estimating energy consumption and related carbon emission was established at the urban sector scale in this paper. Based on data for 1996-2010, the proposed method was applied to Beijing in a case study to analyze the consumption of different energy resources (i.e., coal, oil, gas, and electricity) and related carbon emission in different sectors (i.e., agriculture, industry, construction, transportation, household, and service sectors). The results showed that coal and oil contributed most to energy consumption and carbon emission among different energy resources during the study period, while the industrial sector consumed the most energy and emitted the most carbon among different sectors. Suggestions were put forward for energy conservation and emission reduction in Beijing. The analysis of energy consumption and related carbon emission at the sector scale is helpful for practical energy saving and emission reduction in urban ecosystems.

  2. Carbon storage and nitrous oxide emissions of cropping systems in eastern Washington: A simulation study

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Conservation tillage is an agricultural strategy to mitigate atmospheric greenhouse gas (GHG) emissions. In eastern Washington we evaluated the long-term effects of conventional tillage (CT), reduced tillage (RT) and no-tillage (NT) on soil organic carbon (SOC) storage and nitrous oxide emissions at...

  3. Reducing CO2 emissions and energy consumption of heat-integrated distillation systems.

    PubMed

    Gadalla, Mamdouh A; Olujic, Zarko; Jansens, Peter J; Jobson, Megan; Smith, Robin

    2005-09-01

    Distillation systems are energy and power intensive processes and contribute significantly to the greenhouse gases emissions (e.g. carbon dioxide). Reducing CO2 emissions is an absolute necessity and expensive challenge to the chemical process industries in orderto meetthe environmental targets as agreed in the Kyoto Protocol. A simple model for the calculation of CO2 emissions from heat-integrated distillation systems is introduced, considering typical process industry utility devices such as boilers, furnaces, and turbines. Furnaces and turbines consume large quantities of fuels to provide electricity and process heats. As a result, they produce considerable amounts of CO2 gas to the atmosphere. Boilers are necessary to supply steam for heating purposes; besides, they are also significant emissions contributors. The model is used in an optimization-based approach to optimize the process conditions of an existing crude oil atmospheric tower in order to reduce its CO2 emissions and energy demands. It is also applied to generate design options to reduce the emissions from a novel internally heat-integrated distillation column (HIDiC). A gas turbine can be integrated with these distillation systems for larger emissions reduction and further energy savings. Results show that existing crude oil installations can save up to 21% in energy and 22% in emissions, when the process conditions are optimized. Additionally, by integrating a gas turbine, the total emissions can be reduced further by 48%. Internal heat-integrated columns can be a good alternative to conventional heat pump and other energy intensive close boiling mixtures separations. Energy savings can reach up to 100% with respect to reboiler heat requirements. Emissions of these configurations are cut down by up to 83%, compared to conventional units, and by 36%, with respect to heat pump alternatives. Importantly, cost savings and more profit are gained in parallel to emissions minimization. PMID:16190250

  4. Variability of building environmental assessment tools on evaluating carbon emissions

    SciTech Connect

    Ng, S. Thomas Chen Yuan Wong, James M.W.

    2013-01-15

    With an increasing importance of sustainability in construction, more and more clients and designers employ building environmental assessment (BEA) tools to evaluate the environmental friendliness of their building facilities, and one important aspect of evaluation in the BEA models is the assessment of carbon emissions. However, in the absence of any agreed framework for carbon auditing and benchmarking, the results generated by the BEA tools might vary significantly which could lead to confusion or misinterpretation on the carbon performance of a building. This study thus aims to unveil the properties of and the standard imposed by the current BEA models on evaluating the life cycle carbon emissions. The analyses cover the (i) weighting of energy efficiency and emission levels among various environmental performance indicators; (ii) building life cycle stages in which carbon is taken into consideration; (iii) objectiveness of assessment; (iv) baseline set for carbon assessment; (v) mechanism for benchmarking the emission level; and (v) limitations of the carbon assessment approaches. Results indicate that the current BEA schemes focus primarily on operational carbon instead of the emissions generated throughout the entire building life cycle. Besides, the baseline and benchmark for carbon evaluation vary significantly among the BEA tools based on the analytical results of a hypothetical building. The findings point to the needs for a more transparent framework for carbon auditing and benchmarking in BEA modeling. - Highlights: Black-Right-Pointing-Pointer Carbon emission evaluation in building environmental assessment schemes are studied. Black-Right-Pointing-Pointer Simulative carbon emission is modeled for building environmental assessment schemes. Black-Right-Pointing-Pointer Carbon assessments focus primarily on operational stage instead of entire lifecycle. Black-Right-Pointing-Pointer Baseline and benchmark of carbon assessment vary greatly among BEA

  5. The challenges of reducing greenhouse gas emissions and air pollution through energy sources: evidence from a panel of developed countries.

    PubMed

    Akhmat, Ghulam; Zaman, Khalid; Shukui, Tan; Sajjad, Faiza; Khan, Muhammad Azhar; Khan, Muhammad Zahir

    2014-06-01

    The objective of the study is to investigate the long-run relationship between climatic factors (i.e., greenhouse gas emissions, agricultural methane emissions, and industrial nitrous oxide emission), air pollution (i.e., carbon dioxide emissions), and energy sources (i.e., nuclear energy; oil, gas, and coal energy; and fossil fuel energy) in the panel of 35 developed countries (including EU-15, new EU member states, G-7, and other countries) over a period of 1975-2012. In order to achieve this objective, the present study uses sophisticated panel econometric techniques including panel cointegration, panel fully modified OLS (FMOLS), and dynamic OLS (DOLS). The results show that there is a long-run relationship between the variables. Nuclear energy reduces greenhouse gases and carbon emissions; however, the other emissions, i.e., agricultural methane emissions and industrial nitrous oxide, are still to increase during the study period. Electricity production from oil, gas, and coal sources increases the greenhouse gases and carbon emissions; however, the intensity to increase emissions is far less than the intensity to increase emissions through fossil fuel. Policies that reduce emissions of greenhouse gases can simultaneously alter emissions of conventional pollutants that have deleterious effects on human health and the environment. PMID:24584642

  6. EVALUATION OF VOC (VOLATILE CARBON) EMISSIONS FROM WASTEWATER SYSTEMS (SECONDARY EMISSIONS)

    EPA Science Inventory

    The technical objective of this project was to obtain data for evaluating volatile carbon (VOC) emissions from wastewater treatment facilities for the synthetic organic chemicals manufacturing industry (SOCMI). VOC emissions data were obtained using the Concentration-Profile tech...

  7. Using Carbon Emissions Data to "Heat Up" Descriptive Statistics

    ERIC Educational Resources Information Center

    Brooks, Robert

    2012-01-01

    This article illustrates using carbon emissions data in an introductory statistics assignment. The carbon emissions data has desirable characteristics including: choice of measure; skewness; and outliers. These complexities allow research and public policy debate to be introduced. (Contains 4 figures and 2 tables.)

  8. Effect of natural compounds on reducing formaldehyde emission from plywood

    NASA Astrophysics Data System (ADS)

    Uchiyama, Shigehisa; Matsushima, Erica; Kitao, Nahoko; Tokunaga, Hiroshi; Ando, Masanori; Otsubo, Yasufumi

    The effects of natural compounds on reducing formaldehyde emission from plywood were investigated. Urea, catechin and vanillin were examined as the natural formaldehyde reducers. The microemission cell, with an internal volume of 35 ml, the maximum exposed test surface area of 177 cm 2 and an air purge flow rate of 50 ml min -1, was used to measure specific emission rate (SER). In the case of no reducer treatment, formaldehyde emission from plywood was fast and SERs were 4.4 mg m -2 h -1 at 30 °C and 15 mg m -2 h -1 at 60 °C. When this plywood was treated with the natural compounds, the SERs of formaldehyde were decreased at all temperatures. In the case of urea treatment, the SERs of formaldehyde decreased to 0.30 mg m -2 h -1 at 30 °C and 0.65 mg m -2 h -1 at 60 °C. When the urea treatment was applied to the inside of kitchen cabinet (made from plywood; 270 cm wide, 60 cm deep, 250 cm high), the concentration of formaldehyde was reduced substantially from 1600 to 130 μg m -3. The reducing effect of formaldehyde continued during the observation period (6 months), with a mean concentration of 100 μg m -3. Reducers in the plywood would react with released formaldehyde. Application of natural compounds such as urea, catechin and vanillin could provide a simple and effective approach for suppressing formaldehyde emission from plywood.

  9. Synthesis and field emission properties of carbon nanostructures

    NASA Astrophysics Data System (ADS)

    Hou, Kun

    This dissertation focuses on developing carbon nanostructures for application as the electron emissive material in novel back-gated triode field emission devices. The synthesis, characterization, and field emission properties of carbon nanostructures, including 1-D carbon nanofibers (CNF), 2-D carbon nanosheets (CNS), and chromium oxide coated carbon nanosheets (CrOx-CNS), are presented in this work. First, we have fabricated aligned carbon nanofiber based back-gated triode field emission devices and confirmed the operation of these devices. 1-D carbon nanofibers were directly synthesized on blank TiW substrates using direct current plasma enhanced chemical vapor deposition. It was found that the morphology of carbon nanofibers could be tuned from spaghetti-like to aligned by adjusting the applied plasma power. Field emission properties of spaghetti-like and aligned carbon nanofibers on blank TiW substrates were studied using the cartridge holder assembly. Results demonstrated that spaghetti-like carbon nanofibers had better field emission performance than aligned carbon nanofibers, however, the electrostatic simulation of the triode device demonstrated that aligned carbon nanofibers should yield the best device performance. Second, we have demonstrated that carbon nanosheets, a 2-D carbon nanostructure developed by our group, were a competitive electron emissive material for application as the cold cathode in vacuum microelectronic devices. Carbon nanosheets were synthesized on a variety of substrates, without the need for catalysts, by radio frequency plasma enhanced chemical vapor deposition. Materials characterization results revealed that carbon nanosheets consisting of vertically oriented ultra-thin graphitic sheets terminating with 1-3 graphene layers were hundreds of nanometers in length and height but less than 4 nm in thickness. By using the diode holder assembly, field emission properties of carbon nanosheets were studied from a broad perspective

  10. Sevelamer carbonate markedly reduces levothyroxine absorption.

    PubMed

    Iovino, Michele; Iovine, Nicola; Petrosino, Alfanso; Giagulli, Vito A; Licchelli, Brunella; Guastamacchia, Edoardo; Triggiani, Vincenzo

    2014-01-01

    We report the case of a young woman affected by hypothyroidism due to Hashimoto's thyroiditis, previously well compensated with a full replacement therapy (150 mcg/day of levothyroxine), presenting a clinical picture of myxedema, with a TSH=650 mU/L. Two years earlier she had started a dialysis treatment because of a chronic renal failure and had been under treatment for the last 18 months with sevelamer carbonate, a phosphate binder. No improvement of clinical conditions nor reduction in TSH serum levels was observed even on increasing the dose of levothyroxine up to 300 mcg/day, whereas euthyroidism finally restored by administering the first morning dose of sevelamer carbonate at least 4 hours after levothyroxine administration. This case shows that sevelamer carbonate, in analogy with what has been already reported for sevelamer hydrochloride, can interfere with levothyroxine absorption leading to a condition of hypothyroidism in patients previously well compensated with a given replacement dose. PMID:25183496

  11. Using Geothermal Electric Power to Reduce Carbon Footprint

    NASA Astrophysics Data System (ADS)

    Crombie, George W.

    Human activities, including the burning of fossil fuels, increase carbon dioxide levels, which contributes to global warming. The research problem of the current study examined if geothermal electric power could adequately replace fossil fuel by 2050, thus reducing the emissions of carbon dioxide while avoiding potential problems with expanding nuclear generation. The purpose of this experimental research was to explore under what funding and business conditions geothermal power could be exploited to replace fossil fuels, chiefly coal. Complex systems theory, along with network theory, provided the theoretical foundation for the study. Research hypotheses focused on parameters, such as funding level, exploration type, and interfaces with the existing power grid that will bring the United States closest to the goal of phasing out fossil based power by 2050. The research was conducted by means of computer simulations, using agent-based modeling, wherein data were generated and analyzed. The simulations incorporated key information about the location of geothermal resources, exploitation methods, transmission grid limits and enhancements, and demand centers and growth. The simulation suggested that rapid and aggressive deployment of geothermal power plants in high potential areas, combined with a phase out of coal and nuclear plants, would produce minimal disruptions in the supply of electrical power in the United States. The implications for social change include reduced risk of global warming for all humans on the planet, reduced pollution due to reduction or elimination of coal and nuclear power, increased stability in energy supply and prices in the United States, and increased employment of United States citizens in jobs related to domestic energy production.

  12. Energy use and carbon emissions: Non-OECD countries

    SciTech Connect

    Not Available

    1994-12-01

    This report surveys world energy use and carbon emissions patterns, with particular emphasis on the non-OECD countries. The non OECD is important not only because it currently makes up 84% of world population, but because its energy consumption, carbon emissions, population, and grow domestic product have all been growing faster than OECD`s. This presentation has seven major sections: (1) overview of key trends in non-OECD energy use and carbon emissions since 1970; (2) Comparison and contrasting energy use and carbon emissions for five major non OEDC regions (former Soviet Union and eastern Europe, Pacific Rim including China, Latin America, other Asia; Africa; 3-7) presentation of aggregate and sectoral energy use and carbon emissions data for countries within each of the 5 regions.

  13. Reducing dust emissions at OAO Alchevskkoks coke battery 10A

    SciTech Connect

    T.F. Trembach; E.N. Lanina

    2009-07-15

    Coke battery 10A with rammed batch is under construction at OAO Alchevskkoks. The design documentation developed by Giprokoks includes measures for reducing dust emissions to the atmosphere. Aspiration systems with dry dust trapping are employed in the new components of coke battery 10A and in the existing coke-sorting equipment. Two-stage purification of dusty air in cyclones and bag filters is employed for the coke-sorting equipment. This system considerably reduces coke-dust emissions to the atmosphere.

  14. Reducing Greenhouse Gas Emissions from Agricultural Wetlands in Borneo

    NASA Astrophysics Data System (ADS)

    Abdul, H.; Fatah, L.; Nursyamsi, D.; Kazuyuki, I.

    2011-12-01

    At the forum G20 meeting in 2009, Indonesian President delivered Indonesia's commitment to reduce national greenhouse gas (GHG) emissions by 26% in 2020 by unilateral action and by 41% with support of other countries. To achieve the target, Indonesian government has put forestry, agriculture (including peatlands), energy, industry and transportation as main responsible sectors. Development of crop with low GHG emissions, increasing C sequestration and the use of organic fertilizers are among the activities to be carried out in 2010-2020 period to minimize GHG emissions from agricultural sectors. Three experiments have been carried out to elucidate the reflectivity of crop selection, soil ameliorants and organic fertilizers on GHG emissions from agricultural wetlands in Borneo. Firstly, gas samples were collected in weekly basis from oil palm, paddy, and vegetables fields and analyzed for methane (CH4) and nitrous oxide (N2O) concentrations by a gas chromatography. Secondly, coal fly ash, dolomite and ZnSO4 were incorporated into a pot containing peat and/or alluvial soils taken from wetlands in South Kalimantan. The air samples were taken and analyzed for CH4 by a gas chromatography. Finally, microbial consortium are isolated from soil, sediment and cow dung. The microbes were then propagated and used in a rice straw composting processes. The CO2, CH4 and N2O emissions from composting vessel were measured at one, two and four weeks of composting processes. The results showed that shifting the use of peatlands for oil palm to vegetable field reduced the GHG emissions by about 74% and that to paddy field reduce the GHG emissions by about 82%. The CH4 emissions from paddy field can be further reduced by applying dolomite. However, the use of coal fly ash and ZnSO4 increased CH4 emissions from peat soil cultivated to rice. The use of microbe isolated from saline soil could reduce GHG emissions during the composting of rice straw. The social aspect of GHG reduction in

  15. Century-scale patterns and trends of global pyrogenic carbon emissions and fire influences on terrestrial carbon balance

    NASA Astrophysics Data System (ADS)

    Yang, Jia; Tian, Hanqin; Tao, Bo; Ren, Wei; Lu, Chaoqun; Pan, Shufen; Wang, Yuhang; Liu, Yongqiang

    2015-09-01

    Fires have consumed a large amount of terrestrial organic carbon and significantly influenced terrestrial ecosystems and the physical climate system over the past century. Although biomass burning has been widely investigated at a global level in recent decades via satellite observations, less work has been conducted to examine the century-scale changes in global fire regimes and fire influences on the terrestrial carbon balance. In this study, we investigated global pyrogenic carbon emissions and fire influences on the terrestrial carbon fluxes from 1901 to 2010 by using a process-based land ecosystem model. Our results show a significant declining trend in global pyrogenic carbon emissions between the early 20th century and the mid-1980s but a significant upward trend between the mid-1980s and the 2000s as a result of more frequent fires in ecosystems with high carbon storage, such as peatlands and tropical forests. Over the past 110 years, average pyrogenic carbon emissions were estimated to be 2.43 Pg C yr-1 (1 Pg = 1015 g), and global average combustion rate (defined as carbon emissions per unit area burned) was 537.85 g C m-2 burned area. Due to the impacts of fires, the net primary productivity and carbon sink of global terrestrial ecosystems were reduced by 4.14 Pg C yr-1 and 0.57 Pg C yr-1, respectively. Our study suggests that special attention should be paid to fire activities in the peatlands and tropical forests in the future. Practical management strategies, such as minimizing forest logging and reducing the rate of cropland expansion in the humid regions, are in need to reduce fire risk and mitigate fire-induced greenhouse gases emissions.

  16. Effectiveness of US state policies in reducing CO2 emissions from power plants

    NASA Astrophysics Data System (ADS)

    Grant, Don; Bergstrand, Kelly; Running, Katrina

    2014-11-01

    President Obama's landmark initiative to reduce the CO2 emissions of existing power plants, the nation's largest source of greenhouse gas (GHG) pollutants, depends heavily on states and their ability to devise policies that meet the goals set by the Environmental Protection Agency (EPA). Under the EPA's proposed Clean Power Plan, states will be responsible for cutting power plants' carbon pollution 30% from 2005 levels by 2030. States have already adopted several policies to reduce the electricity sector's climate impact. Some of these policies focus on reducing power plants' CO2 emissions, and others address this outcome in a more roundabout fashion by encouraging energy efficiency and renewable energy. However, it remains unclear which, if any, of these direct and indirect strategies actually mitigate plants' emissions because scholars have yet to test their effects using plant-level emission data. Here we use a newly released data source to determine whether states' policies significantly shape individual power plants' CO2 emissions. Findings reveal that certain types of direct strategy (emission caps and GHG targets) and indirect ones (public benefit funds and electric decoupling) lower plants' emissions and thus are viable building blocks of a federal climate regime.

  17. The role of carbon dioxide in ammonia emission from manure

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ammonia emission from manure is a significant loss of fixed N from agricultural systems, and contributes to air pollution and ecosystem degradation. Despite the development of numerous mathematical models for predicting ammonia emission, the interactions between carbon dioxide emission, manure pH, a...

  18. Inorganic carbon and emission of ammonia from manure

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Animal agriculture, and manure in particular, is a major source of ammonia emissions, and numerous models have been developed for predicting ammonia emission from manure. However, even the most comprehensive models are often inaccurate. Ammonia emission is complicated by volatilization of carbon dio...

  19. Pathways of human development and carbon emissions embodied in trade

    NASA Astrophysics Data System (ADS)

    Steinberger, Julia K.; Timmons Roberts, J.; Peters, Glen P.; Baiocchi, Giovanni

    2012-02-01

    It has long been assumed that human development depends on economic growth, that national economic expansion in turn requires greater energy use and, therefore, increased greenhouse-gas emissions. These interdependences are the topic of current research. Scarcely explored, however, is the impact of international trade: although some nations develop socio-economically and import high-embodied-carbon products, it is likely that carbon-exporting countries gain significantly fewer benefits. Here, we use new consumption-based measures of national carbon emissions to explore how the relationship between human development and carbon changes when we adjust national emission rates for trade. Without such adjustment of emissions, some nations seem to be getting far better development `bang' for the carbon `buck' than others, who are showing scant gains for disproportionate shares of global emissions. Adjusting for the transfer of emissions through trade explains many of these outliers, but shows that further socio-economic benefits are accruing to carbon-importing rather than carbon-exporting countries. We also find that high life expectancies are compatible with low carbon emissions but high incomes are not. Finally, we see that, despite strong international trends, there is no deterministic industrial development trajectory: there is great diversity in pathways, and national histories do not necessarily follow the global trends.

  20. Reducing transit bus emissions: Alternative fuels or traffic operations?

    NASA Astrophysics Data System (ADS)

    Alam, Ahsan; Hatzopoulou, Marianne

    2014-06-01

    In this study, we simulated the operations and greenhouse gas (GHG) emissions of transit buses along a busy corridor and quantified the effects of two different fuels (conventional diesel and compressed natural gas) as well as a set of driving conditions on emissions. Results indicate that compressed natural gas (CNG) reduces GHG emissions by 8-12% compared to conventional diesel, this reduction could increase to 16% with high levels of traffic congestion. However, the benefits of switching from conventional diesel to CNG are less apparent when the road network is uncongested. We also investigated the effects of bus operations on emissions by applying several strategies such as transit signal priority (TSP), queue jumper lanes, and relocation of bus stops. Results show that in congested conditions, TSP alone can reduce GHG emissions by 14% and when combined with improved technology; a reduction of 23% is achieved. The reduction benefits are even more apparent when other transit operational improvements are combined with TSP. Finally a sensitivity analysis was performed to investigate the effect of operational improvements on emissions under varying levels of network congestion. We observe that under “extreme congestion”, the benefits of TSP decrease.

  1. Semiconductor technology for reducing emissions and increasing efficiency

    SciTech Connect

    Duffin, B.; Frank, R.

    1997-12-31

    The cooperation and support of all industries are required to significantly impact a worldwide reduction in gaseous emissions that may contribute to climate change. Each industry also is striving to more efficiently utilize the resources that it consumes since this is both conservation for good citizenship and an intelligent approach to business. The semiconductor industry is also extremely concerned with these issues. However, semiconductor manufacturer`s products provide solutions for reduced emissions and increased efficiency in their industry, other industries and areas that can realize significant improvements through control technology. This paper will focus on semiconductor technologies of digital control, power switching and sensing to improve efficiency and reduce emissions in automotive, industrial, and office/home applications. 10 refs., 13 figs.

  2. Wellbeing impacts of city policies for reducing greenhouse gas emissions.

    PubMed

    Hiscock, Rosemary; Mudu, Pierpaolo; Braubach, Matthias; Martuzzi, Marco; Perez, Laura; Sabel, Clive

    2014-12-01

    To mitigate climate change, city authorities are developing policies in areas such as transportation, housing and energy use, to reduce greenhouse gas emissions. In addition to their effects on greenhouse gas emissions, these policies are likely to have consequences for the wellbeing of their populations for example through changes in opportunities to take physical exercise. In order to explore the potential consequences for wellbeing, we first explore what 'wellbeing' is and how it can be operationalised for urban planners. In this paper, we illustrate how wellbeing can be divided into objective and subjective aspects which can be measured quantitatively; our review of measures informs the development of a theoretical model linking wellbeing to policies which cities use to reduce greenhouse gas emissions. Finally, we discuss the extent to which the links proposed in the conceptual model are supported by the literature and how cities can assess wellbeing implications of policies. PMID:25464129

  3. Wellbeing Impacts of City Policies for Reducing Greenhouse Gas Emissions

    PubMed Central

    Hiscock, Rosemary; Mudu, Pierpaolo; Braubach, Matthias; Martuzzi, Marco; Perez, Laura; Sabel, Clive

    2014-01-01

    To mitigate climate change, city authorities are developing policies in areas such as transportation, housing and energy use, to reduce greenhouse gas emissions. In addition to their effects on greenhouse gas emissions, these policies are likely to have consequences for the wellbeing of their populations for example through changes in opportunities to take physical exercise. In order to explore the potential consequences for wellbeing, we first explore what ‘wellbeing’ is and how it can be operationalized for urban planners. In this paper, we illustrate how wellbeing can be divided into objective and subjective aspects which can be measured quantitatively; our review of measures informs the development of a theoretical model linking wellbeing to policies which cities use to reduce greenhouse gas emissions. Finally, we discuss the extent to which the links proposed in the conceptual model are supported by the literature and how cities can assess wellbeing implications of policies. PMID:25464129

  4. A strategic decision-making model considering the social costs of carbon dioxide emissions for sustainable supply chain management.

    PubMed

    Tseng, Shih-Chang; Hung, Shiu-Wan

    2014-01-15

    Incorporating sustainability into supply chain management has become a critical issue driven by pressures from governments, customers, and various stakeholder groups over the past decade. This study proposes a strategic decision-making model considering both the operational costs and social costs caused by the carbon dioxide emissions from operating such a supply chain network for sustainable supply chain management. This model was used to evaluate carbon dioxide emissions and operational costs under different scenarios in an apparel manufacturing supply chain network. The results showed that the higher the social cost rate of carbon dioxide emissions, the lower the amount of the emission of carbon dioxide. The results also suggested that a legislation that forces the enterprises to bear the social costs of carbon dioxide emissions resulting from their economic activities is an effective approach to reducing carbon dioxide emissions. PMID:24412595

  5. Attempts to Reduce NOx Exhaust Emissions by Using Reformulated Biodiesel

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two routes were investigated for reformulating soy-based biodiesel in an effort to reduce its nitrogen oxide emissions. In the first approach, methyl soyate was modified by converting a proportion of the cis-bonds in the fatty acid chains of its methyl esters to their trans isomers. In the second ...

  6. TRANSIENT SUPPRESSION PACKAGING FOR REDUCED EMISSIONS FROM ROTARY KILN INCINERATORS

    EPA Science Inventory

    Experiments were performed on a 73 kW rotary kiln incinerator simulator to determine whether innovative waste packaging designs might reduce transient emissions of products of incomplete combustion due to batch charging of containerized liquid surrogate waste compounds bound on g...

  7. Reduced Crude Protein Effects on Aerial Emissions from Swine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effect of feeding reduced crude protein (CP) diets on air emissions was evaluated using barrows fed over the course of four feeding phases: grower-1 (beginning at 24.5 kg BW), grower-2 (55.3 kg), finisher-1 (87.2 kg), and finisher-2 (111.4 kg). Pigs were offered a control diet (C), a low CP diet...

  8. An audit of the global carbon budget: identifying and reducing sources of uncertainty

    NASA Astrophysics Data System (ADS)

    Ballantyne, A. P.; Tans, P. P.; Marland, G.; Stocker, B. D.

    2012-12-01

    Uncertainties in our carbon accounting practices may limit our ability to objectively verify emission reductions on regional scales. Furthermore uncertainties in the global C budget must be reduced to benchmark Earth System Models that incorporate carbon-climate interactions. Here we present an audit of the global C budget where we try to identify sources of uncertainty for major terms in the global C budget. The atmospheric growth rate of CO2 has increased significantly over the last 50 years, while the uncertainty in calculating the global atmospheric growth rate has been reduced from 0.4 ppm/yr to 0.2 ppm/yr (95% confidence). Although we have greatly reduced global CO2 growth rate uncertainties, there remain regions, such as the Southern Hemisphere, Tropics and Arctic, where changes in regional sources/sinks will remain difficult to detect without additional observations. Increases in fossil fuel (FF) emissions are the primary factor driving the increase in global CO2 growth rate; however, our confidence in FF emission estimates has actually gone down. Based on a comparison of multiple estimates, FF emissions have increased from 2.45 ± 0.12 PgC/yr in 1959 to 9.40 ± 0.66 PgC/yr in 2010. Major sources of increasing FF emission uncertainty are increased emissions from emerging economies, such as China and India, as well as subtle differences in accounting practices. Lastly, we evaluate emission estimates from Land Use Change (LUC). Although relative errors in emission estimates from LUC are quite high (2 sigma ~ 50%), LUC emissions have remained fairly constant in recent decades. We evaluate the three commonly used approaches to estimating LUC emissions- Bookkeeping, Satellite Imagery, and Model Simulations- to identify their main sources of error and their ability to detect net emissions from LUC.; Uncertainties in Fossil Fuel Emissions over the last 50 years.

  9. Solid state carbon nanotube device for controllable trion electroluminescence emission

    NASA Astrophysics Data System (ADS)

    Liang, Shuang; Ma, Ze; Wei, Nan; Liu, Huaping; Wang, Sheng; Peng, Lian-Mao

    2016-03-01

    Semiconducting carbon nanotubes (CNTs) have a direct chirality-dependent bandgap and reduced dimensionality-related quantum confinement effects, which are closely related to the performance of optoelectronic devices. Here, taking advantage of the large energy separations between neutral singlet excitons and charged excitons, i.e. trions in CNTs, we have achieved for the first time all trion electroluminescence (EL) emission from chirality-sorted (8,3) and (8,4) CNT-based solid state devices. We showed that strong trion emission can be obtained as a result of localized impact excitation and electrically injected holes, with an estimated efficiency of ~5 × 10-4 photons per injected hole. The importance of contact-controlled carrier injection (including symmetric and asymmetric contact configurations) and EL spectral stability for gradually increasing bias were also investigated. The realization of electrically induced pure trion emission opens up a new opportunity for CNT film-based optoelectronic devices, providing a new degree of freedom in controlling the devices to extend potential applications in spin or magnetic optoelectronics fields.Semiconducting carbon nanotubes (CNTs) have a direct chirality-dependent bandgap and reduced dimensionality-related quantum confinement effects, which are closely related to the performance of optoelectronic devices. Here, taking advantage of the large energy separations between neutral singlet excitons and charged excitons, i.e. trions in CNTs, we have achieved for the first time all trion electroluminescence (EL) emission from chirality-sorted (8,3) and (8,4) CNT-based solid state devices. We showed that strong trion emission can be obtained as a result of localized impact excitation and electrically injected holes, with an estimated efficiency of ~5 × 10-4 photons per injected hole. The importance of contact-controlled carrier injection (including symmetric and asymmetric contact configurations) and EL spectral stability for

  10. Carbon emissions reduction strategies in Africa from improved waste management: A review

    SciTech Connect

    Couth, R.; Trois, C.

    2010-11-15

    The paper summarises a literature review into waste management practices across Africa as part of a study to assess methods to reduce carbon emissions. Research shows that the average organic content for urban Municipal Solid Waste in Africa is around 56% and its degradation is a major contributor to greenhouse gas emissions. The paper concludes that the most practical and economic way to manage waste in the majority of urban communities in Africa and therefore reduce carbon emissions is to separate waste at collection points to remove dry recyclables by door to door collection, compost the remaining biogenic carbon waste in windrows, using the maturated compost as a substitute fertilizer and dispose the remaining fossil carbon waste in controlled landfills.

  11. Reducing crude protein in beef cattle diet reduces ammonia emissions from artificial feedyard surfaces.

    PubMed

    Todd, Richard W; Cole, N Andy; Clark, R Nolan

    2006-01-01

    Concentrated animal feeding operations are major sources of ammonia to the atmosphere. Control methods to reduce emissions include acidifying amendments, urease inhibitors, and absorbents. For beef cattle, decreasing crude protein (CP) in diets may be the most practical and cost-effective method to reduce ammonia emissions. Our objective was to quantify the effect of reducing CP in beef cattle diet on ammonia emissions. Two groups of steers were fed diets with either 11.5 or 13.0% CP and all urine and feces were collected. Manures from the two diet treatments were applied in a replicated laboratory chamber experiment, and ammonia emission was quantified using acid gas washing. In four seasonal field trials, manures from the two diet treatments were applied to two 10-m-diameter, circular, artificial feedyard surfaces, and ammonia emission was quantified using the integrated horizontal flux method. Manure from steers fed 11.5% CP diet had less urine, less urinary N, and a lesser fraction of total N in urine, compared with the 13.0% CP diet. Decreasing crude protein in beef cattle diets from 13 to 11.5% significantly decreased ammonia emission by 44% (p < 0.01) in the closed chamber laboratory experiment, and decreased mean daily ammonia flux by 30% (p = 0.10), 52% (p = 0.08), and 29% (p < 0.01) in summer, autumn, and spring field trials, respectively. No difference was observed in winter. On an annual basis, decreasing crude protein reduced daily ammonia flux by 28%. Reducing crude protein in beef cattle diets may provide the most practical and cost-effective way to reduce ammonia emissions from feedyards. PMID:16455840

  12. Carbon Tetrachloride Emissions from the Amazon Forest

    NASA Astrophysics Data System (ADS)

    Jardine, K.; Chambers, J. Q.; Higuchi, N.; Jardine, A. B.; Martin, S. T.; Manzi, A. O.

    2014-12-01

    As a chemically inert greenhouse gas in the troposphere with lifetimes up to 50 years but active in ozone destruction in the stratosphere, carbon tetrachloride (CCl4) plays a major role in the atmospheric chlorine budget and is widely considered strictly of anthropogenic origin deriving from numerous industrial processes and products. However, satellite remote sensing studies have shown higher concentrations at the Equator, and earlier work has suggested possible biogenic sources. Here we present highly vertically-resolved atmospheric gradients of CCl4 within and above a primary rainforest ecosystem from three towers in the Central Amazon. The observed buildup of CCl4 mixing ratios near the top of the main canopies provides new evidence for a potentially large biogenic source from the Basin. By demonstrating the need to represent tropical forests as biogenic sources of CCl4, our study may help narrow the gap between remote sensing observations of CCl4 and emission, chemistry, and transport models and therefore lead to improved predictions of its role in atmospheric chemistry and climate.

  13. Transitions in pathways of human development and carbon emissions

    NASA Astrophysics Data System (ADS)

    Lamb, W. F.; Steinberger, J. K.; Bows-Larkin, A.; Peters, G. P.; Roberts, J. T.; Wood, F. R.

    2014-01-01

    Countries are known to follow diverse pathways of life expectancy and carbon emissions, but little is known about factors driving these dynamics. In this letter we estimate the cross-sectional economic, demographic and geographic drivers of consumption-based carbon emissions. Using clustering techniques, countries are grouped according to their drivers, and analysed with respect to a criteria of one tonne of carbon emissions per capita and a life expectancy over 70 years (Goldemberg’s Corner). Five clusters of countries are identified with distinct drivers and highly differentiated outcomes of life expectancy and carbon emissions. Representatives from four clusters intersect within Goldemberg’s Corner, suggesting diverse combinations of drivers may still lead to sustainable outcomes, presenting many countries with an opportunity to follow a pathway towards low-carbon human development. By contrast, within Goldemberg’s Corner, there are no countries from the core, wealthy consuming nations. These results reaffirm the need to address economic inequalities within international agreements for climate mitigation, but acknowledge plausible and accessible examples of low-carbon human development for countries that share similar underlying drivers of carbon emissions. In addition, we note differences in drivers between models of territorial and consumption-based carbon emissions, and discuss interesting exceptions to the drivers-based cluster analysis.

  14. Unsuccessful suicide by carbon monoxide: a secondary benefit of emissions control

    SciTech Connect

    Landers, D.

    1981-11-01

    Emission systems and devices are required on automobile engines to reduce air pollution problems. Catalytic converters have been used on most 1975 and newer automobiles to reduce hydrocarbon and carbon monoxide (CO) emissions to a value that meets the Environmental Protection Agency requirements established for 1975 and 1976. The 1980-1981 Boise, Idaho, study shows that with a functioning catalytic converter either unmeasurable or sublethal quantities of CO appear in automobile exhaust. Thus, emissions control has produced a secondary benefit in reducing the number of suicides by CO poisoning from automobile exhaust fumes.

  15. Optimization of gasoline hydrocarbon compositions for reducing exhaust emissions.

    PubMed

    Shen, Yitao; Shuai, Shijin; Wang, Jianxin; Xiao, Jianhua

    2009-01-01

    Effects of hydrocarbon compositions on raw exhaust emissions and combustion processes were studied on an engine test bench. The optimization of gasoline hydrocarbon composition was discussed. As olefins content increased from 10.0% to 25.0% in volume, the combustion duration was shortened by about 2 degree crank angle (degrees CA), and the engine-out THC emission was reduced by about 15%. On the other hand, as aromatics content changed from 35.0% to 45.0%, the engine-out NOx emissions increased by 4%. An increment in olefins content resulted in a slight increase in engine-out CO emission, while the aromatics content had little effect on engine-out total hydrocarbon (THC) and CO emissions. Over the new European driving cycle (NEDC), the THC, NOx and CO emissions of fuel with 25.0% olefins and 35.0% aromatics were about 45%, 21% and 19% lower than those of fuel with 10.0% olefins and 40.0% aromatics, respectively. The optimized gasoline compositions for new engines and new vehicles have low aromatics and high olefins contents. PMID:19999967

  16. Market-driven emissions from recovery of carbon dioxide gas.

    PubMed

    Supekar, Sarang D; Skerlos, Steven J

    2014-12-16

    This article uses a market-based allocation method in a consequential life cycle assessment (LCA) framework to estimate the environmental emissions created by recovering carbon dioxide (CO2). We find that 1 ton of CO2 recovered as a coproduct of chemicals manufacturing leads to additional greenhouse gas emissions of 147-210 kg CO2 eq , while consuming 160-248 kWh of electricity, 254-480 MJ of heat, and 1836-4027 kg of water. The ranges depend on the initial and final purity of the CO2, particularly because higher purity grades require additional processing steps such as distillation, as well as higher temperature and flow rate of regeneration as needed for activated carbon treatment and desiccant beds. Higher purity also reduces process efficiency due to increased yield losses from regeneration gas and distillation reflux. Mass- and revenue-based allocation methods used in attributional LCA estimate that recovering CO2 leads to 19 and 11 times the global warming impact estimated from a market-based allocation used in consequential LCA. PMID:25412142

  17. China's Energy and Carbon Emissions Outlook to 2050

    SciTech Connect

    Zhou, Nan; Fridley, David; McNeil, Michael; Zheng, Nina; Ke, Jing; Levine, Mark

    2011-02-15

    As a result of soaring energy demand from a staggering pace of economic expansion and the related growth of energy-intensive industry, China overtook the United States to become the world's largest contributor to CO{sub 2} emissions in 2007. At the same time, China has taken serious actions to reduce its energy and carbon intensity by setting both a short-term energy intensity reduction goal for 2006 to 2010 as well as a long-term carbon intensity reduction goal for 2020. This study presents a China Energy Outlook through 2050 that assesses the role of energy efficiency policies in transitioning China to a lower emission trajectory and meeting its intensity reduction goals. Over the past few years, LBNL has established and significantly enhanced its China End-Use Energy Model which is based on the diffusion of end-use technologies and other physical drivers of energy demand. This model presents an important new approach for helping understand China's complex and dynamic drivers of energy consumption and implications of energy efficiency policies through scenario analysis. A baseline ('Continued Improvement Scenario') and an alternative energy efficiency scenario ('Accelerated Improvement Scenario') have been developed to assess the impact of actions already taken by the Chinese government as well as planned and potential actions, and to evaluate the potential for China to control energy demand growth and mitigate emissions. In addition, this analysis also evaluated China's long-term domestic energy supply in order to gauge the potential challenge China may face in meeting long-term demand for energy. It is a common belief that China's CO{sub 2} emissions will continue to grow throughout this century and will dominate global emissions. The findings from this research suggest that this will not necessarily be the case because saturation in ownership of appliances, construction of residential and commercial floor area, roadways, railways, fertilizer use, and

  18. Invasive floating macrophytes reduce greenhouse gas emissions from a small tropical lake

    PubMed Central

    Attermeyer, K.; Flury, S.; Jayakumar, R.; Fiener, P.; Steger, K.; Arya, V.; Wilken, F.; van Geldern, R.; Premke, K.

    2016-01-01

    Floating macrophytes, including water hyacinth (Eichhornia crassipes), are dominant invasive organisms in tropical aquatic systems, and they may play an important role in modifying the gas exchange between water and the atmosphere. However, these systems are underrepresented in global datasets of greenhouse gas (GHG) emissions. This study investigated the carbon (C) turnover and GHG emissions from a small (0.6 km2) water-harvesting lake in South India and analysed the effect of floating macrophytes on these emissions. We measured carbon dioxide (CO2) and methane (CH4) emissions with gas chambers in the field as well as water C mineralization rates and physicochemical variables in both the open water and in water within stands of water hyacinths. The CO2 and CH4 emissions from areas covered by water hyacinths were reduced by 57% compared with that of open water. However, the C mineralization rates were not significantly different in the water between the two areas. We conclude that the increased invasion of water hyacinths and other floating macrophytes has the potential to change GHG emissions, a process that might be relevant in regional C budgets. PMID:26846590

  19. Invasive floating macrophytes reduce greenhouse gas emissions from a small tropical lake.

    PubMed

    Attermeyer, K; Flury, S; Jayakumar, R; Fiener, P; Steger, K; Arya, V; Wilken, F; van Geldern, R; Premke, K

    2016-01-01

    Floating macrophytes, including water hyacinth (Eichhornia crassipes), are dominant invasive organisms in tropical aquatic systems, and they may play an important role in modifying the gas exchange between water and the atmosphere. However, these systems are underrepresented in global datasets of greenhouse gas (GHG) emissions. This study investigated the carbon (C) turnover and GHG emissions from a small (0.6 km(2)) water-harvesting lake in South India and analysed the effect of floating macrophytes on these emissions. We measured carbon dioxide (CO2) and methane (CH4) emissions with gas chambers in the field as well as water C mineralization rates and physicochemical variables in both the open water and in water within stands of water hyacinths. The CO2 and CH4 emissions from areas covered by water hyacinths were reduced by 57% compared with that of open water. However, the C mineralization rates were not significantly different in the water between the two areas. We conclude that the increased invasion of water hyacinths and other floating macrophytes has the potential to change GHG emissions, a process that might be relevant in regional C budgets. PMID:26846590

  20. New technologies reduce greenhouse gas emissions from nitrogenous fertilizer in China.

    PubMed

    Zhang, Wei-Feng; Dou, Zheng-Xia; He, Pan; Ju, Xiao-Tang; Powlson, David; Chadwick, Dave; Norse, David; Lu, Yue-Lai; Zhang, Ying; Wu, Liang; Chen, Xin-Ping; Cassman, Kenneth G; Zhang, Fu-Suo

    2013-05-21

    Synthetic nitrogen (N) fertilizer has played a key role in enhancing food production and keeping half of the world's population adequately fed. However, decades of N fertilizer overuse in many parts of the world have contributed to soil, water, and air pollution; reducing excessive N losses and emissions is a central environmental challenge in the 21st century. China's participation is essential to global efforts in reducing N-related greenhouse gas (GHG) emissions because China is the largest producer and consumer of fertilizer N. To evaluate the impact of China's use of N fertilizer, we quantify the carbon footprint of China's N fertilizer production and consumption chain using life cycle analysis. For every ton of N fertilizer manufactured and used, 13.5 tons of CO2-equivalent (eq) (t CO2-eq) is emitted, compared with 9.7 t CO2-eq in Europe. Emissions in China tripled from 1980 [131 terrogram (Tg) of CO2-eq (Tg CO2-eq)] to 2010 (452 Tg CO2-eq). N fertilizer-related emissions constitute about 7% of GHG emissions from the entire Chinese economy and exceed soil carbon gain resulting from N fertilizer use by several-fold. We identified potential emission reductions by comparing prevailing technologies and management practices in China with more advanced options worldwide. Mitigation opportunities include improving methane recovery during coal mining, enhancing energy efficiency in fertilizer manufacture, and minimizing N overuse in field-level crop production. We find that use of advanced technologies could cut N fertilizer-related emissions by 20-63%, amounting to 102-357 Tg CO2-eq annually. Such reduction would decrease China's total GHG emissions by 2-6%, which is significant on a global scale. PMID:23671096

  1. New technologies reduce greenhouse gas emissions from nitrogenous fertilizer in China

    PubMed Central

    Dou, Zheng-xia; He, Pan; Ju, Xiao-Tang; Powlson, David; Chadwick, Dave; Norse, David; Lu, Yue-Lai; Zhang, Ying; Wu, Liang; Chen, Xin-Ping; Cassman, Kenneth G.; Zhang, Fu-Suo

    2013-01-01

    Synthetic nitrogen (N) fertilizer has played a key role in enhancing food production and keeping half of the world’s population adequately fed. However, decades of N fertilizer overuse in many parts of the world have contributed to soil, water, and air pollution; reducing excessive N losses and emissions is a central environmental challenge in the 21st century. China’s participation is essential to global efforts in reducing N-related greenhouse gas (GHG) emissions because China is the largest producer and consumer of fertilizer N. To evaluate the impact of China’s use of N fertilizer, we quantify the carbon footprint of China’s N fertilizer production and consumption chain using life cycle analysis. For every ton of N fertilizer manufactured and used, 13.5 tons of CO2-equivalent (eq) (t CO2-eq) is emitted, compared with 9.7 t CO2-eq in Europe. Emissions in China tripled from 1980 [131 terrogram (Tg) of CO2-eq (Tg CO2-eq)] to 2010 (452 Tg CO2-eq). N fertilizer-related emissions constitute about 7% of GHG emissions from the entire Chinese economy and exceed soil carbon gain resulting from N fertilizer use by several-fold. We identified potential emission reductions by comparing prevailing technologies and management practices in China with more advanced options worldwide. Mitigation opportunities include improving methane recovery during coal mining, enhancing energy efficiency in fertilizer manufacture, and minimizing N overuse in field-level crop production. We find that use of advanced technologies could cut N fertilizer-related emissions by 20–63%, amounting to 102–357 Tg CO2-eq annually. Such reduction would decrease China’s total GHG emissions by 2–6%, which is significant on a global scale. PMID:23671096

  2. Embodied energy consumption and carbon emissions evaluation for urban industrial structure optimization

    NASA Astrophysics Data System (ADS)

    Ji, Xi; Chen, Zhanming; Li, Jinkai

    2014-03-01

    Cities are the main material processors associated with industrialization. The development of urban production based on fossil fuels is the major contributor to the rise of greenhouse gas density, and to global warming. The concept of urban industrial structure optimization is considered to be a solution to urban sustainable development and global climate issues. Enforcing energy conservation and reducing carbon emissions are playing key roles in addressing these issues. As such, quantitative accounting and the evaluation of energy consumption and corresponding carbon emissions, which are by-products of urban production, are critical, in order to discover potential opportunities to save energy and to reduce emissions. Conventional evaluation indicators, such as "energy consumption per unit output value" and "emissions per unit output value", are concerned with immediate consumptions and emissions; while the indirect consumptions and emissions that occur throughout the supply chain are ignored. This does not support the optimization of the overall urban industrial system. To present a systematic evaluation framework for cities, this study constructs new evaluation indicators, based on the concepts of "embodied energy" and "embodied carbon emissions", which take both the immediate and indirect effects of energy consumption and emissions into account. Taking Beijing as a case, conventional evaluation indicators are compared with the newly constructed ones. Results show that the energy consumption and emissions of urban industries are represented better by the new indicators than by conventional indicators, and provide useful information for urban industrial structure optimization.

  3. Disproportionality in Power Plants’ Carbon Emissions: A Cross-National Study

    PubMed Central

    Jorgenson, Andrew; Longhofer, Wesley; Grant, Don

    2016-01-01

    Past research on the disproportionality of pollution suggests a small subset of a sector’s facilities often produces the lion’s share of toxic emissions. Here we extend this idea to the world’s electricity sectors by calculating national-level disproportionality Gini coefficients for plant-level carbon emissions in 161 nations based on data from 19,941 fossil-fuel burning power plants. We also evaluate if disproportionalities in plant-level emissions are associated with increased national carbon emissions from fossil-fuel based electricity production, while accounting for other well-established human drivers of greenhouse gas emissions. Results suggest that one potential pathway to decreasing nations’ greenhouse gas emissions could involve reducing disproportionality among fossil-fuel power plants by targeting those plants in the upper end of the distribution that burn fuels more inefficiently to produce electricity. PMID:27363677

  4. Disproportionality in Power Plants’ Carbon Emissions: A Cross-National Study

    NASA Astrophysics Data System (ADS)

    Jorgenson, Andrew; Longhofer, Wesley; Grant, Don

    2016-07-01

    Past research on the disproportionality of pollution suggests a small subset of a sector’s facilities often produces the lion’s share of toxic emissions. Here we extend this idea to the world’s electricity sectors by calculating national-level disproportionality Gini coefficients for plant-level carbon emissions in 161 nations based on data from 19,941 fossil-fuel burning power plants. We also evaluate if disproportionalities in plant-level emissions are associated with increased national carbon emissions from fossil-fuel based electricity production, while accounting for other well-established human drivers of greenhouse gas emissions. Results suggest that one potential pathway to decreasing nations’ greenhouse gas emissions could involve reducing disproportionality among fossil-fuel power plants by targeting those plants in the upper end of the distribution that burn fuels more inefficiently to produce electricity.

  5. Disproportionality in Power Plants' Carbon Emissions: A Cross-National Study.

    PubMed

    Jorgenson, Andrew; Longhofer, Wesley; Grant, Don

    2016-01-01

    Past research on the disproportionality of pollution suggests a small subset of a sector's facilities often produces the lion's share of toxic emissions. Here we extend this idea to the world's electricity sectors by calculating national-level disproportionality Gini coefficients for plant-level carbon emissions in 161 nations based on data from 19,941 fossil-fuel burning power plants. We also evaluate if disproportionalities in plant-level emissions are associated with increased national carbon emissions from fossil-fuel based electricity production, while accounting for other well-established human drivers of greenhouse gas emissions. Results suggest that one potential pathway to decreasing nations' greenhouse gas emissions could involve reducing disproportionality among fossil-fuel power plants by targeting those plants in the upper end of the distribution that burn fuels more inefficiently to produce electricity. PMID:27363677

  6. Development of Nuclear Renewable Oil Shale Systems for Flexible Electricity and Reduced Fossil Fuel Emissions

    SciTech Connect

    Daniel Curtis; Charles Forsberg; Humberto Garcia

    2015-05-01

    We propose the development of Nuclear Renewable Oil Shale Systems (NROSS) in northern Europe, China, and the western United States to provide large supplies of flexible, dispatchable, very-low-carbon electricity and fossil fuel production with reduced CO2 emissions. NROSS are a class of large hybrid energy systems in which base-load nuclear reactors provide the primary energy used to produce shale oil from kerogen deposits and simultaneously provide flexible, dispatchable, very-low-carbon electricity to the grid. Kerogen is solid organic matter trapped in sedimentary shale, and large reserves of this resource, called oil shale, are found in northern Europe, China, and the western United States. NROSS couples electricity generation and transportation fuel production in a single operation, reduces lifecycle carbon emissions from the fuel produced, improves revenue for the nuclear plant, and enables a major shift toward a very-low-carbon electricity grid. NROSS will require a significant development effort in the United States, where kerogen resources have never been developed on a large scale. In Europe, however, nuclear plants have been used for process heat delivery (district heating), and kerogen use is familiar in certain countries. Europe, China, and the United States all have the opportunity to use large scale NROSS development to enable major growth in renewable generation and either substantially reduce or eliminate their dependence on foreign fossil fuel supplies, accelerating their transitions to cleaner, more efficient, and more reliable energy systems.

  7. Reducing the spin-spin interaction of stable carbon radicals.

    PubMed

    Green, Uri; Aizenshtat, Zeev; Ruthstein, Sharon; Cohen, Haim

    2013-05-01

    We report the discovery that a flow of CO2, N2 or He can sufficiently reduce the spin-spin interactions of specific stable carbon centered radicals by displacing the molecular oxygen in the atmosphere enabling their detection via electron paramagnetic resonance (EPR). This finding unlike other reported effects on carbon radicals occurs under STP conditions and is reversible. PMID:23518921

  8. Estimated Carbon Dioxide Emissions in 2008: United States

    SciTech Connect

    Smith, C A; Simon, A J; Belles, R D

    2011-04-01

    Flow charts depicting carbon dioxide emissions in the United States have been constructed from publicly available data and estimates of state-level energy use patterns. Approximately 5,800 million metric tons of carbon dioxide were emitted throughout the United States for use in power production, residential, commercial, industrial, and transportation applications in 2008. Carbon dioxide is emitted from the use of three major energy resources: natural gas, coal, and petroleum. The flow patterns are represented in a compact 'visual atlas' of 52 state-level (all 50 states, the District of Columbia, and one national) carbon dioxide flow charts representing a comprehensive systems view of national CO{sub 2} emissions. Lawrence Livermore National Lab (LLNL) has published flow charts (also referred to as 'Sankey Diagrams') of important national commodities since the early 1970s. The most widely recognized of these charts is the U.S. energy flow chart (http://flowcharts.llnl.gov). LLNL has also published charts depicting carbon (or carbon dioxide potential) flow and water flow at the national level as well as energy, carbon, and water flows at the international, state, municipal, and organizational (i.e. United States Air Force) level. Flow charts are valuable as single-page references that contain quantitative data about resource, commodity, and byproduct flows in a graphical form that also convey structural information about the system that manages those flows. Data on carbon dioxide emissions from the energy sector are reported on a national level. Because carbon dioxide emissions are not reported for individual states, the carbon dioxide emissions are estimated using published energy use information. Data on energy use is compiled by the U.S. Department of Energy's Energy Information Administration (U.S. EIA) in the State Energy Data System (SEDS). SEDS is updated annually and reports data from 2 years prior to the year of the update. SEDS contains data on primary

  9. Solid state carbon nanotube device for controllable trion electroluminescence emission.

    PubMed

    Liang, Shuang; Ma, Ze; Wei, Nan; Liu, Huaping; Wang, Sheng; Peng, Lian-Mao

    2016-03-28

    Semiconducting carbon nanotubes (CNTs) have a direct chirality-dependent bandgap and reduced dimensionality-related quantum confinement effects, which are closely related to the performance of optoelectronic devices. Here, taking advantage of the large energy separations between neutral singlet excitons and charged excitons, i.e. trions in CNTs, we have achieved for the first time all trion electroluminescence (EL) emission from chirality-sorted (8,3) and (8,4) CNT-based solid state devices. We showed that strong trion emission can be obtained as a result of localized impact excitation and electrically injected holes, with an estimated efficiency of ∼5 × 10(-4) photons per injected hole. The importance of contact-controlled carrier injection (including symmetric and asymmetric contact configurations) and EL spectral stability for gradually increasing bias were also investigated. The realization of electrically induced pure trion emission opens up a new opportunity for CNT film-based optoelectronic devices, providing a new degree of freedom in controlling the devices to extend potential applications in spin or magnetic optoelectronics fields. PMID:26953676

  10. Deterministic Cold Cathode Electron Emission from Carbon Nanofibre Arrays

    PubMed Central

    Cole, Matthew T.; Teo, Kenneth B. K.; Groening, Oliver; Gangloff, Laurent; Legagneux, Pierre; Milne, William I.

    2014-01-01

    The ability to accurately design carbon nanofibre (CN) field emitters with predictable electron emission characteristics will enable their use as electron sources in various applications such as microwave amplifiers, electron microscopy, parallel beam electron lithography and advanced Xray sources. Here, highly uniform CN arrays of controlled diameter, pitch and length were fabricated using plasma enhanced chemical vapour deposition and their individual emission characteristics and field enhancement factors were probed using scanning anode field emission mapping. For a pitch of 10 µm and a CN length of 5 µm, the directly measured enhancement factors of individual CNs was 242, which was in excellent agreement with conventional geometry estimates (240). We show here direct empirical evidence that in regular arrays of vertically aligned CNs the overall enhancement factor is reduced when the pitch between emitters is less than half the emitter height, in accordance to our electrostatic simulations. Individual emitters showed narrow Gaussian-like field enhancement distributions, in excellent agreement with electric field simulations. PMID:24787895

  11. Deterministic cold cathode electron emission from carbon nanofibre arrays.

    PubMed

    Cole, Matthew T; Teo, Kenneth B K; Groening, Oliver; Gangloff, Laurent; Legagneux, Pierre; Milne, William I

    2014-01-01

    The ability to accurately design carbon nanofibre (CN) field emitters with predictable electron emission characteristics will enable their use as electron sources in various applications such as microwave amplifiers, electron microscopy, parallel beam electron lithography and advanced Xray sources. Here, highly uniform CN arrays of controlled diameter, pitch and length were fabricated using plasma enhanced chemical vapour deposition and their individual emission characteristics and field enhancement factors were probed using scanning anode field emission mapping. For a pitch of 10 µm and a CN length of 5 µm, the directly measured enhancement factors of individual CNs was 242, which was in excellent agreement with conventional geometry estimates (240). We show here direct empirical evidence that in regular arrays of vertically aligned CNs the overall enhancement factor is reduced when the pitch between emitters is less than half the emitter height, in accordance to our electrostatic simulations. Individual emitters showed narrow Gaussian-like field enhancement distributions, in excellent agreement with electric field simulations. PMID:24787895

  12. Energy Use and Carbon Emissions: Non-OECD Countries

    EIA Publications

    1994-01-01

    Presents world energy use and carbon emissions patterns, with particular emphasis on the non-OECD (Organization for Economic Cooperation and Development) countries (including the current and former centrally planned economies).

  13. METHOD FOR MEASURING CARBON FIBER EMISSIONS FROM STATIONARY SOURCES

    EPA Science Inventory

    Carbon fibers are highly conductive, lightweight and of small dimensions. When released as emissions from production, manufacturing, processing and disposal sources they may become airborne and disperse over wide areas. If they settle onto electronic or electrical components they...

  14. [Research on contribution decomposition by industry to China's carbon intensity reduction and carbon emission growth].

    PubMed

    Jiang, Jing-Jing; Ye, Bin; Ji, Jun-Ping; Ma, Xiao-Ming

    2014-11-01

    The binding carbon intensity index and the pilot "cap-and-trade" emission trading scheme are two important approaches currently applied by China to mitigate its greenhouse gases emissions. It is of great significance to research the influence mechanism of related factors by industry on the dynamics of national carbon intensity and emission, not only for setting industry-specified intensity reduction target but also for setting industry coverage of the ETS. Two LMDI models were applied in this paper to decompose industry contributions to the changes of China's carbon intensity and carbon emission during the period of 1996-2010. Empirical results showed that: The decline of national carbon intensity was jointly determined by the changes of carbon intensities and the added value proportions of all industries, and the impact of industry carbon intensities was larger. The increase of national carbon emission was jointly determined by the changes of carbon intensities and the added value of all industries. The former had inhibitory effect whist the latter had decisive promoting effect. The five industries making the largest contribution to the changes of national carbon emission and carbon intensity included industries of electricity, nonmetal mineral, ferrous metal, transportation service, chemical materials, which were followed by the industries of agriculture, coal mining and processing, petroleum and natural gas extraction. Petroleum refining and coking industry and construction industry made small contribution to the decline of national carbon intensity, but made large contribution to the growth of national carbon emission. The contributions of service industries to national carbon emission growth showed a rising trend, especially those of transportation service industry, wholesaling, retailing and catering service industry. PMID:25639120

  15. Method of reducing chlorofluorocarbon refrigerant emissions in the atmosphere

    SciTech Connect

    DeVault, R.C.; Fairchild, P.D.; Biermann, W.J.

    1990-06-19

    This patent describes a method of reducing escape of refrigerant emissions to the atmosphere during removal of a chlorofluorocarbon refrigerant from a vapor compression cooling system or heat pump. The method comprises contacting the chlorofluorocarbon refrigerant during removal with a sorbent material into which the chlorofluorocarbon refrigerant can be dissolved, the sorbent material being selected from the group consisting of N-methyl-2-pyrrolidone, ethyl tetrahydro furfuryl ether, tetramethylene glycol dimethylether, triethylene glycol dimethylether, N,N-dimethyl formamide, dimethylamides, and tetrachloroethane.

  16. Carbon emissions and sequestration in forests: Case studies from seven developing countries. Volume 1, Summary: Draft

    SciTech Connect

    Makundi, W.; Sathaye, J.; Cerutti, O.M.

    1992-08-01

    Forests are a major source of carbon dioxide emissions in developing countries, in most cases far exceeding the emissions from the energy sector. To date, however, efforts at quantifying forestry emissions have produced a wide range of results. In order to assist policymakers in developing measures to reduce emissions` levels and to increase carbon sequestration, the Tropical Forest Research Network (F-7) has undertaken this effort to improve the precision of emissions estimates and to identify possible response options in the forestry sector. This paper summarizes the results of one component of this work. The Tropical Forest Research Network (F-7) was established in 1990 as part of the Intergovernmental Panel on Climate Change`s (IPCC) activities in examining growing emissions of greenhouse gases and their potential impact on the global climate. Unlike past methods, this study relied on a network of participants from developing countries to prepare estimates of carbon emissions. The participating countries -- Brazil, China, India, Indonesia, Malaysia, Mexico and Thailand -- currently represent an estimated two-thirds of the annual deforestation of closed moist forests. This study gives an estimate of 837 million tonnes of carbon emissions from deforestation and logging in the F-7 countries in 1990. A proportional projection of these estimates to the tropical biome shows that the total carbon emissions are between 1.1 and 1.7 billion tonnes of carbon, with a working average of 1.4 billion tonnes per year. This work also provides estimates of emissions and uptake from China, which past studies rarely have included. This summary will be followed by individual reports by each of the participating countries, which will include detailed evaluations of possible response options. Estimates for Nigeria are also under preparation.

  17. Carbon emissions and sequestration in forests: Case studies from seven developing countries

    SciTech Connect

    Makundi, W.; Sathaye, J.; Cerutti, O.M.

    1992-08-01

    Forests are a major source of carbon dioxide emissions in developing countries, in most cases far exceeding the emissions from the energy sector. To date, however, efforts at quantifying forestry emissions have produced a wide range of results. In order to assist policymakers in developing measures to reduce emissions' levels and to increase carbon sequestration, the Tropical Forest Research Network (F-7) has undertaken this effort to improve the precision of emissions estimates and to identify possible response options in the forestry sector. This paper summarizes the results of one component of this work. The Tropical Forest Research Network (F-7) was established in 1990 as part of the Intergovernmental Panel on Climate Change's (IPCC) activities in examining growing emissions of greenhouse gases and their potential impact on the global climate. Unlike past methods, this study relied on a network of participants from developing countries to prepare estimates of carbon emissions. The participating countries -- Brazil, China, India, Indonesia, Malaysia, Mexico and Thailand -- currently represent an estimated two-thirds of the annual deforestation of closed moist forests. This study gives an estimate of 837 million tonnes of carbon emissions from deforestation and logging in the F-7 countries in 1990. A proportional projection of these estimates to the tropical biome shows that the total carbon emissions are between 1.1 and 1.7 billion tonnes of carbon, with a working average of 1.4 billion tonnes per year. This work also provides estimates of emissions and uptake from China, which past studies rarely have included. This summary will be followed by individual reports by each of the participating countries, which will include detailed evaluations of possible response options. Estimates for Nigeria are also under preparation.

  18. Derivation of burn scar depths and estimation of carbon emissions with LIDAR in Indonesian peatlands.

    PubMed

    Ballhorn, Uwe; Siegert, Florian; Mason, Mike; Limin, Suwido

    2009-12-15

    During the 1997/98 El Niño-induced drought peatland fires in Indonesia may have released 13-40% of the mean annual global carbon emissions from fossil fuels. One major unknown in current peatland emission estimations is how much peat is combusted by fire. Using a light detection and ranging data set acquired in Central Kalimantan, Borneo, in 2007, one year after the severe peatland fires of 2006, we determined an average burn scar depth of 0.33 +/- 0.18 m. Based on this result and the burned area determined from satellite imagery, we estimate that within the 2.79 million hectare study area 49.15 +/- 26.81 megatons of carbon were released during the 2006 El Niño episode. This represents 10-33% of all carbon emissions from transport for the European Community in the year 2006. These emissions, originating from a comparatively small area (approximately 13% of the Indonesian peatland area), underline the importance of peat fires in the context of green house gas emissions and global warming. In the past decade severe peat fires occurred during El Niño-induced droughts in 1997, 2002, 2004, 2006, and 2009. Currently, this important source of carbon emissions is not included in IPCC carbon accounting or in regional and global carbon emission models. Precise spatial measurements of peat combusted and potential avoided emissions in tropical peat swamp forests will also be required for future emission trading schemes in the framework of Reduced Emissions from Deforestation and Degradation in developing countries. PMID:19940252

  19. Derivation of burn scar depths and estimation of carbon emissions with LIDAR in Indonesian peatlands

    PubMed Central

    Ballhorn, Uwe; Siegert, Florian; Mason, Mike; Limin, Suwido

    2009-01-01

    During the 1997/98 El Niño-induced drought peatland fires in Indonesia may have released 13–40% of the mean annual global carbon emissions from fossil fuels. One major unknown in current peatland emission estimations is how much peat is combusted by fire. Using a light detection and ranging data set acquired in Central Kalimantan, Borneo, in 2007, one year after the severe peatland fires of 2006, we determined an average burn scar depth of 0.33 ± 0.18 m. Based on this result and the burned area determined from satellite imagery, we estimate that within the 2.79 million hectare study area 49.15 ± 26.81 megatons of carbon were released during the 2006 El Niño episode. This represents 10–33% of all carbon emissions from transport for the European Community in the year 2006. These emissions, originating from a comparatively small area (approximately 13% of the Indonesian peatland area), underline the importance of peat fires in the context of green house gas emissions and global warming. In the past decade severe peat fires occurred during El Niño-induced droughts in 1997, 2002, 2004, 2006, and 2009. Currently, this important source of carbon emissions is not included in IPCC carbon accounting or in regional and global carbon emission models. Precise spatial measurements of peat combusted and potential avoided emissions in tropical peat swamp forests will also be required for future emission trading schemes in the framework of Reduced Emissions from Deforestation and Degradation in developing countries. PMID:19940252

  20. Research developments in methods to reduce the carbon footprint of the food system: a review.

    PubMed

    Xu, Zhongyue; Sun, Da-Wen; Zeng, Xin-An; Liu, Dan; Pu, Hongbin

    2015-01-01

    Global warming is a worldwide issue with its evident impact across a wide range of systems and sectors. It is caused by a number of greenhouse gases (GHGs) emissions, in which food system has made up of a large part. Recently, reduction of GHG emissions has become an urgent issue to be resolved in the food system. Many governments and organizations are making great endeavors to alleviate the adverse effect of this phenomenon. In this review, methods to reduce the carbon footprint within the life cycle of a food system are presented from the technical, consumption behavior and environmental policies perspectives. The whole food system including raw material acquisition, processing, packaging, preservation, transportation, consumption, and disposal are covered. Improving management techniques, and adopting advanced technology and equipment are critical for every stage of a food system. Rational site selection is important to alleviate the influence of land use change. In addition, environmental choices of packaging stage, reduction in refrigeration dependence, and correct waste treatment are essential to reduce the total carbon footprint of the production. However, only technical methods cannot radically reverse the trend of climate change, as consumption behaviors present a great deal of influence over climate change. Appropriate purchase patterns and substitution within food product categories by low carbon products can reduce GHG emissions. Development of methods to calculate the carbon footprint of every kind of food and its processing technology enable people to make environmental choice. Policy can shape and cultivate the new code of consumption and influence the direction of emerging technology and science. From political perspectives, government intervention and carbon offset are common tools, especially for carbon tax and a real or implicit price of carbon. Finally, by mitigating the methodologies described above, the rate and magnitude of climate changes

  1. Reducing GHG emissions by co-utilization of coal with natural gas or biomass

    SciTech Connect

    Smith, I.M.

    2004-07-01

    Energy reserves price and security of supply issues are discussed in the context of the prospects for coal and policies to reduce greenhouse gas (GHG) emissions. Coal is projected to remain a major source of energy, with most of the demand growth in developing countries. Currently available power-generating technologies, deploying coal with natural gas or biomass, are examined. Examples of successful, partial substitution of coal by other fuels in power stations are highlighted, including the GHG emissions reductions achieved as well as the costs where available. Among various options, hybrid gasification and parallel cofiring of coal with biomass and natural gas appear to have the greatest potential to reduce GHG emissions. Much may also be achieved by cofiring, reburning, and repowering with gas turbines. The best method differs between different power systems. Co-utilization of biomass with coal is a least-cost option to reduce GHG emissions where the fuel prices are comparable, usually due to subsidies or taxes. The role of biomass is likely to increase due to greater use of subsidies, carbon taxes, and emissions trading within the context of the Kyoto Protocol. This should provide opportunities for clean coal technology transfer and diffusion, including biomass co-utilization. 32 refs., 1 fig., 3 tabs.

  2. Are emissions of black carbon from gasoline vehicles overestimated? Real-time, in situ measurement of black carbon emission factors.

    PubMed

    Wang, Yang; Xing, Zhenyu; Zhao, Shuhui; Zheng, Mei; Mu, Chao; Du, Ke

    2016-03-15

    Accurately quantifying black carbon (BC) emission factors (EFs) is a prerequisite for estimation of BC emission inventory. BC EFs determined by measuring BC at the roadside or chasing a vehicle on-road may introduce large uncertainty for low emission vehicles. In this study, BC concentrations were measured inside the tailpipe of gasoline vehicles with different engine sizes under different driving modes to determine the respective EFs. BC EFs ranged from 0.005-7.14 mg/kg-fuel under the speeds of 20-70 km/h, 0.05-28.95 mg/kg-fuel under the accelerations of 0.5-1.5m/s(2). Although the water vapor in the sampling stream could result in an average of 12% negative bias, the BC EFs are significantly lower than the published results obtained with roadside or chasing vehicle measurement. It is suggested to conduct measurement at the tailpipe of gasoline vehicles instead of in the atmosphere behind the vehicles to reduce the uncertainty from fluctuation in ambient BC concentration. PMID:26799329

  3. Lianas reduce carbon accumulation and storage in tropical forests

    PubMed Central

    van der Heijden, Geertje M. F.; Powers, Jennifer S.; Schnitzer, Stefan A.

    2015-01-01

    Tropical forests store vast quantities of carbon, account for one-third of the carbon fixed by photosynthesis, and are a major sink in the global carbon cycle. Recent evidence suggests that competition between lianas (woody vines) and trees may reduce forest-wide carbon uptake; however, estimates of the impact of lianas on carbon dynamics of tropical forests are crucially lacking. Here we used a large-scale liana removal experiment and found that, at 3 y after liana removal, lianas reduced net above-ground carbon uptake (growth and recruitment minus mortality) by ∼76% per year, mostly by reducing tree growth. The loss of carbon uptake due to liana-induced mortality was four times greater in the control plots in which lianas were present, but high variation among plots prevented a significant difference among the treatments. Lianas altered how aboveground carbon was stored. In forests where lianas were present, the partitioning of forest aboveground net primary production was dominated by leaves (53.2%, compared with 39.2% in liana-free forests) at the expense of woody stems (from 28.9%, compared with 43.9%), resulting in a more rapid return of fixed carbon to the atmosphere. After 3 y of experimental liana removal, our results clearly demonstrate large differences in carbon cycling between forests with and without lianas. Combined with the recently reported increases in liana abundance, these results indicate that lianas are an important and increasing agent of change in the carbon dynamics of tropical forests. PMID:26460031

  4. Carbon emissions in Mediterranean shrubland wildfires: An experimental approach

    NASA Astrophysics Data System (ADS)

    Garcia-Hurtado, Elisa; Pey, Jorge; Baeza, M. Jaime; Carrara, Arnaud; Llovet, Joan; Querol, Xavier; Alastuey, Andrés; Vallejo, V. Ramon

    2013-04-01

    Forest fire emissions modify the chemical composition of the atmosphere and the earth's climate system. The Ayoraburning experiment was designed to assess and quantify fire emissions from Mediterranean shrublands. A number of gaseous pollutants and particulate matter metrics (CO2, CO, CH4, PM2.5) were measured during 3 burning replicates by using real-time monitors. Quantification of carbon emissions released during the experiments showed that 71% was CO2, 26% CO, 3% CH4, and only 0.3% was particulate carbon. Emission factors obtained for CO2, CO and CH4 were 1257 ± 40, 453 ± 28 and 46 ± 12 g kg-1 dry matter, respectively, and combustion efficiencies ranged from 0.46 to 0.99. The experiments allowed the estimation of carbon emission in the different fire phases. Thus, 25% of carbon was sampled in the flaming phase and 75% of C in the smoldering phase. Current natural greenhouse gas (GHG) emission inventories in Mediterranean countries underestimate the actual emissions from forest fires since they do not consider forest shrub understory and shrublands and since they assume that the CO2 emitted is offset by forest re-growth. Our results may be used to improve current forest-fire emission inventories in southern Europe with special emphasis on shrublands.

  5. A reduced organic carbon component in martian basalts.

    PubMed

    Steele, A; McCubbin, F M; Fries, M; Kater, L; Boctor, N Z; Fogel, M L; Conrad, P G; Glamoclija, M; Spencer, M; Morrow, A L; Hammond, M R; Zare, R N; Vicenzi, E P; Siljeström, S; Bowden, R; Herd, C D K; Mysen, B O; Shirey, S B; Amundsen, H E F; Treiman, A H; Bullock, E S; Jull, A J T

    2012-07-13

    The source and nature of carbon on Mars have been a subject of intense speculation. We report the results of confocal Raman imaging spectroscopy on 11 martian meteorites, spanning about 4.2 billion years of martian history. Ten of the meteorites contain abiotic macromolecular carbon (MMC) phases detected in association with small oxide grains included within high-temperature minerals. Polycyclic aromatic hydrocarbons were detected along with MMC phases in Dar al Gani 476. The association of organic carbon within magmatic minerals indicates that martian magmas favored precipitation of reduced carbon species during crystallization. The ubiquitous distribution of abiotic organic carbon in martian igneous rocks is important for understanding the martian carbon cycle and has implications for future missions to detect possible past martian life. PMID:22628557

  6. Modification of carbon-fiber-composite surface emissivity/reflectance by high-index interference films

    NASA Astrophysics Data System (ADS)

    Pike, John N.; Matthews, Linn H.

    1997-10-01

    High strength/weight carbon fiber-reinforced composites (CFRCs) are finding applications where control of surface infrared emission or reflection is desirable. A quarter wave sputtered Ge film has been shown to reduce the normal emittance of a bismaleimide CFRC in the 8 - 14 micrometers band by 39%, with angle dependence theoretically constant out to 80% off-axis. A three-layer HLH stack is predicted to reduce emittance of less than 0.1. For thermal IR polymer curing, a single-layer coating optimizing emissivity in the polymer's absorption band while suppressing emission at longer wavelengths may yield electric power savings in the 10 - 20% range.

  7. Assessing Carbon Dioxide Emissions from Energy Use at a University

    ERIC Educational Resources Information Center

    Riddell, William; Bhatia, Krishan Kumar; Parisi, Matthew; Foote, Jessica; Imperatore, John, III

    2009-01-01

    Purpose: The purpose of this paper is to assess the carbon dioxide emissions associated with electric, HVAC, and hot water use from a US university. Design/methodology/approach: First, the total on-campus electrical, natural gas and oil consumption for an entire year was assessed. For each category of energy use, the carbon associated with…

  8. Short and Long Term Impacts of Forest Bioenergy Production on Atmospheric Carbon Dioxide Emissions

    NASA Astrophysics Data System (ADS)

    Hudiburg, T.; Law, B. E.; Luyssaert, S.; Thornton, P. E.

    2011-12-01

    Temperate forest annual net uptake of CO2 from the atmosphere is equivalent to ~16% of the annual fossil fuel emissions in the United States. Mitigation strategies to reduce emissions of carbon dioxide have lead to investigation of alternative sources of energy including forest biomass. The prospect of forest derived bioenergy has led to implementation of new forest management strategies based on the assumption that they will reduce total CO2 emissions to the atmosphere by simultaneously reducing the risk of wildfire and substituting for fossil fuels. The benefit of managing forests for bioenergy substitution of fossil fuels versus potential carbon sequestration by reducing harvest needs to be evaluated. This study uses a combination of Federal Forest Inventory data (FIA), remote sensing, and a coupled carbon-nitrogen ecosystem process model (CLM4-CN) to predict net atmospheric CO2 emissions from forest thinning for bioenergy production in Oregon under varying future management and climate scenarios. We use life-cycle assessment (LCA) incorporating both the forest and forest product sinks and sources of carbon dioxide. Future modeled results are compared with a reduced harvest scenario to determine the potential for increased carbon sequestration in forest biomass. We find that Oregon forests are a current strong sink of 7.5 ± 1.7 Tg C yr-1 or 61 g C m-2 yr-1. (NBP; NEP minus removals from fire and harvest). In the short term, we find that carbon dynamics following harvests for fire prevention and large-scale bioenergy production lead to 2-15% higher emissions over the next 20 years compared to current management, assuming 100% effectiveness of fire prevention. Given the current sink strength, analysis of the forest sector in Oregon demonstrates that increasing harvest levels by all practices above current business-as-usual levels increases CO2 emissions to the atmosphere as long as the region's sink persists. In the long-term, we find that projected changes in

  9. No tillage and liming reduce greenhouse gas emissions from poorly drained agricultural soils in Mediterranean regions.

    PubMed

    García-Marco, Sonia; Abalos, Diego; Espejo, Rafael; Vallejo, Antonio; Mariscal-Sancho, Ignacio

    2016-10-01

    No tillage (NT) has been associated to increased N2O emission from poorly drained agricultural soils. This is the case for soils with a low permeable Bt horizon, which generates a perched water layer after water addition (via rainfall or irrigation) over a long period of time. Moreover, these soils often have problems of acidity and require liming application to sustain crop productivity; changes in soil pH have large implications for the production and consumption of soil greenhouse gas (GHG) emissions. Here, we assessed in a split-plot design the individual and interactive effects of tillage practices (conventional tillage (CT) vs. NT) and liming (Ca-amendment vs. not-amendment) on N2O and CH4 emissions from poorly drained acidic soils, over a field experiment with a rainfed triticale crop. Soil mineral N concentrations, pH, temperature, moisture, water soluble organic carbon, GHG fluxes and denitrification capacity were measured during the experiment. Tillage increased N2O emissions by 68% compared to NT and generally led to higher CH4 emissions; both effects were due to the higher soil moisture content under CT plots. Under CT, liming reduced N2O emissions by 61% whereas no effect was observed under NT. Under both CT and NT, CH4 oxidation was enhanced after liming application due to decreased Al(3+) toxicity. Based on our results, NT should be promoted as a means to improve soil physical properties and concurrently reduce N2O and CH4 emissions. Raising the soil pH via liming has positive effects on crop yield; here we show that it may also serve to mitigate CH4 emissions and, under CT, abate N2O emissions. PMID:27235901

  10. Multi-layer carbon-based coatings for field emission

    DOEpatents

    Sullivan, John P.; Friedmann, Thomas A.

    1998-01-01

    A multi-layer resistive carbon film field emitter device for cold cathode field emission applications. The multi-layered film of the present invention consists of at least two layers of a conductive carbon material, preferably amorphous-tetrahedrally coordinated carbon, where the resistivities of adjacent layers differ. For electron emission from the surface, the preferred structure can be a top layer having a lower resistivity than the bottom layer. For edge emitting structures, the preferred structure of the film can be a plurality of carbon layers, where adjacent layers have different resistivities. Through selection of deposition conditions, including the energy of the depositing carbon species, the presence or absence of certain elements such as H, N, inert gases or boron, carbon layers having desired resistivities can be produced.

  11. Multi-layer carbon-based coatings for field emission

    DOEpatents

    Sullivan, J.P.; Friedmann, T.A.

    1998-10-13

    A multi-layer resistive carbon film field emitter device for cold cathode field emission applications is disclosed. The multi-layered film of the present invention consists of at least two layers of a conductive carbon material, preferably amorphous-tetrahedrally coordinated carbon, where the resistivities of adjacent layers differ. For electron emission from the surface, the preferred structure can be a top layer having a lower resistivity than the bottom layer. For edge emitting structures, the preferred structure of the film can be a plurality of carbon layers, where adjacent layers have different resistivities. Through selection of deposition conditions, including the energy of the depositing carbon species, the presence or absence of certain elements such as H, N, inert gases or boron, carbon layers having desired resistivities can be produced. 8 figs.

  12. A model of plant isoprene emission based on available reducing power captures responses to atmospheric CO₂.

    PubMed

    Morfopoulos, Catherine; Sperlich, Dominik; Peñuelas, Josep; Filella, Iolanda; Llusià, Joan; Medlyn, Belinda E; Niinemets, Ülo; Possell, Malcolm; Sun, Zhihong; Prentice, Iain Colin

    2014-07-01

    We present a unifying model for isoprene emission by photosynthesizing leaves based on the hypothesis that isoprene biosynthesis depends on a balance between the supply of photosynthetic reducing power and the demands of carbon fixation. We compared the predictions from our model, as well as from two other widely used models, with measurements of isoprene emission from leaves of Populus nigra and hybrid aspen (Populus tremula × P. tremuloides) in response to changes in leaf internal CO2 concentration (C(i)) and photosynthetic photon flux density (PPFD) under diverse ambient CO2 concentrations (C(a)). Our model reproduces the observed changes in isoprene emissions with C(i) and PPFD, and also reproduces the tendency for the fraction of fixed carbon allocated to isoprene to increase with increasing PPFD. It also provides a simple mechanism for the previously unexplained decrease in the quantum efficiency of isoprene emission with increasing C(a). Experimental and modelled results support our hypothesis. Our model can reproduce the key features of the observations and has the potential to improve process-based modelling of isoprene emissions by land vegetation at the ecosystem and global scales. PMID:24661143

  13. The effects of carbon tax on the Oregon economy and state greenhouse gas emissions

    NASA Astrophysics Data System (ADS)

    Rice, A. L.; Butenhoff, C. L.; Renfro, J.; Liu, J.

    2014-12-01

    Of the numerous mechanisms to mitigate greenhouse gas emissions on statewide, regional or national scales in the United States, a tax on carbon is perhaps one of the simplest. By taxing emissions directly, the costs of carbon emissions are incorporated into decision-making processes of market actors including consumers, energy suppliers and policy makers. A carbon tax also internalizes the social costs of climate impacts. In structuring carbon tax revenues to reduce corporate and personal income taxes, the negative incentives created by distortionary income taxes can be reduced or offset entirely. In 2008, the first carbon tax in North America across economic sectors was implemented in British Columbia through such a revenue-neutral program. In this work, we investigate the economic and environmental effects of a carbon tax in the state of Oregon with the goal of informing the state legislature, stakeholders and the public. The study investigates 70 different economic sectors in the Oregon economy and six geographical regions of the state. The economic model is built upon the Carbon Tax Analysis Model (C-TAM) to provide price changes in fuel with data from: the Energy Information Agency National Energy Modeling System (EIA-NEMS) Pacific Region Module which provides Oregon-specific energy forecasts; and fuel price increases imposed at different carbon fees based on fuel-specific carbon content and current and projected regional-specific electricity fuel mixes. CTAM output is incorporated into the Regional Economic Model (REMI) which is used to dynamically forecast economic impacts by region and industry sector including: economic output, employment, wages, fiscal effects and equity. Based on changes in economic output and fuel demand, we further project changes in greenhouse gas emissions resulting from economic activity and calculate revenue generated through a carbon fee. Here, we present results of this modeling effort under different scenarios of carbon fee and

  14. U.S. Energy-Related Carbon Dioxide Emissions

    EIA Publications

    2015-01-01

    The United States has a diverse energy landscape that is reflected in differences in state-level emissions profiles. Since 2005, energy-related carbon dioxide (CO2) emissions fell in 48 states (including the District of Columbia) and rose in 3 states. EIA's latest analysis of state-level energy-related CO2 emissions includes data in both absolute and per capita terms, including details by fuel and by sector.

  15. Field emission from hybrid diamond-like carbon and carbon nanotube composite structures.

    PubMed

    Zanin, H; May, P W; Hamanaka, M H M O; Corat, E J

    2013-12-11

    A thin diamond-like carbon (DLC) film was deposited onto a densely packed "forest" of vertically aligned multiwalled carbon nanotubes (VACNT). DLC deposition caused the tips of the CNTs to clump together to form a microstructured surface. Field-emission tests of this new composite material show the typical low threshold voltages for carbon nanotube structures (2 V μm(-1)) but with greatly increased emission current, better stability, and longer lifetime. PMID:24224845

  16. Reduced emissions from inexpensive high-sulphur coal briquettes

    SciTech Connect

    Gammage, R.B.; Wachter, E.A.; Wade, J.; Wilson, D.L.; Haas, J.W. ); Ahmad, N.; Siltain, F.; Raza, M.Z. )

    1992-01-01

    Airborne emissions were measured during the combustion of Pakistani high-sulphur coal, cold briquetted with lime and clay; comparison was made to emissions from raw coal and traditional fuels burnt in a native, mud-lined Angethi stove. Compared to raw coal, the amended coal gave fourfold reduced emission of respirable-size particles (RSP) and threefold reduced total releases of SO[sub 2]. In domestic cooking, substitution of the amended coal briquettes for traditional fuels will not worsen indoor air quality with respect to CO, SO[sub 2], NO[sub x], and RSP. The high peak amounts of CO (100--250 ppm), SO[sub 2] (2--5 ppm), and NO[sub x] (1--5 ppm) were limited to the early phase of burning. The high thermal value of the coal briquettes together with a simple briquetting technology, make this fuel an attractive energy alternative in countries that are underdeveloped, developing, or experiencing major restructuring.

  17. Reduced emissions from inexpensive high-sulphur coal briquettes

    SciTech Connect

    Gammage, R.B.; Wachter, E.A.; Wade, J.; Wilson, D.L.; Haas, J.W.; Ahmad, N.; Siltain, F.; Raza, M.Z.

    1992-12-01

    Airborne emissions were measured during the combustion of Pakistani high-sulphur coal, cold briquetted with lime and clay; comparison was made to emissions from raw coal and traditional fuels burnt in a native, mud-lined Angethi stove. Compared to raw coal, the amended coal gave fourfold reduced emission of respirable-size particles (RSP) and threefold reduced total releases of SO{sub 2}. In domestic cooking, substitution of the amended coal briquettes for traditional fuels will not worsen indoor air quality with respect to CO, SO{sub 2}, NO{sub x}, and RSP. The high peak amounts of CO (100--250 ppm), SO{sub 2} (2--5 ppm), and NO{sub x} (1--5 ppm) were limited to the early phase of burning. The high thermal value of the coal briquettes together with a simple briquetting technology, make this fuel an attractive energy alternative in countries that are underdeveloped, developing, or experiencing major restructuring.

  18. Carbon dioxide emissions from international air freight

    NASA Astrophysics Data System (ADS)

    Howitt, Oliver J. A.; Carruthers, Michael A.; Smith, Inga J.; Rodger, Craig J.

    2011-12-01

    Greenhouse gas emissions from international air transport were excluded from reduction targets under the Kyoto Protocol, partly because of difficulties with quantifying and apportioning such emissions. Although there has been a great deal of recent research into calculating emissions from aeroplane operations globally, publicly available emissions factors for air freight emissions are scarce. This paper presents a methodology to calculate the amount of fuel burnt and the resulting CO 2 emissions from New Zealand's internationally air freighted imports and exports in 2007. This methodology could be applied to other nations and/or regions. Using data on fuel uplift, air freight and air craft movements, and assumptions on mean passenger loadings and the mass of passengers and air freight, CO 2 emissions factors of 0.82 kg CO 2 per t-km and 0.69 kg CO 2 per t-km for short-haul and long-haul journeys, respectively, were calculated. The total amount of fuel consumed for the international air transport of New Zealand's imports and exports was calculated to be 0.21 Mt and 0.17 Mt respectively, with corresponding CO 2 emissions of 0.67 Mt and 0.53 Mt.

  19. Optimizing Technology to Reduce Mercury and Acid Gas Emissions from Electric Power Plants

    SciTech Connect

    Jeffrey C. Quick; David E. Tabet; Sharon Wakefield; Roger L. Bon

    2005-01-31

    Revised maps and associated data show potential mercury, sulfur, and chlorine emissions for U.S. coal by county of origin. Existing coal mining and coal washing practices result in a 25% reduction of mercury in U.S. coal before it is delivered to the power plant. Selection of low-mercury coal is a good mercury control option for plants having hot-side ESP, cold-side ESP, or hot-side ESP/FGD emission controls. Chlorine content is more important for plants having cold-side ESP/FGD or SDA/FF controls; optimum net mercury capture is indicated where chlorine is between 500 and 1000 ppm. Selection of low-sulfur coal should improve mercury capture where carbon in fly ash is used to reduce mercury emissions.

  20. Energy use and carbon dioxide emissions in the steel sector in key developing countries

    SciTech Connect

    Price, L.K.; Phylipsen, G.J.M.; Worrell, E.

    2001-04-01

    Iron and steel production consumes enormous quantities of energy, especially in developing countries where outdated, inefficient technologies are still used to produce iron and steel. Carbon dioxide emissions from steel production, which range between 5 and 15% of total country emissions in key developing countries (Brazil, China, India, Mexico, and South Africa), will continue to grow as these countries develop and as demand for steel products such as materials, automobiles, and appliances increases. In this report, we describe the key steel processes, discuss typical energy-intensity values for these processes, review historical trends in iron and steel production by process in five key developing countries, describe the steel industry in each of the five key developing countries, present international comparisons of energy use and carbon dioxide emissions among these countries, and provide our assessment of the technical potential to reduce these emissions based on best-practice benchmarking. Using a best practice benchmark, we find that significant savings, in the range of 33% to 49% of total primary energy used to produce steel, are technically possible in these countries. Similarly, we find that the technical potential for reducing intensities of carbon dioxide emissions ranges between 26% and 49% of total carbon dioxide emissions from steel production in these countries.

  1. Potential options to reduce GHG emissions in Venezuela

    SciTech Connect

    Pereira, N.; Bonduki, Y.; Perdomo, M.

    1996-12-31

    The Government of Venezuela ratified the United Nations Framework Convention on Climate Change (UNFCCC) in December, 1994. The Convention requires all parties to develop and publish national inventories of anthropogenic greenhouse gas emissions (GHG) as well as national plans to reduce or control emissions, taking into account their common but differentiated responsibilities and their specific national and regional development priorities, objectives, and circumstances. Within this context, the Ministry of Environment and Renewable Natural Resources and the Ministry of Energy and Mines developed the `Venezuelan Case-Study to Address Climate Change`. The study was initiated in October 1993, with the financial and technical assistance of the Government of United States, through the U.S. Country Studies Program (USCSP), and the Global Environment Facility (GEF), through the United Nations Environment Programme (UNEP).

  2. Waste management activities and carbon emissions in Africa

    SciTech Connect

    Couth, R.; Trois, C.

    2011-01-15

    This paper summarizes research into waste management activities and carbon emissions from territories in sub-Saharan Africa with the main objective of quantifying emission reductions (ERs) that can be gained through viable improvements to waste management in Africa. It demonstrates that data on waste and carbon emissions is poor and generally inadequate for prediction models. The paper shows that the amount of waste produced and its composition are linked to national Gross Domestic Product (GDP). Waste production per person is around half that in developed countries with a mean around 230 kg/hd/yr. Sub-Saharan territories produce waste with a biogenic carbon content of around 56% (+/-25%), which is approximately 40% greater than developed countries. This waste is disposed in uncontrolled dumps that produce large amounts of methane gas. Greenhouse gas (GHG) emissions from waste will rise with increasing urbanization and can only be controlled through funding mechanisms from developed countries.

  3. Reducing cold-start emissions by catalytic converter thermal management

    SciTech Connect

    Burch, S D; Potter, T F; Keyser, M A; Brady, M J; Michaels, K F

    1995-01-01

    Vacuum insulation and phase-change thermal storage have been used to enhance the heat retention of a prototype catalytic converter. Storing heat in the converter between trips allows exhaust gases to be converted more quickly, significantly reducing cold-start emissions. Using a small metal hydride, the thermal conductance of the vacuum insulation can be varied continuously between 0.49 and 27 W/m{sup 2}K (R-12 to R-0.2 insulation) to prevent overheating of the catalyst. A prototype was installed in a Dodge Neon with a 2.0-liter engine. Following a standard preconditioning and a 23-hour cold soak, an FTP (Federal Test Procedure) emissions test was performed. Although exhaust temperatures during the preconditioning were not hot enough to melt the phase-change material, the vacuum insulation performed well, resulting in a converter temperature of 146{degrees}C after the 23-hour cold soak at 27{degrees}C. Compared to the same converter at ambient conditions, overall emissions of CO and HC were reduced by 52 % and 29 %, to 0.27 and 0.037 g/mile, respectively. The maximum converter temperature during the FTP cycle was 720{degrees}C. This limited testing was performed with a nearly-fresh palladium-only catalyst, but demonstrates the potential of this vacuum insulation approach for emissions reduction and thermal control. Further testing is ongoing. An initial assessment of several production issues is made, including high-volume fabrication challenges, durability, and cost.

  4. Enhanced winter soil frost reduces methane emission during the subsequent growing season in a boreal peatland.

    PubMed

    Zhao, Junbin; Peichl, Matthias; Nilsson, Mats B

    2016-02-01

    Winter climate change may result in reduced snow cover and could, consequently, alter the soil frost regime and biogeochemical processes underlying the exchange of methane (CH4 ) in boreal peatlands. In this study, we investigated the short-term (1-3 years) vs. long-term (11 years) effects of intensified winter soil frost (induced by experimental snow exclusion) on CH4 exchange during the following growing season in a boreal peatland. In the first 3 years (2004-2006), lower CH4 emissions in the treatment plots relative to the control coincided with delayed soil temperature increase in the treatment plots at the beginning of the growing season (May). After 11 treatment years (in 2014), CH4 emissions were lower in the treatment plots relative to the control over the entire growing season, resulting in a reduction in total growing season CH4 emission by 27%. From May to July 2014, reduced sedge leaf area coincided with lower CH4 emissions in the treatment plots compared to the control. From July to August, lower dissolved organic carbon concentrations in the pore water of the treatment plots explained 72% of the differences in CH4 emission between control and treatment. In addition, greater Sphagnum moss growth in the treatment plots resulted in a larger distance between the moss surface and the water table (i.e., increasing the oxic layer) which may have enhanced the CH4 oxidation potential in the treatment plots relative to the control in 2014. The differences in vegetation might also explain the lower temperature sensitivity of CH4 emission observed in the treatment plots relative to the control. Overall, this study suggests that greater soil frost, associated with future winter climate change, might substantially reduce the growing season CH4 emission in boreal peatlands through altering vegetation dynamics and subsequently causing vegetation-mediated effects on CH4 exchange. PMID:26452333

  5. A probabilistic analysis of cumulative carbon emissions and long-term planetary warming

    NASA Astrophysics Data System (ADS)

    Fyke, Jeremy; Damon Matthews, H.

    2015-11-01

    Efforts to mitigate and adapt to long-term climate change could benefit greatly from probabilistic estimates of cumulative carbon emissions due to fossil fuel burning and resulting CO2-induced planetary warming. Here we demonstrate the use of a reduced-form model to project these variables. We performed simulations using a large-ensemble framework with parametric uncertainty sampled to produce distributions of future cumulative emissions and consequent planetary warming. A hind-cast ensemble of simulations captured 1980-2012 historical CO2 emissions trends and an ensemble of future projection simulations generated a distribution of emission scenarios that qualitatively resembled the suite of Representative and Extended Concentration Pathways. The resulting cumulative carbon emission and temperature change distributions are characterized by 5-95th percentile ranges of 0.96-4.9 teratonnes C (Tt C) and 1.4 °C-8.5 °C, respectively, with 50th percentiles at 3.1 Tt C and 4.7 °C. Within the wide range of policy-related parameter combinations that produced these distributions, we found that low-emission simulations were characterized by both high carbon prices and low costs of non-fossil fuel energy sources, suggesting the importance of these two policy levers in particular for avoiding dangerous levels of climate warming. With this analysis we demonstrate a probabilistic approach to the challenge of identifying strategies for limiting cumulative carbon emissions and assessing likelihoods of surpassing dangerous temperature thresholds.

  6. Impacts of black carbon and co-pollutant emissions from transportation sector in Mexico City

    NASA Astrophysics Data System (ADS)

    Zavala, Miguel; Almanza, Victor; Garcia, Agustin; Jazcilevich, Aron; Lei, Wenfang; Molina, Luisa

    2016-04-01

    Black carbon is one of the most important short-lived climate-forcing agents, which is harmful to human health and also contributes significantly to climate change. Transportation is one of the largest sources of black carbon emissions in many megacities and urban complexes, with diesel vehicles leading the way. Both on-road and off-road vehicles can emit substantial amounts of harmful BC-containing particulate matter (PM) and are also responsible for large emissions of carbon dioxide (CO2), carbon monoxide (CO), nitrogen oxides (NOx), and many other co-emitted volatile organic compounds (VOCs). Regionally, black carbon emissions contributions from mobile sources may vary widely depending on the technical characteristics of the vehicle fleet, the quality and chemical properties of the fuels consumed, and the degree of local development and economic activities that foster wider and more frequent or intensive use of vehicles. This presentation will review and assess the emissions of black carbon from the on-road and off-road transportation sector in the Mexico City Metropolitan Area. Viable mitigation strategies, including innovative technological alternatives to reduce black carbon and co-pollutants in diesel vehicles and their impacts on climate, human health and ecosystems will be described.

  7. Solid Fuel - Oxygen Fired Combustion for Production of Nodular Reduced Iron to Reduce CO2 Emissions and Improve Energy Efficiencies

    SciTech Connect

    Donald R. Fosnacht; Richard F. Kiesel; David W. Hendrickson; David J. Englund; Iwao Iwasaki; Rodney L. Bleifuss; Mathew A. Mlinar

    2011-12-22

    The current trend in the steel industry is an increase in iron and steel produced in electric arc furnaces (EAF) and a gradual decline in conventional steelmaking from taconite pellets in blast furnaces. In order to expand the opportunities for the existing iron ore mines beyond their blast furnace customer base, a new material is needed to satisfy the market demands of the emerging steel industry while utilizing the existing infrastructure and materials handling capabilities. This demand creates opportunity to convert iron ore or other iron bearing materials to Nodular Reduced Iron (NRI) in a recently designed Linear Hearth Furnace (LHF). NRI is a metallized iron product containing 98.5 to 96.0% iron and 2.5 to 4% C. It is essentially a scrap substitute with little impurity that can be utilized in a variety of steelmaking processes, especially the electric arc furnace. The objective of this project was to focus on reducing the greenhouse gas emissions (GHG) through reducing the energy intensity using specialized combustion systems, increasing production and the use of biomass derived carbon sources in this process. This research examined the use of a solid fuel-oxygen fired combustion system and compared the results from this system with both oxygen-fuel and air-fuel combustion systems. The solid pulverized fuels tested included various coals and a bio-coal produced from woody biomass in a specially constructed pilot scale torrefaction reactor at the Coleraine Minerals Research Laboratory (CMRL). In addition to combustion, the application of bio-coal was also tested as a means to produce a reducing atmosphere during key points in the fusion process, and as a reducing agent for ore conversion to metallic iron to capture the advantage of its inherent reduced carbon footprint. The results from this study indicate that the approaches taken can reduce both greenhouse gas emissions and the associated energy intensity with the Linear Hearth Furnace process for converting

  8. Warm Spring Reduced Impact of Summer Drought on Carbon Cycling

    NASA Astrophysics Data System (ADS)

    Wolf, S.; Keenan, T. F.; Fisher, J. B.; Baldocchi, D. D.

    2014-12-01

    Drought severely impacts biosphere-atmosphere carbon and water fluxes of terrestrial ecosystems by reducing productivity, carbon uptake and water transport to the atmosphere. The 2012 US drought was among the most intense and widespread drought events in the U.S. since the 'Dust Bowl' period in the 1930s, and had devastating effects on agricultural production. In addition, 2012 was among the warmest years on record. Using eddy covariance measurements of carbon, water and energy exchange from 25 AmeriFlux sites along with remote sensing products, we show that this summer drought substantially reduced ecosystem productivity, net carbon uptake and water transport to the atmosphere. However, the warm spring with higher ecosystem productivity reduced the impact of the summer drought on annual carbon uptake. Shifts in vegetation activity during spring also triggered feedbacks that contributed to the summer heatwave. Although the drought was exceptional, 2012 was an example of what is expected in terms of future climate change - i.e. warmer temperatures all year and an increased frequency and duration of drought in summer. Understanding the response of ecosystem carbon and water cycling to drought will help to mitigate these changes, and our study provides important new insights for that.

  9. Warm Spring Reduced Impact of Summer Drought on Carbon Cycling

    NASA Astrophysics Data System (ADS)

    Wolf, Sebastian; Keenan, Trevor F.; Fisher, Joshua B.; Baldocchi, Dennis

    2015-04-01

    Drought severely impacts biosphere-atmosphere carbon and water fluxes of terrestrial ecosystems by reducing productivity, carbon uptake and water transport to the atmosphere. The 2012 US drought was among the most intense and widespread drought events in the U.S. since the 'Dust Bowl' period in the 1930s, and had devastating effects on agricultural production. In addition, 2012 was among the warmest years on record. Using eddy covariance measurements of carbon, water and energy exchange from AmeriFlux sites along with remote sensing products, we show that this summer drought substantially reduced ecosystem productivity, net carbon uptake and water transport to the atmosphere. However, the warm spring with higher ecosystem productivity reduced the impact of the summer drought on annual carbon uptake. Shifts in vegetation activity during spring also triggered feedbacks that contributed to the summer heatwave. Although the drought was exceptional, 2012 was an example of what is expected in terms of future climate change - i.e. warmer temperatures all year and an increased frequency and duration of drought in summer. Understanding the response of ecosystem carbon and water cycling to drought will help to mitigate these changes, and our study provides important new insights for that.

  10. Green emission in carbon doped ZnO films

    SciTech Connect

    Tseng, L. T.; Yi, J. B. Zhang, X. Y.; Xing, G. Z.; Luo, X.; Li, S.; Fan, H. M.; Herng, T. S.; Ding, J.; Ionescu, M.

    2014-06-15

    The emission behavior of C-doped ZnO films, which were prepared by implantation of carbon into ZnO films, is investigated. Orange/red emission is observed for the films with the thickness of 60–100 nm. However, the film with thickness of 200 nm shows strong green emission. Further investigations by annealing bulk ZnO single crystals under different environments, i.e. Ar, Zn or C vapor, indicated that the complex defects based on Zn interstitials are responsible for the strong green emission. The existence of complex defects was confirmed by electron spin resonance (ESR) and low temperature photoluminescence (PL) measurement.

  11. Green emission in carbon doped ZnO films

    NASA Astrophysics Data System (ADS)

    Tseng, L. T.; Yi, J. B.; Zhang, X. Y.; Xing, G. Z.; Fan, H. M.; Herng, T. S.; Luo, X.; Ionescu, M.; Ding, J.; Li, S.

    2014-06-01

    The emission behavior of C-doped ZnO films, which were prepared by implantation of carbon into ZnO films, is investigated. Orange/red emission is observed for the films with the thickness of 60-100 nm. However, the film with thickness of 200 nm shows strong green emission. Further investigations by annealing bulk ZnO single crystals under different environments, i.e. Ar, Zn or C vapor, indicated that the complex defects based on Zn interstitials are responsible for the strong green emission. The existence of complex defects was confirmed by electron spin resonance (ESR) and low temperature photoluminescence (PL) measurement.

  12. Enhanced field emission from reduced graphene oxide polymer composites.

    PubMed

    Viskadouros, Georgios M; Stylianakis, Minas M; Kymakis, Emmanuel; Stratakis, Emmanuel

    2014-01-01

    Results on electron field emission (FE) from reduced graphene oxide (rGO):poly(3-hexylthiophene) (P3HT) composite layers are presented. Three different FE cathodes were tested and compared: rGO layers on (a) n(+)-Si, (b) composite films with different rGO:P3HT ratios, (c) rGO layers on composite films with different rGO:P3HT ratios. Experiments show that there is a critical rGO:P3HT ratio in which the field-emission performance is remarkably improved. Notably, such performance is always superior to that of the optimum rGO/n(+)-Si cathode. On the contrary, it is inferior to that attained upon deposition of a second rGO layer on top of the rGO:P3HT composite showed the best FE performance that showed turn-on field of as low as ~0.9 V/μm and field enhancement factor of ~1900. The contributions of the composite film morphology as well as the role of rGO sheet-substrate interaction on the emission performance are evaluated and discussed. PMID:24320752

  13. Very Stable Electron Field Emission From Strontium Titanate Coated Carbon Nanotube Matrices With Low Emission Thresholds

    SciTech Connect

    Pandey, Archana; Prasad, Abhishek; Moscatello, Jason; Engelhard, Mark H.; Wang, Chong M.; Yap, Yoke K.

    2013-01-22

    PMMA-STO-CNT matrices were created by opened-tip vertically-aligned multiwalled carbon nanotubes (VA-MWCNTs) with conformal coating of strontium titanate and Poly(methyl methacrylate). Emission threshold of 0.8 V/μm was demonstrated, about five-fold lower than that of the as-grown VAMWCNTs. Theoretical simulation and modeling suggest that PMMA-STO-CNT matrices have suppressed screening effects and Coulombs’ repulsion forces between electrons in adjacent CNTs, leading to low emission threshold, high emission density, and prolong emission stability. These findings are important for practical application of VA-MWCNTs in field emission devices.

  14. [Carbon capture and storage (CCS) and its potential role to mitigate carbon emission in China].

    PubMed

    Chen, Wen-Ying; Wu, Zong-Xin; Wang, Wei-Zhong

    2007-06-01

    Carbon capture and storage (CCS) has been widely recognized as one of the options to mitigate carbon emission to eventually stabilize carbon dioxide concentration in the atmosphere. Three parts of CCS, which are carbon capture, transport, and storage are assessed in this paper, covering comparisons of techno-economic parameters for different carbon capture technologies, comparisons of storage mechanism, capacity and cost for various storage formations, and etc. In addition, the role of CCS to mitigate global carbon emission is introduced. Finally, China MARKAL model is updated to include various CCS technologies, especially indirect coal liquefaction and poly-generation technologies with CCS, in order to consider carbon emission reduction as well as energy security issue. The model is used to generate different scenarios to study potential role of CCS to mitigate carbon emissions by 2050 in China. It is concluded that application of CCS can decrease marginal abatement cost and the decrease rate can reach 45% for the emission reduction rate of 50%, and it can lessen the dependence on nuclear power development for stringent carbon constrains. Moreover, coal resources can be cleanly used for longer time with CCS, e.g., for the scenario C70, coal share in the primary energy consumption by 2050 will increase from 10% when without CCS to 30% when with CCS. Therefore, China should pay attention to CCS R&D activities and to developing demonstration projects. PMID:17674718

  15. Propagation of uncertainty in carbon emission scenarios through the global carbon cycle

    SciTech Connect

    Keller, A.A.; Goldstein, R.A. )

    1994-09-01

    The authors used the GLOCO model, which is a carbon cycling model that considers seven terrestrial biomes, two oceans and one atmosphere, to evaluate the rise in atmospheric CO[sub 2] concentration, (pCO[sub 2]) and the partitioning of carbon to the global compartments (ocean, atmosphere and terrestrial) as a function of time for a number of possible anthropogenic carbon emission scenarios, based on different energy policies as developed by the Energy Modeling Forum (EMF-12). The authors then evaluated the possible uncertainty in carbon emission scenarios and the propagation of this uncertainty in carbon emission scenarios and the propagation of this uncertainty throughout the model to obtain an envelope for the rise in pCO[sub 2]. Large fluctuations in the input signal are smoothed by the carbon cycle, resulting in more than a four-fold reduction in uncertainty in the output signal (pCO[sub 2]). In addition, they looked at the effect that other model variables have on the pCO[sub 2] envelope, specifically the ratio of carbon to nitrogen in the emissions. The carbon to nitrogen ratio (C:N) will vary throughout the next century depending on the mix on energy sources chosen. More nitrogen in the emissions can produce a cofertilization effect in the terrestrial biomes, which would lead to sequestration of additional carbon. The uncertainty in C:N will enlarge the pCO[sub 2] uncertainty envelope by up to 20 ppm.

  16. Systems accounting for energy consumption and carbon emission by building

    NASA Astrophysics Data System (ADS)

    Shao, Ling; Chen, G. Q.; Chen, Z. M.; Guo, Shan; Han, M. Y.; Zhang, Bo; Hayat, T.; Alsaedi, A.; Ahmad, B.

    2014-06-01

    The method of systems accounting for overall energy consumption and carbon emission induced by a building is illustrated in terms of a combination of process and input-output analyses with a concrete procedure to cover various material, equipment, energy and manpower inputs. A detailed case study based on raw project data in the Bill of Quantities (BOQ) is performed for the structure engineering of the landmark buildings in E-town, Beijing (Beijing Economic-Technological Development Area). Based on the embodied energy and carbon emission intensity database for the Chinese economy in 2007, the energy consumption and the carbon emission of the structure engineering of the case buildings are quantified as 4.15E+14 J and 4.83E+04 t CO2 Eq., corresponding to intensities of 6.91E+09 J/m2 and 0.81 t CO2 Eq./m2 floor area. Steel and concrete contribute respectively about 50% and 30% of the energy consumption and the carbon emission, as a result of the reinforced-concrete structure of the case buildings. Materials contribute up to about 90% of the total energy consumption and carbon emission, in contrast to manpower, energy and equipment around 8%, 1% and 0.1%, respectively.

  17. Annual Carbon Emissions from Deforestation in the Amazon Basin between 2000 and 2010

    PubMed Central

    Song, Xiao-Peng; Huang, Chengquan; Saatchi, Sassan S.; Hansen, Matthew C.; Townshend, John R.

    2015-01-01

    Reducing emissions from deforestation and forest degradation (REDD+) is considered one of the most cost-effective strategies for mitigating climate change. However, historical deforestation and emission rates―critical inputs for setting reference emission levels for REDD+―are poorly understood. Here we use multi-source, time-series satellite data to quantify carbon emissions from deforestation in the Amazon basin on a year-to-year basis between 2000 and 2010. We first derive annual deforestation indicators by using the Moderate Resolution Imaging Spectroradiometer Vegetation Continuous Fields (MODIS VCF) product. MODIS indicators are calibrated by using a large sample of Landsat data to generate accurate deforestation rates, which are subsequently combined with a spatially explicit biomass dataset to calculate committed annual carbon emissions. Across the study area, the average deforestation and associated carbon emissions were estimated to be 1.59 ± 0.25 M ha•yr−1 and 0.18 ± 0.07 Pg C•yr−1 respectively, with substantially different trends and inter-annual variability in different regions. Deforestation in the Brazilian Amazon increased between 2001 and 2004 and declined substantially afterwards, whereas deforestation in the Bolivian Amazon, the Colombian Amazon, and the Peruvian Amazon increased over the study period. The average carbon density of lost forests after 2005 was 130 Mg C•ha−1, ~11% lower than the average carbon density of remaining forests in year 2010 (144 Mg C•ha−1). Moreover, the average carbon density of cleared forests increased at a rate of 7 Mg C•ha−1•yr−1 from 2005 to 2010, suggesting that deforestation has been progressively encroaching into high-biomass lands in the Amazon basin. Spatially explicit, annual deforestation and emission estimates like the ones derived in this study are useful for setting baselines for REDD+ and other emission mitigation programs, and for evaluating the performance of such efforts

  18. Annual Carbon Emissions from Deforestation in the Amazon Basin between 2000 and 2010.

    PubMed

    Song, Xiao-Peng; Huang, Chengquan; Saatchi, Sassan S; Hansen, Matthew C; Townshend, John R

    2015-01-01

    Reducing emissions from deforestation and forest degradation (REDD+) is considered one of the most cost-effective strategies for mitigating climate change. However, historical deforestation and emission rates-critical inputs for setting reference emission levels for REDD+-are poorly understood. Here we use multi-source, time-series satellite data to quantify carbon emissions from deforestation in the Amazon basin on a year-to-year basis between 2000 and 2010. We first derive annual deforestation indicators by using the Moderate Resolution Imaging Spectroradiometer Vegetation Continuous Fields (MODIS VCF) product. MODIS indicators are calibrated by using a large sample of Landsat data to generate accurate deforestation rates, which are subsequently combined with a spatially explicit biomass dataset to calculate committed annual carbon emissions. Across the study area, the average deforestation and associated carbon emissions were estimated to be 1.59 ± 0.25 M ha•yr(-1) and 0.18 ± 0.07 Pg C•yr(-1) respectively, with substantially different trends and inter-annual variability in different regions. Deforestation in the Brazilian Amazon increased between 2001 and 2004 and declined substantially afterwards, whereas deforestation in the Bolivian Amazon, the Colombian Amazon, and the Peruvian Amazon increased over the study period. The average carbon density of lost forests after 2005 was 130 Mg C•ha(-1), ~11% lower than the average carbon density of remaining forests in year 2010 (144 Mg C•ha(-1)). Moreover, the average carbon density of cleared forests increased at a rate of 7 Mg C•ha(-1)•yr(-1) from 2005 to 2010, suggesting that deforestation has been progressively encroaching into high-biomass lands in the Amazon basin. Spatially explicit, annual deforestation and emission estimates like the ones derived in this study are useful for setting baselines for REDD+ and other emission mitigation programs, and for evaluating the performance of such efforts. PMID

  19. Sectoral roles in greenhouse gas emissions and policy implications for energy utilization and carbon emissions trading: a case study of Beijing, China.

    PubMed

    Ge, Jianping; Lei, Yalin; Xu, Qun; Wang, Xibo

    2016-01-01

    In this study, a decomposition and emissions matrix is developed to identify the roles (giver or taker) played by the sectors in the greenhouse gas emissions for the economy of Beijing in China. Our results indicate that services were the most important emitter if we consider the total (direct and indirect) emissions. In addition to Construction, Scientific studies and technical services and Finance sectors of services were the largest takers. They have a large role in boosting greenhouse gas emissions throughout the economy of Beijing. As the basis and supporter of production activities, the electricity production and the transportation sectors were the greatest givers. More emphasis should be placed on using clean energy and carbon capture and storage technologies to reduce emissions within these sectors. Based on the roles played by these sectors in greenhouse gas emissions, some policy implications were proposed for energy utilization and carbon emissions trading. PMID:27547661

  20. Accounting for Carbon Dioxide Emissions from Bioenergy Systems

    SciTech Connect

    Marland, Gregg

    2010-12-01

    Researchers have recently argued that there is a 'critical climate accounting error' and that we should say 'goodbye to carbon neutral' for bioenergy. Many other analysts have published opionions on the same topic, and the US Environmental Protection Agency posted a specific call for information. The currently burning questions for carbon accounting is how to deal with bioenergy. The questions arises because, unlike for fossil fuels, burning of biomass fuels represents part of a cycle in which combustion releases back to the atmosphere carbon that was earlier removed from the atmosphere by growing plants. In a sustainable system, plants will again remove the carbon dioxide (CO{sub 2}) from the atmosphere. Conceptually, it is clear that there are no net emissions of the greenhouse gas CO{sub 2} if biomass is harvested and combusted at the same rate that biomass grows and removes CO{sub 2} from the atmosphere. The problem lies in the fact that growth and combustion do not occur at the same time or in the same place, and our accounting system boundaries - spatial and temporal - frequently do not provide full and balanced accounting. When the first comprehensive guidelines for estimating national greenhouse gas emissions and sinks were put together by the Organization for Economic Cooperation and Development, they noted that it has been argued that CO{sub 2} emissions resulting from bioenergy consumption should not be included in a country's official emission inventory because there are no net emissions if the biomass is produced sustainably, and if the biomass is not produced sustainably, the loss of carbon will be captured as part of the accounting for emissions from land-use change. In the same philosophical vein, the Kyoto Protocol provides that emissions or sinks of CO{sub 2} from land-use change and forestry activities be measured as the 'verifiable changes in carbon stocks'. From these has grown the convention that emissions from biomass fuels are generally not

  1. Infrared emission from hydrogenated amorphous carbon and amorphous carbon grains in the interstellar medium

    NASA Technical Reports Server (NTRS)

    Duley, W. W.; Jones, A. P.; Taylor, S. D.; Williams, D. A.

    1993-01-01

    The correlations deduced by Boulanger et al. (1990) from IRAS maps of the Chamaeleon, Taurus and Ursa Major molecular cloud complexes are interpreted in terms of the evolutionary hydrogenated amorphous carbon model of interstellar dust. In particular, regions of relatively strong 12-micron emission may be regions where recently accreted carbon is being converted by ambient UV to small PAHs in situ. Regions of weak 12-micron emission are probably quiescent regions where carbon has been annealed to amorphous carbon. Observational consequences of these inferences are briefly described.

  2. Outstanding field emission properties of wet-processed titanium dioxide coated carbon nanotube based field emission devices

    SciTech Connect

    Xu, Jinzhuo; Ou-Yang, Wei Chen, Xiaohong; Guo, Pingsheng; Piao, Xianqing; Sun, Zhuo; Xu, Peng; Wang, Miao; Li, Jun

    2015-02-16

    Field emission devices using a wet-processed composite cathode of carbon nanotube films coated with titanium dioxide exhibit outstanding field emission characteristics, including ultralow turn on field of 0.383 V μm{sup −1} and threshold field of 0.657 V μm{sup −1} corresponding with a very high field enhancement factor of 20 000, exceptional current stability, and excellent emission uniformity. The improved field emission properties are attributed to the enhanced edge effect simultaneously with the reduced screening effect, and the lowered work function of the composite cathode. In addition, the highly stable electron emission is found due to the presence of titanium dioxide nanoparticles on the carbon nanotubes, which prohibits the cathode from the influence of ions and free radical created in the emission process as well as residual oxygen gas in the device. The high-performance solution-processed composite cathode demonstrates great potential application in vacuum electronic devices.

  3. Carbon stars with alpha-C:H emission

    NASA Technical Reports Server (NTRS)

    Gerbault, Florence; Goebel, John H.

    1989-01-01

    Many carbon stars in the IRS low resolution spectra (LRS) catalog were found which display emission spectra that compare favorable with the absorption spectrum of alpha-C:H. These stars have largely been classified as 4X in the LRS which has led to their interpretation by others in terms of displaying a mixture of the UIRF's 8.6 micron band and SiC at 11.5 microns. It was also found that many of these stars have a spectral upturn at 20+ microns which resembles the MgS band seen in carbon stars and planetary nebulae. It was concluded that this group of carbon stars will evolve into planetary nebulae like NGC 7027 and IC 418. In the presence of hard ultraviolet radiation the UIRF's will light up and be displayed as narrow emission bands on top of the broad alpha-C:H emission bands.

  4. Carbon monoxide emission from small galaxies

    NASA Technical Reports Server (NTRS)

    Thronson, Harley A., Jr.; Bally, John

    1987-01-01

    A search was conducted for J = 1 yields 0 CO emission from 22 galaxies, detecting half, as part of a survey to study star formation in small to medium size galaxies. Although substantial variation was found in the star formation efficiencies of the sample galaxies, there is no apparent systematic trend with galaxy size.

  5. Dielectric barrier discharge carbon atomic emission spectrometer: universal GC detector for volatile carbon-containing compounds.

    PubMed

    Han, Bingjun; Jiang, Xiaoming; Hou, Xiandeng; Zheng, Chengbin

    2014-01-01

    It was found that carbon atomic emission can be excited in low temperature dielectric barrier discharge (DBD), and an atmospheric pressure, low power consumption, and compact microplasma carbon atomic emission spectrometer (AES) was constructed and used as a universal and sensitive gas chromatographic (GC) detector for detection of volatile carbon-containing compounds. A concentric DBD device was housed in a heating box to increase the plasma operation temperature to 300 °C to intensify carbon atomic emission at 193.0 nm. Carbon-containing compounds directly injected or eluted from GC can be decomposed, atomized, and excited in this heated DBD for carbon atomic emission. The performance of this new optical detector was first evaluated by determination of a series of volatile carbon-containing compounds including formaldehyde, ethyl acetate, methanol, ethanol, 1-propanol, 1-butanol, and 1-pentanol, and absolute limits of detection (LODs) were found at a range of 0.12-0.28 ng under the optimized conditions. Preliminary experimental results showed that it provided slightly higher LODs than those obtained by GC with a flame ionization detector (FID). Furthermore, it is a new universal GC detector for volatile carbon-containing compounds that even includes those compounds which are difficult to detect by FID, such as HCHO, CO, and CO2. Meanwhile, hydrogen gas used in conventional techniques was eliminated; and molecular optical emission detection can also be performed with this GC detector for multichannel analysis to improve resolution of overlapped chromatographic peaks of complex mixtures. PMID:24328147

  6. A carbon budget of Arizona: Comparing Natural Ecosystems with Emissions from Human Activities

    NASA Astrophysics Data System (ADS)

    Ford, A. C.; Finley, B. K.; Koch, G. W.; Hungate, B. A.

    2011-12-01

    A carbon budget of Arizona was constructed to examine the potential for carbon uptake by the state's ecosystems to mitigate human-caused emissions of greenhouse gases. The NASA-CASA (Carnegie Ames Stanford Approach) carbon flux model was used to estimate annual ecosystem CO2 exchange and the State's 2006 greenhouse gas inventory provided data on emissions from transportation, industry, waste, agriculture, electricity, industrial, and residential fuel use. The net carbon flux from primary production in the eight major land resource areas in the state averaged -1.56 million metric tons of carbon (MMTC) per year between 2001 and 2004. This net uptake from the atmosphere amounts to only 1.5% of statewide anthropogenic emissions of 99 MMTCE per year. Given this large imbalance and that projected climate trends for the region are likely to reduce C stocks in the state's forest and woodland ecosystems, land management to promote ecosystem carbon uptake is not a realistic solution to mitigate Arizona's anthropogenic greenhouse gas emissions.

  7. Soil carbon sequestration and biochar as negative emission technologies.

    PubMed

    Smith, Pete

    2016-03-01

    Despite 20 years of effort to curb emissions, greenhouse gas (GHG) emissions grew faster during the 2000s than in the 1990s, which presents a major challenge for meeting the international goal of limiting warming to <2 °C relative to the preindustrial era. Most recent scenarios from integrated assessment models require large-scale deployment of negative emissions technologies (NETs) to reach the 2 °C target. A recent analysis of NETs, including direct air capture, enhanced weathering, bioenergy with carbon capture and storage and afforestation/deforestation, showed that all NETs have significant limits to implementation, including economic cost, energy requirements, land use, and water use. In this paper, I assess the potential for negative emissions from soil carbon sequestration and biochar addition to land, and also the potential global impacts on land use, water, nutrients, albedo, energy and cost. Results indicate that soil carbon sequestration and biochar have useful negative emission potential (each 0.7 GtCeq. yr(-1) ) and that they potentially have lower impact on land, water use, nutrients, albedo, energy requirement and cost, so have fewer disadvantages than many NETs. Limitations of soil carbon sequestration as a NET centre around issues of sink saturation and reversibility. Biochar could be implemented in combination with bioenergy with carbon capture and storage. Current integrated assessment models do not represent soil carbon sequestration or biochar. Given the negative emission potential of SCS and biochar and their potential advantages compared to other NETs, efforts should be made to include these options within IAMs, so that their potential can be explored further in comparison with other NETs for climate stabilization. PMID:26732128

  8. Carbon emissions from spring 1998 fires in tropical Mexico

    SciTech Connect

    Cairns, M.A.; Hao, W.M.; Alvarado, E.; Haggerty, P.K.

    1999-04-01

    The authors used NOAA-AVHRR satellite imagery, biomass density maps, fuel consumption estimates, and a carbon emission factor to estimate the total carbon (C) emissions from the Spring 1998 fires in tropical Mexico. All eight states in southeast Mexico were affected by the wildfires, although the activity was concentrated near the common border of Oaxaca, Chiapas, and Veracruz. The fires burned approximately 482,000 ha and the land use/land cover classes most extensively impacted were the tall/medium selvas (tropical evergreen forests), open/fragmented forests, and perturbed areas. The total prompt emissions were 4.6 TgC during the two-month period of the authors` study, contributing an additional 24% to the region`s average annual net C emissions from forestry and land-use change. Mexico in 1998 experienced its driest Spring since 1941, setting the stage for the widespread burning.

  9. Self-organized global control of carbon emissions

    NASA Astrophysics Data System (ADS)

    Zhao, Zhenyuan; Fenn, Daniel J.; Hui, Pak Ming; Johnson, Neil F.

    2010-09-01

    There is much disagreement concerning how best to control global carbon emissions. We explore quantitatively how different control schemes affect the collective emission dynamics of a population of emitting entities. We uncover a complex trade-off which arises between average emissions (affecting the global climate), peak pollution levels (affecting citizens’ everyday health), industrial efficiency (affecting the nation’s economy), frequency of institutional intervention (affecting governmental costs), common information (affecting trading behavior) and market volatility (affecting financial stability). Our findings predict that a self-organized free-market approach at the level of a sector, state, country or continent can provide better control than a top-down regulated scheme in terms of market volatility and monthly pollution peaks. The control of volatility also has important implications for any future derivative carbon emissions market.

  10. Improving farming practices reduces the carbon footprint of spring wheat production.

    PubMed

    Gan, Yantai; Liang, Chang; Chai, Qiang; Lemke, Reynald L; Campbell, Con A; Zentner, Robert P

    2014-01-01

    Wheat is one of the world's most favoured food sources, reaching millions of people on a daily basis. However, its production has climatic consequences. Fuel, inorganic fertilizers and pesticides used in wheat production emit greenhouse gases that can contribute negatively to climate change. It is unknown whether adopting alternative farming practices will increase crop yield while reducing carbon emissions. Here we quantify the carbon footprint of alternative wheat production systems suited to semiarid environments. We find that integrating improved farming practices (that is, fertilizing crops based on soil tests, reducing summerfallow frequencies and rotating cereals with grain legumes) lowers wheat carbon footprint effectively, averaging -256 kg CO2 eq ha(-1) per year. For each kg of wheat grain produced, a net 0.027-0.377 kg CO2 eq is sequestered into the soil. With the suite of improved farming practices, wheat takes up more CO2 from the atmosphere than is actually emitted during its production. PMID:25405548

  11. Evaluation of carbon dioxide emission control strategies in New York State. Final report, 1990--1991

    SciTech Connect

    Morris, S.C.; Lee, J.; Goldstein, G.; Hill, D.

    1992-01-01

    A MARKAL model was developed for the State of New York. It represents the state`s energy system as a set of typical technologies for generating, converting, and using energy as it evolves over a 45-year period. NYMARKAL was applied here in demonstration analyses to explore strategies to reduce CO{sub 2} emissions. NYMARKAL was installed at the State Energy Office and in the Offices of the New York Power Pool. Staff members from both organizations and other state agencies were trained in its use. Example scenarios showed that it is more difficult and more expensive to reduce carbon emissions in New York State than in the United States as a whole. Were a common carbon tax instituted, it would have less effect in New York and most carbon emissions reduction would take place elsewhere in the country where it is more cost-effective. Alternatively, were all states required to reduce CO{sub 2} emission an equal percentage (say by 20%), the cost per unit emissions reduction to New York would be much greater than in the rest of the country.

  12. Evaluation of carbon dioxide emission control strategies in New York State

    SciTech Connect

    Morris, S.C.; Lee, J.; Goldstein, G.; Hill, D.

    1992-01-01

    A MARKAL model was developed for the State of New York. It represents the state's energy system as a set of typical technologies for generating, converting, and using energy as it evolves over a 45-year period. NYMARKAL was applied here in demonstration analyses to explore strategies to reduce CO{sub 2} emissions. NYMARKAL was installed at the State Energy Office and in the Offices of the New York Power Pool. Staff members from both organizations and other state agencies were trained in its use. Example scenarios showed that it is more difficult and more expensive to reduce carbon emissions in New York State than in the United States as a whole. Were a common carbon tax instituted, it would have less effect in New York and most carbon emissions reduction would take place elsewhere in the country where it is more cost-effective. Alternatively, were all states required to reduce CO{sub 2} emission an equal percentage (say by 20%), the cost per unit emissions reduction to New York would be much greater than in the rest of the country.

  13. New York MARKAL: An evaluation of carbon dioxide emission control strategies in New York State

    SciTech Connect

    Hamilton, L.D.

    1992-12-31

    A MARKAL model was developed for the State of New York. It represents the State`s energy system as a set of typical technologies for generating, converting, and using energy as it evolves over a 45-year period. NYMARKAL was applied here in demonstration analyses to explore strategies to reduce CO2 emissions. NYMARKAL was installed at the State Energy Office and in the Offices of the New York Power Pool. Example scenarios showed that it is more difficult and more expensive to reduce carbon emissions in New York State than in the United States as a whole. Were a common carbon tax instituted, it would have less effect in New York and most carbon emissions reduction would take place elsewhere in the country where it is more cost-effective. Alternatively, were all states required to reduce CO2 emission an equal percentage (say by 20%), the cost per unit emissions reduction to New York would be much greater than in the rest of the country.

  14. Carbon emission trading system of China: a linked market vs. separated markets

    NASA Astrophysics Data System (ADS)

    Liu, Yu; Feng, Shenghao; Cai, Songfeng; Zhang, Yaxiong; Zhou, Xiang; Chen, Yanbin; Chen, Zhanming

    2013-12-01

    The Chinese government intends to upgrade its current provincial carbon emission trading pilots to a nationwide scheme by 2015. This study investigates two of scenarios: separated provincial markets and a linked inter-provincial market. The carbon abatement effects of separated and linked markets are compared using two pilot provinces of Hubei and Guangdong based on a computable general equilibrium model termed Sino-TERMCo2. Simulation results show that the linked market can improve social welfare and reduce carbon emission intensity for the nation as well as for the Hubei-Guangdong bloc compared to the separated market. However, the combined system also distributes welfare more unevenly and thus increases social inequity. On the policy ground, the current results suggest that a well-constructed, nationwide carbon market complemented with adequate welfare transfer policies can be employed to replace the current top-down abatement target disaggregation practice.

  15. Carbon-containing cathodes for enhanced electron emission

    DOEpatents

    Cao, Renyu; Pan, Lawrence; Vergara, German; Fox, Ciaran

    2000-01-01

    A cathode has electropositive atoms directly bonded to a carbon-containing substrate. Preferably, the substrate comprises diamond or diamond-like (sp.sup.3) carbon, and the electropositive atoms are Cs. The cathode displays superior efficiency and durability. In one embodiment, the cathode has a negative electron affinity (NEA). The cathode can be used for field emission, thermionic emission, or photoemission. Upon exposure to air or oxygen, the cathode performance can be restored by annealing or other methods. Applications include detectors, electron multipliers, sensors, imaging systems, and displays, particularly flat panel displays.

  16. Electricity generation: options for reduction in carbon emissions.

    PubMed

    Whittington, H W

    2002-08-15

    Historically, the bulk production of electricity has been achieved by burning fossil fuels, with unavoidable gaseous emissions, including large quantities of carbon dioxide: an average-sized modern coal-burning power station is responsible for more than 10 Mt of CO(2) each year. This paper details typical emissions from present-day power stations and discusses the options for their reduction. Acknowledging that the cuts achieved in the past decade in the UK CO(2) emissions have been achieved largely by fuel switching, the remaining possibilities offered by this method are discussed. Switching to less-polluting fossil fuels will achieve some measure of reduction, but the basic problem of CO(2) emissions continues. Of the alternatives to fossil fuels, only nuclear power represents a zero-carbon large-scale energy source. Unfortunately, public concerns over safety and radioactive waste have still to be assuaged. Other approaches include the application of improved combustion technology, the removal of harmful gases from power-station flues and the use of waste heat to improve overall power-station efficiency. These all have a part to play, but many consider our best hope for emissions reduction to be the use of renewable energy. The main renewable energy contenders are assessed in this paper and realistic estimates of the contribution that each could provide are indicated. It appears that, in the time-scale envisaged by planners for reduction in CO(2) emission, in many countries renewable energy will be unlikely to deliver. At the same time, it is worth commenting that, again in many countries, the level of penetration of renewable energy will fall short of the present somewhat optimistic targets. Of renewable options, wind energy could be used in the short to medium term to cover for thermal plant closures, but for wind energy to be successful, the network will have to be modified to cope with wind's intermittent nature. Globally, hydroelectricity is currently the

  17. RESULTS FROM THE U.S. DOE 2006 SAVE ENERGY NOW ASSESSMENT INITIATIVE: DOE's Partnership with U.S. Industry to Reduce Energy Consumption, Energy Costs, and Carbon Dioxide Emissions

    SciTech Connect

    Wright, Anthony L; Martin, Michaela A; Gemmer, Bob; Scheihing, Paul; Quinn, James

    2007-09-01

    --those that consume a total of 1 trillion British thermal units (Btu) or more annually. The approximately 6800 U.S. facilities that fall into this category collectively account for about 53% of all energy consumed by industry in the United States. The 2006 Save Energy Now energy assessments departed from earlier DOE plant assessments by concentrating solely on steam and process heating systems, which are estimated to account for approximately 74% of all natural gas use for manufacturing. The assessments also integrated a strong training component designed to teach industrial plant personnel how to use DOE's steam or process heating opportunity assessment software tools. This approach had the advantages of promoting strong buy-in of plant personnel for the assessment and its outcomes and preparing them better to independently replicate the assessment process at the company's other facilities. The Save Energy Now initiative also included provisions to help plants that applied for but did not qualify for assessments (based on the 1 trillion Btu criterion). Services offered to these plants included (1) an assessment by one of DOE's 26 university-based Industrial Assessment Centers (IACs), (2) a telephone consultation with a systems expert at the DOE's Energy Efficiency and Renewable Energy Information Center, or (3) other technical materials and services available through ITP (e.g., the Save Energy Now CD). By the end of 2006, DOE had completed all 200 of the promised assessments, identifying potential natural gas savings of more than 50 trillion Btu and energy cost savings of about $500 million. These savings, if fully implemented, could reduce CO2 emissions by 4.04 million metric tons annually. These results, along with the fact that a large percentage of U.S. energy is used by a relatively small number of very large plants, clearly suggest that assessments are an expedient and cost-effective way to significantly affect large amounts of energy use. Building on the success of

  18. The travel-related carbon dioxide emissions of atmospheric researchers

    NASA Astrophysics Data System (ADS)

    Stohl, A.

    2008-04-01

    Most atmospheric scientists agree that greenhouse gas emissions have already caused significant changes to the global climate system and that these changes will accelerate in the near future. At the same time, atmospheric scientists who - like other scientists - rely on international collaboration and information exchange travel a lot and, thereby, cause substantial emissions of carbon dioxide (CO2). In this paper, the CO2 emissions of the employees working at an atmospheric research institute (the Norwegian Institute for Air Research, NILU) caused by all types of business travel (conference visits, workshops, field campaigns, instrument maintainance, etc.) were calculated for the years 2005-2007. It is estimated that more than 90% of the emissions were caused by air travel, 3% by ground travel and 5% by hotel usage. The travel-related annual emissions were between 1.9 and 2.4 t CO2 per employee or between 3.9 and 5.5 t CO2 per scientist. For comparison, the total annual per capita CO2 emissions are 4.5 t worldwide, 1.2 t for India, 3.8 t for China, 5.9 t for Sweden and 19.1 t for Norway. The travel-related CO2 emissions of a NILU scientist, occurring in 24 days of a year on average, exceed the global average annual per capita emission. Norway's per-capita CO2 emissions are among the highest in the world, mostly because of the emissions from the oil industry. If the emissions per NILU scientist derived in this paper are taken as representative for the average Norwegian researcher, travel by Norwegian scientists would nevertheless account for a substantial 0.2% of Norway's total CO2 emissions. Since most of the travel-related emissions are due to air travel, water vapor emissions, ozone production and contrail formation further increase the relative importance of NILU's travel in terms of radiative forcing.

  19. Reducing CO2 Emissions through Lightweight Design and Manufacturing

    NASA Astrophysics Data System (ADS)

    Carruth, Mark A.; Allwood, Julian M.; Milford, Rachel L.

    2011-05-01

    To meet targeted 50% reductions in industrial CO2 emissions by 2050, demand for steel and aluminium must be cut. Many steel and aluminium products include redundant material, and the manufacturing routes to produce them use more material than is necessary. Lightweight design and optimized manufacturing processes offer a means of demand reduction, whilst creating products to perform the same service as existing ones. This paper examines two strategies for demand reduction: lightweight product design; and minimizing yield losses through the product supply chain. Possible mass savings are estimated for specific case-studies on metal-intensive products, such as I-beams and food cans. These estimates are then extrapolated to other sectors to produce a global estimate for possible demand reductions. Results show that lightweight product design may offer potential mass savings of up to 30% for some products, whilst yield in the production of others could be improved by over 20%. If these two strategies could be combined for all products, global demand for steel and aluminium would be reduced by nearly 50%. The impact of demand reduction on CO2 emissions is presented, and barriers to the adoption of new, lightweight technologies are discussed.

  20. Warm spring reduced carbon cycle impact of the 2012 US summer drought.

    PubMed

    Wolf, Sebastian; Keenan, Trevor F; Fisher, Joshua B; Baldocchi, Dennis D; Desai, Ankur R; Richardson, Andrew D; Scott, Russell L; Law, Beverly E; Litvak, Marcy E; Brunsell, Nathaniel A; Peters, Wouter; van der Laan-Luijkx, Ingrid T

    2016-05-24

    The global terrestrial carbon sink offsets one-third of the world's fossil fuel emissions, but the strength of this sink is highly sensitive to large-scale extreme events. In 2012, the contiguous United States experienced exceptionally warm temperatures and the most severe drought since the Dust Bowl era of the 1930s, resulting in substantial economic damage. It is crucial to understand the dynamics of such events because warmer temperatures and a higher prevalence of drought are projected in a changing climate. Here, we combine an extensive network of direct ecosystem flux measurements with satellite remote sensing and atmospheric inverse modeling to quantify the impact of the warmer spring and summer drought on biosphere-atmosphere carbon and water exchange in 2012. We consistently find that earlier vegetation activity increased spring carbon uptake and compensated for the reduced uptake during the summer drought, which mitigated the impact on net annual carbon uptake. The early phenological development in the Eastern Temperate Forests played a major role for the continental-scale carbon balance in 2012. The warm spring also depleted soil water resources earlier, and thus exacerbated water limitations during summer. Our results show that the detrimental effects of severe summer drought on ecosystem carbon storage can be mitigated by warming-induced increases in spring carbon uptake. However, the results also suggest that the positive carbon cycle effect of warm spring enhances water limitations and can increase summer heating through biosphere-atmosphere feedbacks. PMID:27114518

  1. Global carbon dioxide emissions from inland waters

    USGS Publications Warehouse

    Raymond, Peter A.; Hartmann, Jens; Lauerwald, Ronny; Sobek, Sebastian; McDonald, Cory P.; Hoover, Mark; Butman, David; Striegl, Rob; Mayorga, Emilio; Humborg, Christoph; Kortelainen, Pirkko; Durr, Hans H.; Meybeck, Michel; Ciais, Philippe; Guth, Peter

    2013-01-01

    Carbon dioxide (CO2) transfer from inland waters to the atmosphere, known as CO2 evasion, is a component of the global carbon cycle. Global estimates of CO2 evasion have been hampered, however, by the lack of a framework for estimating the inland water surface area and gas transfer velocity and by the absence of a global CO2 database. Here we report regional variations in global inland water surface area, dissolved CO2 and gas transfer velocity. We obtain global CO2 evasion rates of 1.8   petagrams of carbon (Pg C) per year from streams and rivers and 0.32  Pg C yr−1 from lakes and reservoirs, where the upper and lower limits are respectively the 5th and 95th confidence interval percentiles. The resulting global evasion rate of 2.1 Pg C yr−1 is higher than previous estimates owing to a larger stream and river evasion rate. Our analysis predicts global hotspots in stream and river evasion, with about 70 per cent of the flux occurring over just 20 per cent of the land surface. The source of inland water CO2 is still not known with certainty and new studies are needed to research the mechanisms controlling CO2 evasion globally.

  2. Method for reducing emissions utilizing pre-atomized fuels

    SciTech Connect

    Hayes, M.E.; Hrebenar, K.R.; Deal, J.F. III; Bolden, P.L. Jr.

    1987-05-19

    A method is described for reducing particulate emissions during combustion of a hydrocarbon with API gravity of about 20/sup 0/ API or less, viscosity of about 40,000 centipoise at 122/sup 0/F, paraffin content of about 50% by weight or less, aromatic content of about 15% by weight or greater, and asphaltene content of about 50% by weight or greater. The method comprises: emulsifying such hydrocarbon to form a hydrocarbon-in-water emulsion having a hydrocarbon water ratio from about 60:40 to about 90:10 by volume and in which emulsion the hydrocarbon has a particle size predominantly of about 50 microns in diameter or less; preheating such hydrocarbon-in-water emulsion prior to combustion; and burning such hydrocarbon-in-water emulsion.

  3. Carbon dioxide emissions in conventional and no-till corn production systems under different fertilizer management practices

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil management practices such as tillage and fertilizer application methods affect soil emissions of greenhouse gases which impacts agricultural contributions of greenhouse gases. It is important to develop and evaluate strategies for reducing soil emissions of greenhouse gases such as carbon diox...

  4. Black Carbon Emissions from Associated Natural Gas Flaring.

    PubMed

    Weyant, Cheryl L; Shepson, Paul B; Subramanian, R; Cambaliza, Maria O L; Heimburger, Alexie; McCabe, David; Baum, Ellen; Stirm, Brian H; Bond, Tami C

    2016-02-16

    Approximately 150 billion cubic meters (BCM) of natural gas is flared and vented in the world annually, emitting greenhouse gases and other pollutants with no energy benefit. About 7 BCM per year is flared in the United States, and half is from North Dakota alone. There are few emission measurements from associated gas flares and limited black carbon (BC) emission factors have been previously reported from the field. Emission plumes from 26 individual flares in the Bakken formation in North Dakota were sampled. Methane, carbon dioxide, and BC were measured simultaneously, allowing the calculation of BC mass emission factors using the carbon balance method. Particle optical absorption was measured using a three-wavelength particle soot absorption photometer (PSAP) and BC particle number and mass concentrations were measured with a single particle soot photometer. The BC emission factors varied over 2 orders of magnitude, with an average and uncertainty range of 0.14 ± 0.12 g/kg hydrocarbons in associated gas and a median of 0.07 g/kg which represents a lower bound on these measurements. An estimation of the BC emission factor derived from PSAP absorption provides an upper bound at 3.1 g/kg. These results are lower than previous estimations and laboratory measurements. The BC mass absorption cross section was 16 ± 12 m(2)/g BC at 530 nm. The average absorption Ångström exponent was 1.2 ± 0.8, suggesting that most of the light absorbing aerosol measured was black carbon and the contribution of light absorbing organic carbon was small. PMID:26764563

  5. Carbon Input and Soil Carbon Dioxide Emission Affected by Land Use and Management Practices

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Land use and management practices may influence C inputs and soil CO2 emission, a greenhouse gas responsible for global warming. Carbon inputs and soil CO2 emission were monitored from crop- and grassland with various irrigation and cropping systems from 2006 to 2008 in western North Dakota, USA. Tr...

  6. Atmospheric monitoring for fugitive emissions from geological carbon storage

    NASA Astrophysics Data System (ADS)

    Loh, Z. M.; Etheridge, D.; Luhar, A.; Leuning, R.; Jenkins, C.

    2013-12-01

    We present a multi-year record of continuous atmospheric CO2 and CH4 concentration measurements, flask sampling (for CO2, CH4, N2O, δ13CO2 and SF6) and CO2 flux measurements at the CO2CRC Otway Project (http://www.co2crc.com.au/otway/), a demonstration site for geological storage of CO2 in south-western Victoria, Australia. The measurements are used to develop atmospheric methods for operational monitoring of large scale CO2 geological storage. Characterization of emission rates ideally requires concentration measurements upwind and downwind of the source, along with knowledge of the atmospheric turbulence field. Because only a single measurement location was available for much of the measurement period, we develop techniques to filter the record and to construct a ';pseudo-upwind' measurement from our dataset. Carbon dioxide and methane concentrations were filtered based on wind direction, downward shortwave radiation, atmospheric stability and hour-to-hour changes in CO2 flux. These criteria remove periods of naturally high concentration due to the combined effects of biogenic respiration, stable atmospheric conditions and pre-existing sources (both natural and anthropogenic), leaving a reduced data set, from which a fugitive leak from the storage reservoir, the ';(potential) source sector)', could more easily be detected. Histograms of the filtered data give a measure of the background variability in both CO2 and CH4. Comparison of the ';pseudo-upwind' dataset histogram with the ';(potential) source sector' histogram shows no statistical difference, placing limits on leakage to the atmosphere over the preceding two years. For five months in 2011, we ran a true pair of up and downwind CO2 and CH4 concentration measurements. During this period, known rates of gas were periodically released at the surface (near the original injection point). These emissions are clearly detected as elevated concentrations of CO2 and CH4 in the filtered data and in the measured

  7. Options for lowering U.S. carbon dioxide emissions

    NASA Astrophysics Data System (ADS)

    Bierbaum, Rosina M.; Friedman, Robert M.; Levenson, Howard; Rapoport, Richard D.; Sundt, Nick

    1992-03-01

    The United States can decrease its emissions of carbon dioxide (CO2) to as much as 35 percent below 1987 levels within the next 25 years by adopting an aggressive package of policies crossing all sectors of the economy. Such emissions reductions will be difficult to achieve and may be costly, but no major technological breakthroughs are needed. In this paper, we identify a ``Tough'' package of energy conservation, energy supply, and forest managment practices to accomplish this level of emissions reductions. We also present a package of cost-effective, ``Moderate'' technical options, which if adopted, would hold CO2 emissions to about 15-percent increase over 1987 levels by 2015. In constrast, if the United State takes not new actions to curb energy use, CO2 emissions will likely rise 50 percent during that time. A variety of Federal policy initiatives will be required to achieve large reductions in U.S. CO2 emissions. Such policy actions will have to include both regulatory ``push'' and market ``pull'' mechanisms--including performance standards, tax incentive programs, carbon-emission or energy taxes, labeling and efficiency ratings, and research, development, and demostration activities.

  8. High-resolution mapping of motor vehicle carbon dioxide emissions

    NASA Astrophysics Data System (ADS)

    McDonald, Brian C.; McBride, Zoe C.; Martin, Elliot W.; Harley, Robert A.

    2014-05-01

    A fuel-based inventory for vehicle emissions is presented for carbon dioxide (CO2) and mapped at various spatial resolutions (10 km, 4 km, 1 km, and 500 m) using fuel sales and traffic count data. The mapping is done separately for gasoline-powered vehicles and heavy-duty diesel trucks. Emission estimates from this study are compared with the Emissions Database for Global Atmospheric Research (EDGAR) and VULCAN. All three inventories agree at the national level within 5%. EDGAR uses road density as a surrogate to apportion vehicle emissions, which leads to 20-80% overestimates of on-road CO2 emissions in the largest U.S. cities. High-resolution emission maps are presented for Los Angeles, New York City, San Francisco-San Jose, Houston, and Dallas-Fort Worth. Sharp emission gradients that exist near major highways are not apparent when emissions are mapped at 10 km resolution. High CO2 emission fluxes over highways become apparent at grid resolutions of 1 km and finer. Temporal variations in vehicle emissions are characterized using extensive day- and time-specific traffic count data and are described over diurnal, day of week, and seasonal time scales. Clear differences are observed when comparing light- and heavy-duty vehicle traffic patterns and comparing urban and rural areas. Decadal emission trends were analyzed from 2000 to 2007 when traffic volumes were increasing and a more recent period (2007-2010) when traffic volumes declined due to recession. We found large nonuniform changes in on-road CO2 emissions over a period of ~5 years, highlighting the importance of timely updates to motor vehicle emission inventories.

  9. Using infrastructure optimization to reduce greenhouse gas emissions from oil sands extraction and processing.

    PubMed

    Middleton, Richard S; Brandt, Adam R

    2013-02-01

    The Alberta oil sands are a significant source of oil production and greenhouse gas emissions, and their importance will grow as the region is poised for decades of growth. We present an integrated framework that simultaneously considers economic and engineering decisions for the capture, transport, and storage of oil sands CO(2) emissions. The model optimizes CO(2) management infrastructure at a variety of carbon prices for the oil sands industry. Our study reveals several key findings. We find that the oil sands industry lends itself well to development of CO(2) trunk lines due to geographic coincidence of sources and sinks. This reduces the relative importance of transport costs compared to nonintegrated transport systems. Also, the amount of managed oil sands CO(2) emissions, and therefore the CCS infrastructure, is very sensitive to the carbon price; significant capture and storage occurs only above 110$/tonne CO(2) in our simulations. Deployment of infrastructure is also sensitive to CO(2) capture decisions and technology, particularly the fraction of capturable CO(2) from oil sands upgrading and steam generation facilities. The framework will help stakeholders and policy makers understand how CCS infrastructure, including an extensive pipeline system, can be safely and cost-effectively deployed. PMID:23276202

  10. Changes in the use and management of forests for abating carbon emissions: issues and challenges under the Kyoto Protocol.

    PubMed

    Brown, Sandra; Swingland, Ian R; Hanbury-Tenison, Robin; Prance, Ghillean T; Myers, Norman

    2002-08-15

    The global carbon cycle is significantly influenced by changes in the use and management of forests and agriculture. Humans have the potential through changes in land use and management to alter the magnitude of forest-carbon stocks and the direction of forest-carbon fluxes. However, controversy over the use of biological means to absorb or reduce emissions of CO(2) (often referred to as carbon 'sinks') has arisen in the context of the Kyoto Protocol. The controversy is based primarily on two arguments: sinks may allow developed nations to delay or avoid actions to reduce fossil fuel emissions, and the technical and operational difficulties are too threatening to the successful implementation of land use and forestry projects for providing carbon offsets. Here we discuss the importance of including carbon sinks in efforts to address global warming and the consequent additional social, environmental and economic benefits to host countries. Activities in tropical forest lands provide the lowest cost methods both of reducing emissions and reducing atmospheric concentrations of greenhouse gases. We conclude that the various objections raised as to the inclusion of carbon sinks to ameliorate climate change can be addressed by existing techniques and technology. Carbon sinks provide a practical available method of achieving meaningful reductions in atmospheric concentrations of carbon dioxide while at the same time contribute to national sustainable development goals. PMID:12460486

  11. Monthly, global emissions of carbon dioxide from fossil fuel consumption

    SciTech Connect

    Andres, Robert Joseph; Gregg, JS; Losey, London M; Marland, Gregg; Boden, Thomas A

    2011-01-01

    This paper examines available data, develops a strategy and presents a monthly, global time series of fossil-fuel carbon dioxide emissions for the years 1950 2006. This monthly time series was constructed from detailed study of monthly data from the 21 countries that account for approximately 80% of global total emissions. These data were then used in a Monte Carlo approach to proxy for all remaining countries. The proportional-proxy methodology estimates by fuel group the fraction of annual emissions emitted in each country and month. Emissions from solid, liquid and gas fuels are explicitly modelled by the proportional-proxy method. The primary conclusion from this study is the global monthly time series is statistically significantly different from a uniform distribution throughout the year. Uncertainty analysis of the data presented show that the proportional-proxy method used faithfully reproduces monthly patterns in the data and the global monthly pattern of emissions is relatively insensitive to the exact proxy assignments used. The data and results presented here should lead to a better understanding of global and regional carbon cycles, especially when the mass data are combined with the stable carbon isotope data in atmospheric transport models.

  12. Carbon emissions from forest conversion by Kalimantan oil palm plantations

    NASA Astrophysics Data System (ADS)

    Carlson, Kimberly M.; Curran, Lisa M.; Asner, Gregory P.; Pittman, Alice Mcdonald; Trigg, Simon N.; Marion Adeney, J.

    2013-03-01

    Oil palm supplies >30% of world vegetable oil production. Plantation expansion is occurring throughout the tropics, predominantly in Indonesia, where forests with heterogeneous carbon stocks undergo high conversion rates. Quantifying oil palm's contribution to global carbon budgets therefore requires refined spatio-temporal assessments of land cover converted to plantations. Here, we report oil palm development across Kalimantan (538,346km2) from 1990 to 2010, and project expansion to 2020 within government-allocated leases. Using Landsat satellite analyses to discern multiple land covers, coupled with above- and below-ground carbon accounting, we develop the first high-resolution carbon flux estimates from Kalimantan plantations. From 1990 to 2010, 90% of lands converted to oil palm were forested (47% intact, 22% logged, 21% agroforests). By 2010, 87% of total oil palm area (31,640km2) occurred on mineral soils, and these plantations contributed 61-73% of 1990-2010 net oil palm emissions (0.020-0.024GtCyr-1). Although oil palm expanded 278% from 2000 to 2010, 79% of allocated leases remained undeveloped. By 2020, full lease development would convert 93,844km2 (~ 90% forested lands, including 41% intact forests). Oil palm would then occupy 34% of lowlands outside protected areas. Plantation expansion in Kalimantan alone is projected to contribute 18-22% (0.12-0.15GtCyr-1) of Indonesia's 2020 CO2-equivalent emissions. Allocated oil palm leases represent a critical yet undocumented source of deforestation and carbon emissions.

  13. Managing carbon emissions in China through building energy efficiency.

    PubMed

    Li, Jun; Colombier, Michel

    2009-06-01

    This paper attempts to analyse the role of building energy efficiency (BEE) in China in addressing climate change mitigation. It provides an analysis of the current situation and future prospects for the adoption of BEE technologies in Chinese cities. It outlines the economic and institutional barriers to large-scale deployment of the sustainable, low-carbon, and even carbon-free construction techniques. Based on a comprehensive overview of energy demand characteristics and development trends driven by economic and demographic growth, different policy tools for cost-effective CO(2) emission reduction in the Chinese construction sector are described. We propose a comprehensive approach combining building design and construction, and the urban planning and building material industries, in order to drastically improve BEE during this period of rapid urban development. A coherent institutional framework needs to be established to ensure the implementation of efficiency policies. Regulatory and incentive options should be integrated into the policy portfolios of BEE to minimise the efficiency gap and to realise sizeable carbon emissions cuts in the next decades. We analyse in detail several policies and instruments, and formulate relevant policy proposals fostering low-carbon construction technology in China. Specifically, Our analysis shows that improving building energy efficiency can generate considerable carbon emissions reduction credits with competitive price under the CDM framework. PMID:19344996

  14. Electron Field Emission from Thick Paste Carbon Materials

    NASA Astrophysics Data System (ADS)

    Reynolds, Gillian; Cheng, Lap-Tak; Bouchard, Robert; Amey, Daniel; Shah, Ismat

    2002-03-01

    Ion bombardment was used to produce electron emitting micro-scale features on surfaces printed with carbon thick film pastes. This technology can potentially enable the development of large area field emission displays (FEDs). Systematic investigations using microscopy and electron field emission experiments have demonstrated close link between paste formulation, ion processing parameters, and the development of surface microstructures. These investigations have also shed light on the fundamentals of microstructure formation and the field emission characteristics of the carbon based emitters. Several device concepts aimed towards achieving a low voltage switchable triode were also pursued with varying degree of success. In this work we summarize various material, process, and device issues related to this technology.

  15. Analysis of carbon dioxide emission of gas fuelled cogeneration plant

    NASA Astrophysics Data System (ADS)

    Nordin, Adzuieen; Amin, M.; Majid, A.

    2013-12-01

    Gas turbines are widely used for power generation. In cogeneration system, the gas turbine generates electricity and the exhaust heat from the gas turbine is used to generate steam or chilled water. Besides enhancing the efficiency of the system, the process assists in reducing the emission of CO2 to the environment. This study analyzes the amount of CO2 emission by Universiti Teknologi Petronas gas fuelled cogeneration system using energy balance equations. The results indicate that the cogeneration system reduces the CO2 emission to the environment by 60%. This finding could encourage the power plant owners to install heat recovery systems to their respective plants.

  16. Field Enhanced Thermionic Electron Emission from Oxide Coated Carbon Nanotubes

    NASA Astrophysics Data System (ADS)

    Day, Christopher; Jin, Feng; Liu, Yan; Little, Scott

    2006-03-01

    We have created a novel nanostructure by coating carbon nanotubes with a thin functional oxide layer. The structure was fabricated by sputter deposition of a thin film of oxide materials on aligned carbon nanotubes, which were grown on a tungsten substrate with plasma enhanced chemical vapor deposition. This structure combines the low work function of the oxide coating with a high field enhancement factor introduced by carbon nanotubes and we have demonstrated that it can be used as a highly efficient electron source. A field enhancement factor as high as 2000 was observed and thermionic electron emission current at least an order of magnitude higher than the emission from a conventional oxide cathode was obtained.

  17. Phosphorus-Assisted Biomass Thermal Conversion: Reducing Carbon Loss and Improving Biochar Stability

    PubMed Central

    Zhao, Ling; Cao, Xinde; Zheng, Wei; Kan, Yue

    2014-01-01

    There is often over 50% carbon loss during the thermal conversion of biomass into biochar, leading to it controversy for the biochar formation as a carbon sequestration strategy. Sometimes the biochar also seems not to be stable enough due to physical, chemical, and biological reactions in soils. In this study, three phosphorus-bearing materials, H3PO4, phosphate rock tailing (PRT), and triple superphosphate (TSP), were used as additives to wheat straw with a ratio of 1: 0.4–0.8 for biochar production at 500°C, aiming to alleviate carbon loss during pyrolysis and to increase biochar-C stabilization. All these additives remarkably increased the biochar yield from 31.7% (unmodified biochar) to 46.9%–56.9% (modified biochars). Carbon loss during pyrolysis was reduced from 51.7% to 35.5%–47.7%. Thermogravimetric analysis curves showed that the additives had no effect on thermal stability of biochar but did enhance its oxidative stability. Microbial mineralization was obviously reduced in the modified biochar, especially in the TSP-BC, in which the total CO2 emission during 60-d incubation was reduced by 67.8%, compared to the unmodified biochar. Enhancement of carbon retention and biochar stability was probably due to the formation of meta-phosphate or C-O-PO3, which could either form a physical layer to hinder the contact of C with O2 and bacteria, or occupy the active sites of the C band. Our results indicate that pre-treating biomass with phosphors-bearing materials is effective for reducing carbon loss during pyrolysis and for increasing biochar stabilization, which provides a novel method by which biochar can be designed to improve the carbon sequestration capacity. PMID:25531111

  18. Phosphorus-assisted biomass thermal conversion: reducing carbon loss and improving biochar stability.

    PubMed

    Zhao, Ling; Cao, Xinde; Zheng, Wei; Kan, Yue

    2014-01-01

    There is often over 50% carbon loss during the thermal conversion of biomass into biochar, leading to it controversy for the biochar formation as a carbon sequestration strategy. Sometimes the biochar also seems not to be stable enough due to physical, chemical, and biological reactions in soils. In this study, three phosphorus-bearing materials, H3PO4, phosphate rock tailing (PRT), and triple superphosphate (TSP), were used as additives to wheat straw with a ratio of 1: 0.4-0.8 for biochar production at 500°C, aiming to alleviate carbon loss during pyrolysis and to increase biochar-C stabilization. All these additives remarkably increased the biochar yield from 31.7% (unmodified biochar) to 46.9%-56.9% (modified biochars). Carbon loss during pyrolysis was reduced from 51.7% to 35.5%-47.7%. Thermogravimetric analysis curves showed that the additives had no effect on thermal stability of biochar but did enhance its oxidative stability. Microbial mineralization was obviously reduced in the modified biochar, especially in the TSP-BC, in which the total CO2 emission during 60-d incubation was reduced by 67.8%, compared to the unmodified biochar. Enhancement of carbon retention and biochar stability was probably due to the formation of meta-phosphate or C-O-PO3, which could either form a physical layer to hinder the contact of C with O2 and bacteria, or occupy the active sites of the C band. Our results indicate that pre-treating biomass with phosphors-bearing materials is effective for reducing carbon loss during pyrolysis and for increasing biochar stabilization, which provides a novel method by which biochar can be designed to improve the carbon sequestration capacity. PMID:25531111

  19. Field Emission Characteristics of Carbon Nanotubes and Their Applications in Sensors and Devices

    NASA Astrophysics Data System (ADS)

    Vaseashta, Ashok

    2003-03-01

    FIELD EMISSION CHARACTERISTICS OF CARBON NANOTUBES AND THEIR APPLICATIONS IN SENSORS AND DEVICES A. Vaseashta, C. Shaffer, M. Collins, A. Mwuara Dept of Physics, Marshall University, Huntington, WV V. Pokropivny Institute for Materials Sciences of NASU, Kiev, Ukraine. D. Dimova-Malinovska Bulgarian Academy of Sciences, Sofia, Bulgaria. The dimensionality of a system has profound influence on its physical behavior. With advances in technology over the past few decades, it has become possible to fabricate and study reduced-dimensional systems, such as carbon nanotubes (CNTs). Carbon nanotubes are especially promising candidate for cold cathode field emitter because of their electrical properties, high aspect ratio, and small radius of curvature at the tips. Electron emission from the carbon nanotubes was investigated. Based upon the field emission investigation of carbon nanotubes, several prototype devices have been suggested that operate with low swing voltages with sufficient high current densities. Characteristics that allow improved current stability and long lifetime operation for electrical and opto-electronics devices are presented. The aim of this brief overview is to illustrate the useful characteristics of carbon nanotubes and its possible application.

  20. Russian anthropogenic black carbon: Emission reconstruction and Arctic black carbon simulation

    NASA Astrophysics Data System (ADS)

    Huang, Kan; Fu, Joshua S.; Prikhodko, Vitaly Y.; Storey, John M.; Romanov, Alexander; Hodson, Elke L.; Cresko, Joe; Morozova, Irina; Ignatieva, Yulia; Cabaniss, John

    2015-11-01

    Development of reliable source emission inventories is particularly needed to advance the understanding of the origin of Arctic haze using chemical transport modeling. This study develops a regional anthropogenic black carbon (BC) emission inventory for the Russian Federation, the largest country by land area in the Arctic Council. Activity data from combination of local Russia information and international resources, emission factors based on either Russian documents or adjusted values for local conditions, and other emission source data are used to approximate the BC emissions. Emissions are gridded at a resolution of 0.1° × 0.1° and developed into a monthly temporal profile. Total anthropogenic BC emission of Russia in 2010 is estimated to be around 224 Gg. Gas flaring, a commonly ignored black carbon source, contributes a significant fraction of 36.2% to Russia's total anthropogenic BC emissions. Other sectors, i.e., residential, transportation, industry, and power plants, contribute 25.0%, 20.3%, 13.1%, and 5.4%, respectively. Three major BC hot spot regions are identified: the European part of Russia, the southern central part of Russia where human population densities are relatively high, and the Urals Federal District where Russia's major oil and gas fields are located but with sparse human population. BC simulations are conducted using the hemispheric version of Community Multi-scale Air Quality Model with emission inputs from a global emission database EDGAR (Emissions Database for Global Atmospheric Research)-HTAPv2 (Hemispheric Transport of Air Pollution) and EDGAR-HTAPv2 with its Russian part replaced by the newly developed Russian BC emissions, respectively. The simulation using the new Russian BC emission inventory could improve 30-65% of absorption aerosol optical depth measured at the AERONET sites in Russia throughout the whole year as compared to that using the default HTAPv2 emissions. At the four ground monitoring sites (Zeppelin, Barrow

  1. Russian anthropogenic black carbon: Emission reconstruction and Arctic black carbon simulation

    DOE PAGESBeta

    Huang, Kan; Fu, Joshua S.; Prikhodko, Vitaly Y.; Storey, John M.; Romanov, Alexander; Hodson, Elke L.; Cresko, Joe; Morozova, Irina; Ignatieva, Yulia; Cabaniss, John

    2015-10-02

    Development of reliable source emission inventories is needed to advance the understanding of the origin of Arctic haze using chemical transport modeling. This paper develops a regional anthropogenic black carbon (BC) emission inventory for the Russian Federation, the largest country by land area in the Arctic Council. Activity data from combination of local Russia information and international resources, emission factors based on either Russian documents or adjusted values for local conditions, and other emission source data are used to approximate the BC emissions. Emissions are gridded at a resolution of 0.1° × 0.1° and developed into a monthly temporal profile.more » Total anthropogenic BC emission of Russia in 2010 is estimated to be around 224 Gg. Gas flaring, a commonly ignored black carbon source, contributes a significant fraction of 36.2% to Russia's total anthropogenic BC emissions. Other sectors, i.e., residential, transportation, industry, and power plants, contribute 25.0%, 20.3%, 13.1%, and 5.4%, respectively. Three major BC hot spot regions are identified: the European part of Russia, the southern central part of Russia where human population densities are relatively high, and the Urals Federal District where Russia's major oil and gas fields are located but with sparse human population. BC simulations are conducted using the hemispheric version of Community Multi-scale Air Quality Model with emission inputs from a global emission database EDGAR (Emissions Database for Global Atmospheric Research)-HTAPv2 (Hemispheric Transport of Air Pollution) and EDGAR-HTAPv2 with its Russian part replaced by the newly developed Russian BC emissions, respectively. The simulation using the new Russian BC emission inventory could improve 30–65% of absorption aerosol optical depth measured at the AERONET sites in Russia throughout the whole year as compared to that using the default HTAPv2 emissions. At the four ground monitoring sites (Zeppelin, Barrow, Alert

  2. Russian anthropogenic black carbon: Emission reconstruction and Arctic black carbon simulation

    SciTech Connect

    Huang, Kan; Fu, Joshua S.; Prikhodko, Vitaly Y.; Storey, John M.; Romanov, Alexander; Hodson, Elke L.; Cresko, Joe; Ignatieva, Yulia; Cabaniss, John

    2015-10-02

    Development of reliable source emission inventories is needed to advance the understanding of the origin of Arctic haze using chemical transport modeling. This paper develops a regional anthropogenic black carbon (BC) emission inventory for the Russian Federation, the largest country by land area in the Arctic Council. Activity data from combination of local Russia information and international resources, emission factors based on either Russian documents or adjusted values for local conditions, and other emission source data are used to approximate the BC emissions. Emissions are gridded at a resolution of 0.1° × 0.1° and developed into a monthly temporal profile. Total anthropogenic BC emission of Russia in 2010 is estimated to be around 224 Gg. Gas flaring, a commonly ignored black carbon source, contributes a significant fraction of 36.2% to Russia's total anthropogenic BC emissions. Other sectors, i.e., residential, transportation, industry, and power plants, contribute 25.0%, 20.3%, 13.1%, and 5.4%, respectively. Three major BC hot spot regions are identified: the European part of Russia, the southern central part of Russia where human population densities are relatively high, and the Urals Federal District where Russia's major oil and gas fields are located but with sparse human population. BC simulations are conducted using the hemispheric version of Community Multi-scale Air Quality Model with emission inputs from a global emission database EDGAR (Emissions Database for Global Atmospheric Research)-HTAPv2 (Hemispheric Transport of Air Pollution) and EDGAR-HTAPv2 with its Russian part replaced by the newly developed Russian BC emissions, respectively. The simulation using the new Russian BC emission inventory could improve 30–65% of absorption aerosol optical depth measured at the AERONET sites in Russia throughout the whole year as compared to that using the default HTAPv2 emissions. At the four ground monitoring sites (Zeppelin, Barrow, Alert, and

  3. Effects of road decommissioning on carbon stocks, losses, and emissions in north coastal California

    USGS Publications Warehouse

    Madej, Mary A.; Seney, Joseph; van Mantgem, Philip

    2013-01-01

    During the last 3 decades, many road removal projects have been implemented on public and private lands in the United States to reduce erosion and other impacts from abandoned or unmaintained forest roads. Although effective in decreasing sediment production from roads, such activities have a carbon (C) cost as well as representing a carbon savings for an ecosystem. We assessed the carbon budget implications of 30 years of road decommissioning in Redwood National Park in north coastal California. Road restoration techniques, which evolved during the program, were associated with various carbon costs and savings. Treatment of 425 km of logging roads from 1979 to 2009 saved 72,000 megagrams (Mg) C through on-site soil erosion prevention, revegetation, and soil development on formerly compacted roads. Carbon sequestration will increase in time as forests and soils develop more fully on the restored sites. The carbon cost for this road decommissioning work, based on heavy equipment and vehicle fuel emissions, short-term soil loss, and clearing of vegetation, was 23,000 Mg C, resulting in a net carbon savings of 49,000 Mg C to date. Nevertheless, the degree to which soil loss is a carbon sink or source in steep mountainous watersheds needs to be further examined. The ratio of carbon costs to savings will differ by ecosystem and road removal methodology, but the procedure outlined here to assess carbon budgets on restoration sites should be transferable to other systems.

  4. Carbon dioxide and methane emission dynamics in central London (UK)

    NASA Astrophysics Data System (ADS)

    Helfter, Carole; Nemitz, Eiko; Barlow, Janet F.; Wood, Curtis R.

    2013-04-01

    London, with a population of 8.2 million, is the largest city in Europe. It is heavily built-up (typically 8% vegetation cover within the central boroughs) and boasts some of the busiest arteries in Europe despite efforts to reduce traffic in the city centre with the introduction of a congestion charging scheme in 2007. We report on two substantial pollution monitoring efforts in the heart of London between October 2006 and present. Fluxes of carbon dioxide (CO2) and water (H2O) were measured continuously by eddy-covariance in central London from October 2006 until May 2008 from a 190 m telecommunication tower (BT tower; 51° 31' 17.4'' N 0° 8' 20.04'' W). The eddy-covariance system consisted of a Gill R3-50 ultrasonic anemometer operated at 20 Hz and a LI-COR 6262 infrared gas analyser. Air was sampled 0.3 m below the sensor head of the ultrasonic anemometer - which was itself mounted on a 3 m mast to the top of a 15 m lattice tower situated on the roof of the tower (instrument head at 190 m above street level) - and pulled down 45 m of 12.7 mm OD Teflon tubing. In addition, meteorological variables (temperature, relative humidity, pressure, precipitation, wind speed and direction) were also measured with a multi-sensor (Weather Transmitter WXT510, Vaisala). Eddy-covariance measurements at the BT tower location were reinstated in July 2011 and include methane (CH4), CO2 and H2O concentrations measured by a Picarro fast methane analyser (G2301-f). CO2 emissions were found to be mainly controlled by fossil fuel combustion (e.g. traffic, commercial and domestic heating). Diurnal averages of CO2 fluxes were found to be highly correlated to traffic. However changes in heating-related natural gas consumption and, to a lesser extent, photosynthetic activity in two large city centre green spaces (Hyde Park and Regent's Park) explained the seasonal variability. Annual estimates of net exchange of CO2 obtained by eddy-covariance agreed well with up-scaled data from the UK

  5. Grape marc reduces methane emissions when fed to dairy cows.

    PubMed

    Moate, P J; Williams, S R O; Torok, V A; Hannah, M C; Ribaux, B E; Tavendale, M H; Eckard, R J; Jacobs, J L; Auldist, M J; Wales, W J

    2014-01-01

    Grape marc (the skins, seeds, stalk, and stems remaining after grapes have been pressed to make wine) is currently a by-product used as a feed supplement by the dairy and beef industries. Grape marc contains condensed tannins and has high concentrations of crude fat; both these substances can reduce enteric methane (CH4) production when fed to ruminants. This experiment examined the effects of dietary supplementation with either dried, pelleted grape marc or ensiled grape marc on yield and composition of milk, enteric CH4 emissions, and ruminal microbiota in dairy cows. Thirty-two Holstein dairy cows in late lactation were offered 1 of 3 diets: a control (CON) diet; a diet containing dried, pelleted grape marc (DGM); and a diet containing ensiled grape marc (EGM). The diet offered to cows in the CON group contained 14.0kg of alfalfa hay dry matter (DM)/d and 4.3kg of concentrate mix DM/d. Diets offered to cows in the DGM and EGM groups contained 9.0kg of alfalfa hay DM/d, 4.3kg of concentrate mix DM/d, and 5.0kg of dried or ensiled grape marc DM/d, respectively. These diets were offered individually to cows for 18d. Individual cow feed intake and milk yield were measured daily and milk composition measured on 4d/wk. Individual cow CH4 emissions were measured by the SF6 tracer technique on 2d at the end of the experiment. Ruminal bacterial, archaeal, fungal, and protozoan communities were quantified on the last day of the experiment. Cows offered the CON, DGM, and EGM diets, ate 95, 98, and 96%, respectively, of the DM offered. The mean milk yield of cows fed the EGM diet was 12.8kg/cow per day and was less than that of cows fed either the CON diet (14.6kg/cow per day) or the DGM diet (15.4kg/cow per day). Feeding DGM and EGM diets was associated with decreased milk fat yields, lower concentrations of saturated fatty acids, and enhanced concentrations of mono- and polyunsaturated fatty acids, in particular cis-9,trans-11 linoleic acid. The mean CH4 emissions were

  6. Associations of individual, household and environmental characteristics with carbon dioxide emissions from motorised passenger travel

    PubMed Central

    Brand, Christian; Goodman, Anna; Rutter, Harry; Song, Yena; Ogilvie, David

    2013-01-01

    Carbon dioxide (CO2) emissions from motorised travel are hypothesised to be associated with individual, household, spatial and other environmental factors. Little robust evidence exists on who contributes most (and least) to travel CO2 and, in particular, the factors influencing commuting, business, shopping and social travel CO2. This paper examines whether and how demographic, socio-economic and other personal and environmental characteristics are associated with land-based passenger transport and associated CO2 emissions. Primary data were collected from 3474 adults using a newly developed survey instrument in the iConnect study in the UK. The participants reported their past-week travel activity and vehicle characteristics from which CO2 emissions were derived using an adapted travel emissions profiling method. Multivariable linear and logistic regression analyses were used to examine what characteristics predicted higher CO2 emissions. CO2 emissions from motorised travel were distributed highly unequally, with the top fifth of participants producing more than two fifth of emissions. Car travel dominated overall CO2 emissions, making up 90% of the total. The strongest independent predictors of CO2 emissions were owning at least one car, being in full-time employment and having a home-work distance of more than 10 km. Income, education and tenure were also strong univariable predictors of CO2 emissions, but seemed to be further back on the causal pathway than having a car. Male gender, late-middle age, living in a rural area and having access to a bicycle also showed significant but weaker associations with emissions production. The findings may help inform the development of climate change mitigation policies for the transport sector. Targeting individuals and households with high car ownership, focussing on providing viable alternatives to commuting by car, and supporting planning and other policies that reduce commuting distances may provide an equitable and

  7. Optical emission spectroscopy of carbon arc for nanomaterial synthesis

    NASA Astrophysics Data System (ADS)

    Vekselman, Vladislav; Stratton, Brentley; Raitses, Yevgeny

    2015-11-01

    Arc plasma assisted synthesis of carbon nanostructures is one of the most efficient and simple production methods. In spite of a long time use of this method in materials science research and industrial applications, the role of the plasma in nucleation and growth of nanostructures is not well understood. This is due to complexity of physico-chemical processes governing the plasma nanosynthesis. The objective of this work is to characterize the atmospheric pressure arc plasma used for synthesis of various carbon nanostructures. Optical emission spectroscopy was carried out to determine the distribution of temperature and density of carbon plasma in the synthesis zone as a function of arc discharge parameters. Accurate and detailed mapping of plasma parameters elucidate the general trend governing the formation of carbon nanostructures. This work was supported by DOE contract DE-AC02-09CH11466.

  8. Thermionic Emission of Single-Wall Carbon Nanotubes Measured

    NASA Technical Reports Server (NTRS)

    Landis, Geoffrey A.; Krainsky, Isay L.; Bailey, Sheila G.; Elich, Jeffrey M.; Landi, Brian J.; Gennett, Thomas; Raffaelle, Ryne P.

    2004-01-01

    Researchers at the NASA Glenn Research Center, in collaboration with the Rochester Institute of Technology, have investigated the thermionic properties of high-purity, single-wall carbon nanotubes (SWNTs) for use as electron-emitting electrodes. Carbon nanotubes are a recently discovered material made from carbon atoms bonded into nanometer-scale hollow tubes. Such nanotubes have remarkable properties. An extremely high aspect ratio, as well as unique mechanical and electronic properties, make single-wall nanotubes ideal for use in a vast array of applications. Carbon nanotubes typically have diameters on the order of 1 to 2 nm. As a result, the ends have a small radius of curvature. It is these characteristics, therefore, that indicate they might be excellent potential candidates for both thermionic and field emission.

  9. An investigation into linearity with cumulative emissions of the climate and carbon cycle response in HadCM3LC

    NASA Astrophysics Data System (ADS)

    Liddicoat, S. K.; Booth, B. B. B.; Joshi, M. M.

    2016-06-01

    We investigate the extent to which global mean temperature, precipitation, and the carbon cycle are constrained by cumulative carbon emissions throughout four experiments with a fully coupled climate–carbon cycle model. The paired experiments adopt contrasting, idealised approaches to climate change mitigation at different action points this century, with total emissions rising to more than two trillion tonnes of carbon (TtC). For each pair, the contrasting mitigation approaches—capping emissions early versus reducing them to zero a few decades later—cause their cumulative emissions trajectories to diverge initially, then converge, cross, and diverge again. We find that global mean temperature is linear with cumulative emissions across all experiments, although differences of up to 1.5 K exist regionally when the trajectories of total carbon emitted during the course of the two scenarios coincide, for both pairs of experiments. Interestingly, although the oceanic precipitation response scales with cumulative emissions, the global precipitation response does not, due to a decrease in precipitation over land above emissions of around one TtC. Most carbon fluxes are less well constrained by cumulative emissions as they reach two trillion tonnes. The opposing mitigation approaches have different consequences for the Amazon rainforest, which affects the linearity with which the carbon cycle responds to cumulative emissions. The average Transient Climate Response to cumulative carbon Emissions (TCRE) is 1.95 K TtC‑1, at the upper end of the Intergovernmental Panel on Climate Change’s range of 0.8–2.5 K TtC‑1.

  10. Attributing land-use change carbon emissions to exported biomass

    SciTech Connect

    Saikku, Laura; Soimakallio, Sampo; Pingoud, Kim

    2012-11-15

    In this study, a simple, transparent and robust method is developed in which land-use change (LUC) emissions are retrospectively attributed to exported biomass products based on the agricultural area occupied for the production. LUC emissions account for approximately one-fifth of current greenhouse gas emissions. Increasing agricultural exports are becoming an important driver of deforestation. Brazil and Indonesia are used as case studies due to their significant deforestation in recent years. According to our study, in 2007, approximately 32% and 15% of the total agricultural land harvested and LUC emissions in Brazil and Indonesia respectively were due to exports. The most important exported single items with regard to deforestation were palm oil for Indonesia and bovine meat for Brazil. To reduce greenhouse gas (GHG) emissions effectively worldwide, leakage of emissions should be avoided. This can be done, for example, by attributing embodied LUC emissions to exported biomass products. With the approach developed in this study, controversial attribution between direct and indirect LUC and amortization of emissions over the product life cycle can be overcome, as the method operates on an average basis and annual level. The approach could be considered in the context of the UNFCCC climate policy instead of, or alongside with, other instruments aimed at reducing deforestation. However, the quality of the data should be improved and some methodological issues, such as the allocation procedure in multiproduct systems and the possible dilution effect through third parties not committed to emission reduction targets, should be considered. - Highlights: Black-Right-Pointing-Pointer CO{sub 2} emissions from land use changes are highly important. Black-Right-Pointing-Pointer Attribution of land use changes for products is difficult. Black-Right-Pointing-Pointer Simple and robust method is developed to attribute land use change emissions.

  11. Volcanic Carbon: Global Variations in Gas Emissions

    NASA Astrophysics Data System (ADS)

    Fischer, T. P.; de Moor, M. J.

    2014-12-01

    Magmas degas volatiles during ascent from the mantle and mafic melts with 7 wt% H2O attain volatile saturation at ~15km depth. Magmatic gases are dominated by H2O, CO2 and S species, independent of their tectonic setting. At rift volcanoes, C is sourced from the mantle whereas arc volcanoes sample both mantle and subducted C. Volcanic gases provide detailed information on volatile sources and degassing processes. Comparison of fumarole gases with melt inclusions and volcanic plumes shows that most fumaroles sample degassed magma. Water, CO2 and S vary significantly between tectonic settings. The Kuriles, Japan, and Kamchatka have H2O/CO2 of 40 to 800 while other arcs such as the Cascades, Central America, S. America, Java, and Aeolian have ratios of 1 to 70. Gases from rift volcanoes have H2O/CO2 between 3 and 9. Some of these variations are due to addition of meteoric and subducted water, as evidenced by O and H isotopes. Speciation of H and C in volcanic gases are typically controlled by redox buffer reactions imposed by the Fe3+-Fe2+ (i.e. QFM) rock buffer or the SO2-H2S gas buffer. In more exotic systems such as Poás, hydrothermal S phases such as liquid native S can play a role in high T gas C and H speciation. Arcs dominate the global subaerial volcanic CO2 emission budget and arc total fluxes vary significantly i.e. only about 2 t/yr/km from the Aleutians and about 65 t/yr/km from Central America. Reasons for this are poorly constrained and may include variability in subducted material or slab/mantle conditions at depth. A large uncertainty results from use of generalized arc-wide C/S ratios, used in calculating C fluxes, and the paucity of data for remote arcs. Resolving C fluxes from subducted versus mantle or crustal (assimilated) C relies on C isotope ratios, which can vary spatially and temporally as a function of source or degassing processes. Therefore, when considering the deep C cycle and Cexchange between the interior and surface of the Earth

  12. Shade trees reduce building energy use and CO2 emissions from power plants

    SciTech Connect

    Akbari, H.

    2001-11-01

    Urban shade trees offer significant benefits in reducing building air-conditioning demand and improving urban air quality by reducing smog. The savings associated with these benefits vary by climate region and can be up to $200 per tree. The cost of planting trees and maintaining them can vary from $10 to $500 per tree. Tree-planting programs can be designed to have lower costs so that they offer potential savings to communities that plant trees. Our calculations suggest that urban trees play a major role in sequestering C02 and thereby delay global warming. We estimate that a tree planted in Los Angeles avoids the combustion of 18 kg of carbon annually, even though it sequesters only 4.5-11 kg (as it would if growing in a forest). In this sense, one shade tree in Los Angeles is equivalent to three to five forest trees. In a recent analysis for Baton Rouge, Sacramento, and Salt Lake City, we estimated that planting an average of four shade trees per house (each with a top view cross section of 50 m2) would lead to an annual reduction in carbon emissions from power plants of 16,000, 41,000, and 9000 t, respectively (the per-tree reduction in carbon emissions is about 10-11 kg per year). These reductions only account for the direct reduction in the net cooling- and heating-energy use of buildings. Once the impact of the community cooling is included, these savings are increased by at least 25 percent.

  13. Shade trees reduce building energy use and CO2 emissions from power plants.

    PubMed

    Akbari, H

    2002-01-01

    Urban shade trees offer significant benefits in reducing building air-conditioning demand and improving urban air quality by reducing smog. The savings associated with these benefits vary by climate region and can be up to $200 per tree. The cost of planting trees and maintaining them can vary from $10 to $500 per tree. Tree-planting programs can be designed to have lower costs so that they offer potential savings to communities that plant trees. Our calculations suggest that urban trees play a major role in sequestering CO2 and thereby delay global warming. We estimate that a tree planted in Los Angeles avoids the combustion of 18 kg of carbon annually, even though it sequesters only 4.5-11 kg (as it would if growing in a forest). In this sense, one shade tree in Los Angeles is equivalent to three to five forest trees. In a recent analysis for Baton Rouge, Sacramento, and Salt Lake City, we estimated that planting an average of four shade trees per house (each with a top view cross section of 50 m2) would lead to an annual reduction in carbon emissions from power plants of 16,000, 41,000, and 9000 t, respectively (the per-tree reduction in carbon emissions is about 10-11 kg per year). These reductions only account for the direct reduction in the net cooling- and heating-energy use of buildings. Once the impact of the community cooling is included, these savings are increased by at least 25%. PMID:11833899

  14. Does carbonation of steel slag particles reduce their toxicity? An in vitro approach.

    PubMed

    Ibouraadaten, Saloua; van den Brule, Sybille; Lison, Dominique

    2015-06-01

    Mineral carbonation can stabilize industrial residues and, in the steel industry, may contribute to simultaneously valorize CO2 emissions and slag. We hypothesized that, by restricting the leaching of metals of toxicological concern such as Cr and V, carbonation can suppress the toxicity of these materials. The cytotoxic activity (WST1 assay) of slag dusts collected from a stainless and a Linz-Donawitz (LD) steel plant, before and after carbonation, was examined in J774 macrophages. The release of Cr, V, Fe, Mn and Ni was measured after incubation in artificial lung fluids mimicking the extracellular and phagolysosomal milieu to which particles are confronted after inhalation. LD slag had the higher Fe, Mn and V content, and was more cytotoxic than stainless steel slag. The cytotoxic activity of LD but not of stainless dusts was reduced after carbonation. The cytotoxic activity of the dusts toward J774 macrophages necessitated a direct contact with the cells and was reduced in the presence of inhibitors of phagocytosis (cytochalasin D) or phagolysosome acidification (bafilomycin), pointing to a key role of metallic constituents released in phagolysosomes. This in vitro study supports a limited reduction of the cytotoxic activity of LD, but not of stainless, steel dusts upon carbonation. PMID:25735930

  15. Carbon dioxide and methane emissions from the Yukon River system

    USGS Publications Warehouse

    Striegl, Rob; Dornblaser, Mark M.; McDonald, Cory P.; Rover, Jennifer R.; Stets, Edward G.

    2012-01-01

    Carbon dioxide (CO2) and methane (CH4) emissions are important, but poorly quantified, components of riverine carbon (C) budgets. This is largely because the data needed for gas flux calculations are sparse and are spatially and temporally variable. Additionally, the importance of C gas emissions relative to lateral C exports is not well known because gaseous and aqueous fluxes are not commonly measured on the same rivers. We couple measurements of aqueous CO2 and CH4 partial pressures (pCO2, pCH4) and flux across the water-air interface with gas transfer models to calculate subbasin distributions of gas flux density. We then combine those flux densities with remote and direct observations of stream and river water surface area and ice duration, to calculate C gas emissions from flowing waters throughout the Yukon River basin. CO2emissions were 7.68 Tg C yr−1 (95% CI: 5.84 −10.46), averaging 750 g C m−2 yr−1 normalized to water surface area, and 9.0 g C m−2 yr−1 normalized to river basin area. River CH4 emissions totaled 55 Gg C yr−1 or 0.7% of the total mass of C emitted as CO2 plus CH4 and ∼6.4% of their combined radiative forcing. When combined with lateral inorganic plus organic C exports to below head of tide, C gas emissions comprised 50% of total C exported by the Yukon River and its tributaries. River CO2 and CH4 derive from multiple sources, including groundwater, surface water runoff, carbonate equilibrium reactions, and benthic and water column microbial processing of organic C. The exact role of each of these processes is not yet quantified in the overall river C budget.

  16. Trend in global black carbon emissions from 1960 to 2007.

    PubMed

    Wang, Rong; Tao, Shu; Shen, Huizhong; Huang, Ye; Chen, Han; Balkanski, Yves; Boucher, Olivier; Ciais, Philippe; Shen, Guofeng; Li, Wei; Zhang, Yanyan; Chen, Yuanchen; Lin, Nan; Su, Shu; Li, Bengang; Liu, Junfeng; Liu, Wenxin

    2014-06-17

    Black carbon (BC) plays an important role in both climate change and health impact. Still, BC emissions as well as the historical trends are associated with high uncertainties in existing inventories. In the present study, global BC emissions from 1960 to 2007 were estimated for 64 sources, by using recompiled fuel consumption and emission factor data sets. Annual BC emissions had increased from 5.3 (3.4-8.5 as an interquartile range) to 9.1 (5.6-14.4) teragrams during this period. Our estimations are 11-16% higher than those in previous inventories. Over the period, we found that the BC emission intensity, defined as the amount of BC emitted per unit of energy production, had decreased for all the regions, especially China and India. Improvements in combustion technology and changes in fuel composition had led to an increase in energy use efficiency, and subsequently a decline of BC emission intensities in power plants, the residential sector, and transportation. On the other hand, the BC emission intensities had increased in the industrial and agricultural sectors, mainly due to an expansion of low-efficiency industry (coke and brick production) in developing countries and to an increasing usage of diesel in agriculture in developed countries. PMID:24825392

  17. Energy, Carbon-emission and Financial Savings from Thermostat Control

    SciTech Connect

    Blasing, T J; Schroeder, Dana

    2013-08-01

    Among the easiest approaches to energy, and cost, savings for most people is the adjustment of thermostats to save energy. Here we estimate savings of energy, carbon, and money in the United States of America (USA) that would result from adjusting thermostats in residential and commercial buildings by about half a degree Celsius downward during the heating season and upward during the cooling season. To obtain as small a unit as possible, and therefore the least likely to be noticeable by most people, we selected an adjustment of one degree Fahrenheit (0.56 degree Celsius) which is the gradation used almost exclusively on thermostats in the USA and is the smallest unit of temperature that has been used historically. Heating and/or cooling of interior building space for personal comfort is sometimes referred to as space conditioning, a term we will use for convenience throughout this work without consideration of humidity. Thermostat adjustment, as we use the term here, applies to thermostats that control the indoor temperature, and not to other thermostats such as those on water heaters. We track emissions of carbon only, rather than of carbon dioxide, because carbon atoms change atomic partners as they move through the carbon cycle, from atmosphere to biosphere or ocean and, on longer time scales, through the rock cycle. To convert a mass of carbon to an equivalent mass of carbon dioxide (thereby including the mass of the 2 oxygen atoms in each molecule) simply multiply by 3.67.

  18. Global carbon dioxide emission to the atmosphere by volcanoes

    SciTech Connect

    Williams, S.N.; Schaefer, S.J. ); Calvache V., M.L. Observatorio Vulcanologico de Colombia, Pasto ); Lopez, D. )

    1992-04-01

    Global emission of carbon dioxide by subaerial volcanoes is calculated, using CO{sub 2}/SO{sub 2} from volcanic gas analyses and SO{sub 2} flux, to be 34 {plus minus} 24 {times} 10{sup 12} g CO{sub 2}/yr from passive degassing and 31 {plus minus} 22 {times} 10{sup 12} g CO{sub 2}/yr from eruptions. Volcanic CO{sub 2} presently represents only 0.22% of anthropogenic emissions but may have contributed to significant greenhouse' effects at times in Earth history. Models of climate response to CO{sub 2} increases may be tested against geological data.

  19. 76 FR 80368 - Notification of Teleconferences of the Science Advisory Board Biogenic Carbon Emissions Panel

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-23

    ... draft report and accounting framework. As noticed in 76 FR 61100-61101, the SAB Biogenic Carbon... AGENCY Notification of Teleconferences of the Science Advisory Board Biogenic Carbon Emissions Panel... Biogenic Carbon Emissions Panel to review EPA's draft Accounting Framework for Biogenic CO2 Emissions...

  20. Reducing biomass recalcitrance via mild sodium carbonate pretreatment.

    PubMed

    Mirmohamadsadeghi, Safoora; Chen, Zhu; Wan, Caixia

    2016-06-01

    This study examined the effects of mild sodium carbonate (Na2CO3) pretreatment on enzymatic hydrolysis of different feedstocks (i.e., corn stover, Miscanthus, and switchgrass). The results showed that sodium carbonate pretreatment markedly enhanced the sugar yields of the tested biomass feedstocks. The pretreated corn stover, Miscanthus, and switchgrass gave the glucose yields of 95.1%, 62.3%, and 81.3%, respectively, after enzymatic hydrolysis. The above glucose yields of pretreated feedstocks were 2-4 times that of untreated ones. The pretreatment also enhanced the xylose yields, 4 times for corn stover and 20 times for both Miscanthus and switchgrass. Sodium carbonate pretreatment removed 40-59% lignin from the tested feedstocks while preserving most of cellulose (<5% cellulose loss). Corn stover appeared to be least resistant to breakdown by Na2CO3 and enzymatic hydrolysis. Our study indicated that mild sodium carbonate pretreatment was effective for reducing biomass recalcitrance and subsequently improving the digestibility of lignocellulosic biomass. PMID:26972025

  1. Reducing U.S. residential energy use and CO2 emissions: how much, how soon, and at what cost?

    PubMed

    Lima Azevedo, Inês; Morgan, M Granger; Palmer, Karen; Lave, Lester B

    2013-03-19

    There is growing interest in reducing energy use and emissions of carbon dioxide from the residential sector by deploying cost-effectiveness energy efficiency measures. However, there is still large uncertainty about the magnitude of the reductions that could be achieved by pursuing different energy efficiency measures across the nation. Using detailed estimates of the current inventory and performance of major appliances in U.S. homes, we model the cost, energy, and CO2 emissions reduction if they were replaced with alternatives that consume less energy or emit less CO2. We explore trade-offs between reducing CO2, reducing primary or final energy, or electricity consumption. We explore switching between electricity and direct fuel use, and among fuels. The trade-offs between different energy efficiency policy goals, as well as the environmental metrics used, are important but have been largely unexplored by previous energy modelers and policy-makers. We find that overnight replacement of the full stock of major residential appliances sets an upper bound of just over 710 × 10(6) tonnes/year of CO2 or a 56% reduction from baseline residential emissions. However, a policy designed instead to minimize primary energy consumption instead of CO2 emissions will achieve a 48% reduction in annual carbon dioxide emissions from the nine largest energy consuming residential end-uses. Thus, we explore the uncertainty regarding the main assumptions and different policy goals in a detailed sensitivity analysis. PMID:23398047

  2. Forest and grassland cover types reduce net greenhouse gas emissions from agricultural soils.

    PubMed

    Baah-Acheamfour, Mark; Carlyle, Cameron N; Lim, Sang-Sun; Bork, Edward W; Chang, Scott X

    2016-11-15

    Western Canada's prairie region is extensively cultivated for agricultural production, which is a large source of greenhouse gas emissions. Agroforestry systems are common land uses across Canada, which integrate trees into the agricultural landscape and could play a substantial role in sequestering carbon and mitigating increases in atmospheric GHG concentrations. We measured soil CO2, CH4 and N2O fluxes and the global warming potential of microbe-mediated net greenhouse gas emissions (GWPm) in forest and herbland (areas without trees) soils of three agroforestry systems (hedgerow, shelterbelt and silvopasture) over two growing seasons (May through September in 2013 and 2014). We measured greenhouse gas fluxes and environmental conditions at 36 agroforestry sites (12 sites for each system) located along a south-north oriented soil/climate gradient of increasing moisture availability in central Alberta, Canada. The temperature sensitivity of soil CO2 emissions was greater in herbland (4.4) than in forest (3.1), but was not different among agroforestry systems. Over the two seasons, forest soils had 3.4% greater CO2 emission, 36% higher CH4 uptake, and 66% lower N2O emission than adjacent herbland soils. Combining the CO2 equivalents of soil CH4 and N2O fluxes with the CO2 emitted via heterotrophic (microbial) respiration, forest soils had a smaller GWPm than herbland soils (68 and 89kgCO2ha(-1), respectively). While emissions of total CO2 were silvopasture>hedgerow>shelterbelt, soils under silvopasture had 5% lower heterotrophic respiration, 15% greater CH4 uptake, and 44% lower N2O emission as compared with the other two agroforestry systems. Overall, the GWPm of greenhouse gas emissions was greater in hedgerow (88) and shelterbelt (85) than in the silvopasture system (76kgCO2ha(-1)). High GWPm in the hedgerow and shelterbelt systems reflects the greater contribution from the monoculture annual crops within these systems. Opportunities exist for reducing soil

  3. Correlating benzene, total hydrocarbon and carbon monoxide emissions from wood-fired boilers

    SciTech Connect

    Hubbard, A.J.; Grande, D.E.; Berens, J.R.; Piotrowski, J.

    1997-12-31

    Hazardous air pollutants, including benzene, are generated by the incomplete combustion of fuels. Organic compound emissions, which are generally products of incomplete combustion, are reduced by promoting high quality combustion, for example by controlling furnace exit temperatures and establishing minimum residence times. Monitoring carbon monoxide (CO) emissions is important since the amount of carbon monoxide emitted represents the quality of combustion which in turn represents the amount of hazardous air pollutants being generated. Total hydrocarbon (THC) emissions are also related to the quality of combustion. Recently the Wisconsin Department of Natural Resources (DNR) measured the benzene and total hydrocarbon emissions from two large industrial wood fired boilers. These boilers are located at Tenneco Packaging, a container board manufacturing facility in northern Wisconsin. Temperature, oxygen and carbon monoxide concentrations were sampled continuously by Tenneco Packaging`s emission monitoring system. The Department`s team used an organic vapor analyzer to continuously measure concentrations of total hydrocarbons (THC). The Department`s team also used a modified USEPA Method 18 sampling train to capture organic vapors for subsequent analysis by gas chromatography. The data show correlations between benzene and carbon monoxide, and between benzene and THC concentrations. The emissions sampling occurred both upstream of the particulate emissions control system as well as at the stack. The CO variations during actual boiler operation appeared to be well correlated with changes in boiler steam load. That is, increases in CO generally accompanied a change, either up or down, in boiler load. Lower concentrations of CO were associated with stable combustion, as indicated by periods of constant or nearly constant boiler load.

  4. Carbon emissions performance of commercial logging in East Kalimantan, Indonesia.

    PubMed

    Griscom, Bronson; Ellis, Peter; Putz, Francis E

    2014-03-01

    Adoption of reduced-impact logging (RIL) methods could reduce CO2 emissions by 30-50% across at least 20% of remaining tropical forests. We developed two cost effective and robust indices for comparing the climate benefits (reduced CO2 emissions) due to RIL. The indices correct for variability in the volume of commercial timber among concessions. We determined that a correction for variability in terrain slope was not needed. We found that concessions certified by the Forest Stewardship Council (FSC, N = 3), when compared with noncertified concessions (N = 6), did not have lower overall CO2 emissions from logging activity (felling, skidding, and hauling). On the other hand, FSC certified concessions did have lower emissions from one type of logging impact (skidding), and we found evidence of a range of improved practices using other field metrics. One explanation of these results may be that FSC criteria and indicators, and associated RIL practices, were not designed to achieve overall emissions reductions. Also, commonly used field metrics are not reliable proxies for overall logging emissions performance. Furthermore, the simple distinction between certified and noncertified concessions does not fully represent the complex history of investments in improved logging practices. To clarify the relationship between RIL and emissions reductions, we propose the more explicit term 'RIL-C' to refer to the subset of RIL practices that can be defined by quantified thresholds and that result in measurable emissions reductions. If tropical forest certification is to be linked with CO2 emissions reductions, certification standards need to explicitly require RIL-C practices. PMID:24022913

  5. Management Options for Reducing Ammonia Emissions from Poultry Litter

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ammonia emissions from poultry litter not only result in air pollution; high levels of ammonia in poultry houses cause poor bird performance, increase the susceptibility of birds to viral diseases, and negatively impact human health. Although ammonia emissions are a concern, few cost-effective best ...

  6. Reducing Open Cell Landfill Methane Emissions with a Bioactive Alternative Daily

    SciTech Connect

    Helene Hilger; James Oliver; Jean Bogner; David Jones

    2009-03-31

    Methane and carbon dioxide are formed in landfills as wastes degrade. Molecule-for-molecule, methane is about 20 times more potent than carbon dioxide at trapping heat in the earth's atmosphere, and thus, it is the methane emissions from landfills that are scrutinized. For example, if emissions composed of 60% methane and 40% carbon dioxide were changed to a mix that was 40% methane and 60% carbon dioxide, a 30% reduction in the landfill's global warming potential would result. A 10% methane, 90% carbon dioxide ratio will result in a 75% reduction in global warming potential compared to the baseline. Gas collection from a closed landfill can reduce emissions, and it is sometimes combined with a biocover, an engineered system where methane oxidizing bacteria living in a medium such as compost, convert landfill methane to carbon dioxide and water. Although methane oxidizing bacteria merely convert one greenhouse gas (methane) to another (carbon dioxide), this conversion can offer significant reductions in the overall greenhouse gas contribution, or global warming potential, associated with the landfill. What has not been addressed to date is the fact that methane can also escape from a landfill when the active cell is being filled with waste. Federal regulations require that newly deposited solid waste to be covered daily with a 6 in layer of soil or an alternative daily cover (ADC), such as a canvas tarp. The aim of this study was to assess the feasibility of immobilizing methane oxidizing bacteria into a tarp-like matrix that could be used for alternative daily cover at open landfill cells to prevent methane emissions. A unique method of isolating methanotrophs from landfill cover soil was used to create a liquid culture of mixed methanotrophs. A variety of prospective immobilization techniques were used to affix the bacteria in a tarp-like matrix. Both gel encapsulation of methanotrophs and gels with liquid cores containing methanotrophs were readily made but

  7. The IR emission features - Emission from PAH molecules and amorphous carbon particles

    NASA Technical Reports Server (NTRS)

    Allamandola, L. J.; Tielens, A. G. G. M.; Barker, J. R.

    1987-01-01

    Techniques for the assessment of the importance of the various forms of PAHs, and recent infrared observations concerning the PAH problem, are considered. Spectroscopic data suggest that the observed interstellar spectrum is due to both free molecule-sized PAHs producing the narrow features, and amorphous carbon particles contributing to the broad underlying components. Explanations for the multicomponent emission spectrum are discussed. A model of the emission mechanism for the example of chrysene is presented, and an exact treatment of the IR fluorescence from highly vibrationally excited large molecules shows that species containing 20-30 carbon atoms are responsible for the narrow features, although the spectra more closely resemble those of amorphous carbon particles. It is suggested that future emphasis should be placed on the spatial characteristics of the component spectra.

  8. Stable carbon isotope fractionation by sulfate-reducing bacteria

    NASA Technical Reports Server (NTRS)

    Londry, Kathleen L.; Des Marais, David J.

    2003-01-01

    Biogeochemical transformations occurring in the anoxic zones of stratified sedimentary microbial communities can profoundly influence the isotopic and organic signatures preserved in the fossil record. Accordingly, we have determined carbon isotope discrimination that is associated with both heterotrophic and lithotrophic growth of pure cultures of sulfate-reducing bacteria (SRB). For heterotrophic-growth experiments, substrate consumption was monitored to completion. Sealed vessels containing SRB cultures were harvested at different time intervals, and delta(13)C values were determined for gaseous CO(2), organic substrates, and products such as biomass. For three of the four SRB, carbon isotope effects between the substrates, acetate or lactate and CO(2), and the cell biomass were small, ranging from 0 to 2 per thousand. However, for Desulfotomaculum acetoxidans, the carbon incorporated into biomass was isotopically heavier than the available substrates by 8 to 9 per thousand. SRB grown lithoautotrophically consumed less than 3% of the available CO(2) and exhibited substantial discrimination (calculated as isotope fractionation factors [alpha]), as follows: for Desulfobacterium autotrophicum, alpha values ranged from 1.0100 to 1.0123; for Desulfobacter hydrogenophilus, the alpha value was 0.0138, and for Desulfotomaculum acetoxidans, the alpha value was 1.0310. Mixotrophic growth of Desulfovibrio desulfuricans on acetate and CO(2) resulted in biomass with a delta(13)C composition intermediate to that of the substrates. The extent of fractionation depended on which enzymatic pathways were used, the direction in which the pathways operated, and the growth rate, but fractionation was not dependent on the growth phase. To the extent that environmental conditions affect the availability of organic substrates (e.g., acetate) and reducing power (e.g., H(2)), ecological forces can also influence carbon isotope discrimination by SRB.

  9. 2002 Monthly Carbon Dioxide Emissions from Mexico at a 10x10k Spatial Resolution

    NASA Astrophysics Data System (ADS)

    Mendoza, D. L.; Gurney, K. R.; Geethakumar, S.; Zhou, Y.; Sahni, N.

    2009-12-01

    The contribution of fossil fuel CO2 emissions to the total measured amount of CO2 in the Earth’s atmosphere remains an important component of carbon cycle science, particularly as efforts to understand the net exchange of carbon at the surface move to smaller scales. In order to reduce the uncertainty of this flux, researchers led by Purdue University have built a high-resolution fossil fuel CO2 flux inventory for the United States, called “Vulcan”. The Vulcan inventory quantifies emissions for the United States at 10km resolution every hour for the year 2002 and can be seen as a key component of a national assessment and verification system for greenhouse gas emissions and emissions mitigation. As part of the North American Carbon Project, the 2002 carbon dioxide emissions from Mexico are presented at the monthly temporal and municipality spatial scale. Mexico is of particular importance because of the scientific integration under the North American Carbon Program. Furthermore, Mexico has seen a notable growth in its population as well as migration toward urban centers and increasing energy requirements due in part to industrial intensification. The native resolution of the emissions is geolocated (lat/lon) for point sources, such as power plants, airports, and large industry. The emissions are estimated at the municipality level for residential and commercial sources, and allocated to roads for the mobile transport sector. Data sources include the National Emissions Inventory (NEI), Commission for Environmental Cooperation (CEC), and Carbon Monitoring for Action (CARMA). CO2 emissions are calculated from the 1999 NEI data by converting CO emissions using sector and process-dependent emission factors, and is scaled up to 2002 using statistics obtained from the Carbon Dioxide Information Analysis Center CDIAC. CEC and CARMA data, which encompass power plant emissions, are already in units of CO2. Emissions are regridded to 10x10k and 0.1x0.1 deg grids to

  10. Energy Use and Carbon Emissions: Some International Comparisons

    EIA Publications

    1994-01-01

    Presents energy use and carbon emissions patterns in a world context. The report contrasts trends in economically developed and developing areas of the world since 1970, presents a disaggregated view of the "Group of Seven" (G7) key industrialized countries (Canada, France, Germany, Italy, Japan, the United Kingdom, and the United States) and examines sectoral energy use patterns within each of the G7 countries.

  11. Densification effects of the carbon nanotube pillar array on field-emission properties

    NASA Astrophysics Data System (ADS)

    Wang, Kuang-Yu; Chou, Chia-Hsin; Liao, Chan-Yu; Li, Yu-Ren; Cheng, Huang-Chung

    2016-06-01

    In this study, a simple densification method for carbon nanotube (CNT) pillars is proposed to achieve high-performance field emission characteristics and stable emission. Through capillary force during solution evaporation, the CNT density in each pillar can be increased by about six times without causing damage to the crystallinity of CNTs. The densified CNT pillars exhibit lower series resistance, sharper pillars, better contacts, higher thermal conductivity, and better mechanical stiffness than as-grown ones. Therefore, the threshold field of the field emitter with such CNT pillars of 50 µm height can be reduced to 1.98 V/µm, as compared with 2.2 V/µm for the undensified ones. Moreover, the fluctuation of field-emission current decreases from 15.5 to 9.4% after the stress tests at a field of 2 V/µm for 1800 s. These findings imply that the densified CNT pillars are promising for the field-emission applications.

  12. Experimental and theoretical study on field emission properties of zinc oxide nanoparticles decorated carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Li, Xin; Zhou, Wei-Man; Liu, Wei-Hua; Wang, Xiao-Li

    2015-05-01

    Field emission properties of zinc oxide (ZnO) nanoparticles (NPs) decorated carbon nanotubes (CNTs) are investigated experimentally and theoretically. CNTs are in situ decorated with ZnO NPs during the growth process by chemical vapor deposition using a carbon source from the iron phthalocyanine pyrolysis. The experimental field emission test shows that the ZnO NP decoration significantly improves the emission current from 50 μA to 275 μA at 550 V and the reduced threshold voltage from 450 V to 350 V. The field emission mechanism of ZnO NPs on CNTs is theoretically studied by the density functional theory (DFT) combined with the Penn-Plummer method. The ZnO NPs reconstruct the ZnO-CNT structure and pull down the surface barrier of the entire emitter system to 0.49 eV so as to reduce the threshold electric field. The simulation results suggest that the presence of ZnO NPs would increase the LDOS near the Fermi level and increase the emission current. The calculation results are consistent with the experiment results. Project supported by the National Natural Science Foundation of China (Grant Nos. 91123018, 61172040, and 61172041) and the Natural Science Foundation of Shaanxi Province, China (Grant No. 2014JM7277).

  13. Just Say No to Carbon Emissions (LBNL Science at the Theater)

    ScienceCinema

    Ramesh, Ramamoorthy; Zhou, Nan; Oldenburg, Curt

    2011-04-28

    Learn about three efforts our grandchildren may thank us for: cheap solar energy, bringing energy efficiency to China, and learning how to store carbon deep underground. Can solar energy be dirt cheap? We're all potentially billionaires when it comes to solar energy. The trick is learning how to convert sunlight to electricity using cheap and plentiful materials. Ramamoorthy Ramesh, an innovative materials scientist at Berkeley Lab, will discuss how he and other researchers are working to make photovoltaic cells using the most abundant elements in the Earth's crust -- materials that are literally as common as dirt. Energy efficiency in China: Nan Zhou is a researcher with Berkeley Labs China Energy Group. She will speak about Chinas energy use and the policies that have been implemented to increase energy efficiency and reduce CO2 emission growth. Her work focuses on building China's capacity to evaluate, adopt and implement low-carbon development strategies. Zhou has an architecture degree from China, and a Master and Ph.D. in Engineering from Japan. Understanding geologic carbon sequestration: Even with continued growth of renewable energy sources such as wind and solar, fossil fuels will likely remain cheap and plentiful for decades to come. Geologist Curt Oldenburg, who heads Berkeley Lab's Geologic Carbon Sequestration Program, will discuss a strategy to reduce carbon emissions from coal and natural gas. It involves pumping compressed CO2 captured from large stationary sources into underground rock formations that can store it for geological time scales.

  14. Just Say No to Carbon Emissions (LBNL Science at the Theater)

    SciTech Connect

    Ramesh, Ramamoorthy; Zhou, Nan; Oldenburg, Curt

    2010-04-26

    Learn about three efforts our grandchildren may thank us for: cheap solar energy, bringing energy efficiency to China, and learning how to store carbon deep underground. Can solar energy be dirt cheap? We're all potentially billionaires when it comes to solar energy. The trick is learning how to convert sunlight to electricity using cheap and plentiful materials. Ramamoorthy Ramesh, an innovative materials scientist at Berkeley Lab, will discuss how he and other researchers are working to make photovoltaic cells using the most abundant elements in the Earth's crust -- materials that are literally as common as dirt. Energy efficiency in China: Nan Zhou is a researcher with Berkeley Labs China Energy Group. She will speak about Chinas energy use and the policies that have been implemented to increase energy efficiency and reduce CO2 emission growth. Her work focuses on building China's capacity to evaluate, adopt and implement low-carbon development strategies. Zhou has an architecture degree from China, and a Master and Ph.D. in Engineering from Japan. Understanding geologic carbon sequestration: Even with continued growth of renewable energy sources such as wind and solar, fossil fuels will likely remain cheap and plentiful for decades to come. Geologist Curt Oldenburg, who heads Berkeley Lab's Geologic Carbon Sequestration Program, will discuss a strategy to reduce carbon emissions from coal and natural gas. It involves pumping compressed CO2 captured from large stationary sources into underground rock formations that can store it for geological time scales.

  15. Global Civil Aviation Black Carbon Particle Mass and Number Emissions

    NASA Astrophysics Data System (ADS)

    Stettler, M. E. J.

    2015-12-01

    Black carbon (BC) is a product of incomplete combustion emitted by aircraft engines. In the atmosphere, BC particles strongly absorb incoming solar radiation and influence cloud formation processes leading to highly uncertain, but likely net positive warming of the earth's atmosphere. At cruise altitude, BC particle number emissions can influence the concentration of ice nuclei that can lead to contrail formation, with significant and highly uncertainty climate impacts. BC particles emitted by aircraft engines also degrade air quality in the vicinity of airports and globally. A significant contribution to the uncertainty in environmental impacts of aviation BC emissions is the uncertainty in emissions inventories. Previous work has shown that global aviation BC mass emissions are likely to have been underestimated by a factor of three. In this study, we present an updated global BC particle number inventory and evaluate parameters that contribute to uncertainty using global sensitivity analysis techniques. The method of calculating particle number from mass utilises a description of the mobility of fractal aggregates and uses the geometric mean diameter, geometric standard deviation, mass-mobility exponent, primary particle diameter and material density to relate the particle number concentration to the total mass concentration. Model results show good agreement with existing measurements of aircraft BC emissions at ground level and at cruise altitude. It is hoped that the results of this study can be applied to estimate direct and indirect climate impacts of aviation BC emissions in future studies.

  16. Chemical and stable carbon isotopic composition of PM2.5 from on-road vehicle emissions in the PRD region and implication for vehicle emission control policy

    NASA Astrophysics Data System (ADS)

    Dai, S.; Bi, X.; Chan, L. Y.; He, J.; Wang, B.; Wang, X.; Sheng, G.; Fu, J.

    2014-11-01

    Vehicle emission is a major source of urban air pollution. In recent decade, the Chinese government has introduced a range of policies to reduce the vehicle emission. In order to understand the chemical characteristics of PM2.5 from on-road vehicle emission in the Pearl River Delta (PRD) region and to evaluate the effectiveness of control policies on vehicles emission, the emission factors of PM2.5 mass, elemental carbon (EC), organic carbon (OC), water-soluble organic carbon (WSOC), water-soluble inorganic ions (WSII), metal elements, organic compounds and stable carbon isotopic composition were measured in the Zhujiang Tunnel of Guangzhou, the PRD region of China in 2013. Emission factors of PM2.5 mass, OC, EC, and WSOC were 92.4, 16.7, 16.4, and 1.31 mg vehicle-1 km-1 respectively. Emission factors of WSII were 0.016 (F-) ~4.17 (Cl-) mg vehicle-1 km-1, totally contributing about 9.8% to the PM2.5 emissions. The sum of 27 measured metal elements accounted for 15.2% of the PM2.5 emissions. Fe was the most abundant metal element, with an emission factor of 3.91 mg vehicle-1 km-1. Emission factors of organic compounds including n-alkanes, PAHs, hopanes, and steranes were 91.9, 5.02, 32.0 and 7.59 μg vehicle-1 km-1, respectively. Stable carbon isotopic composition δ13C value was measured and it was -25.0‰ on average. An isotopic fractionation of 3.2‰ was found during fuel combustion. Compared with a previous study in Zhujiang Tunnel in year 2004, emission factors of PM2.5 mass, EC, OC, WSII except Cl-, and organic compounds decreased by 16.0-93.4%, which could be attributed to emission control policy from 2004 to 2013. However, emission factors of most of the metal elements increased significantly, which could be partially attributed to the changes in motor oil additives and vehicle condition. There are no mandatory national standards to limit metal content from vehicle emission, which should be a concern of the government. A snapshot of the 2013 characteristic

  17. Chemical and stable carbon isotopic composition of PM2.5 from on-road vehicle emissions in the PRD region and implications for vehicle emission control policy

    NASA Astrophysics Data System (ADS)

    Dai, S.; Bi, X.; Chan, L. Y.; He, J.; Wang, B.; Wang, X.; Peng, P.; Sheng, G.; Fu, J.

    2015-03-01

    Vehicle emissions are a major source of urban air pollution. In recent decade, the Chinese government has introduced a range of policies to reduce vehicle emissions. In order to understand the chemical characteristics of PM2.5 from on-road vehicle emissions in the Pearl River Delta (PRD) region and to evaluate the effectiveness of control policies on vehicle emissions, the emission factors of PM2.5 mass, elemental carbon (EC), organic carbon (OC), water-soluble organic carbon (WSOC), water-soluble inorganic ions (WSII), metal elements, organic compounds and stable carbon isotopic composition were measured in the Zhujiang tunnel of Guangzhou, in the PRD region of China in 2013. Emission factors of PM2.5 mass, OC, EC and WSOC were 92.4, 16.7, 16.4 and 1.31 mg vehicle-1 km-1 respectively. Emission factors of WSII were 0.016 (F-) ~ 4.17 (Cl-) mg vehicle-1 km-1, contributing about 9.8% to the PM2.5 emissions. The sum of 27 measured metal elements accounted for 15.2% of PM2.5 emissions. Fe was the most abundant metal element, with an emission factor of 3.91 mg vehicle-1 km-1. Emission factors of organic compounds including n-alkanes, polycyclic aromatic hydrocarbons, hopanes and steranes were 91.9, 5.02, 32.0 and 7.59 μg vehicle-1 km-1, respectively. Stable carbon isotopic composition δ13C value was -25.0‰ on average. An isotopic fractionation of 3.2‰ was found during fuel combustion. Compared to a previous study in Zhujiang tunnel in 2004, emission factors of PM2.5mass, EC, OC, WSII except Cl- and organic compounds decreased by 16.0 ~ 93.4%, which could be attributed to emission control policy from 2004 to 2013. However, emission factors of most of the metal elements increased significantly, which could be partially attributed to the changes in motor oil additives and vehicle conditions. There are no mandatory national standards to limit metal content from vehicle emissions, which should be a concern of the government. A snapshot of the 2013 characteristic

  18. Hydrogen sensing characteristics from carbon nanotube field emissions.

    PubMed

    Dong, Changkun; Luo, Haijun; Cai, Jianqiu; Wang, Fuquan; Zhao, Yangyang; Li, Detian

    2016-03-14

    An innovative hydrogen sensing concept is demonstrated based on the field emission from multi-walled carbon nanotubes, where the low emission currents rise in proportion to hydrogen partial pressures above 10(-9) Torr. Experimental and first principles studies reveal that the sensing mechanism is attributed to the effective work function reduction from dissociative hydrogen chemisorption. The embedded Ni catalyst would assist both the hydrogen dissociation and work function reduction. This technique is promising to build miniature low cost hydrogen sensors for multiple applications. This work is valuable for studies of nanocarbon-gas reaction mechanisms and the work function properties in adsorption related applications, including field emission, hydrogen storage, energy cells, and gas sensing. PMID:26890686

  19. Hydrogen sensing characteristics from carbon nanotube field emissions

    NASA Astrophysics Data System (ADS)

    Dong, Changkun; Luo, Haijun; Cai, Jianqiu; Wang, Fuquan; Zhao, Yangyang; Li, Detian

    2016-03-01

    An innovative hydrogen sensing concept is demonstrated based on the field emission from multi-walled carbon nanotubes, where the low emission currents rise in proportion to hydrogen partial pressures above 10-9 Torr. Experimental and first principles studies reveal that the sensing mechanism is attributed to the effective work function reduction from dissociative hydrogen chemisorption. The embedded Ni catalyst would assist both the hydrogen dissociation and work function reduction. This technique is promising to build miniature low cost hydrogen sensors for multiple applications. This work is valuable for studies of nanocarbon-gas reaction mechanisms and the work function properties in adsorption related applications, including field emission, hydrogen storage, energy cells, and gas sensing.

  20. A guide to potential soil carbon sequestration; land-use management for mitigation of greenhouse gas emissions

    USGS Publications Warehouse

    Markewich, H.W.; Buell, G.R.

    2001-01-01

    Terrestrial carbon sequestration has a potential role in reducing the recent increase in atmospheric carbon dioxide (CO2) that is, in part, contributing to global warming. Because the most stable long-term surface reservoir for carbon is the soil, changes in agriculture and forestry can potentially reduce atmospheric CO2 through increased soil-carbon storage. If local governments and regional planning agencies are to effect changes in land-use management that could mitigate the impacts of increased greenhouse gas (GHG) emissions, it is essential to know how carbon is cycled and distributed on the landscape. Only then can a cost/benefit analysis be applied to carbon sequestration as a potential land-use management tool for mitigation of GHG emissions. For the past several years, the U.S. Geological Survey (USGS) has been researching the role of terrestrial carbon in the global carbon cycle. Data from these investigations now allow the USGS to begin to (1) 'map' carbon at national, regional, and local scales; (2) calculate present carbon storage at land surface; and (3) identify those areas having the greatest potential to sequester carbon.

  1. Nitrous oxide emissions from intensively managed agroecosystems: the role of carbon inputs (Invited)

    NASA Astrophysics Data System (ADS)

    Castellano, M. J.; Iqbal, J.; Mitchell, D. C.; Basche, A.; Parkin, T.; Miguez, F.; Kaspar, T.

    2013-12-01

    In agroecosystems, many reports demonstrate a positive relationship between N2O emissions and N fertilizer inputs. This relationship has been incorporated into the IPCC model estimate of N2O emissions and implies that inorganic N availability limits N2O emissions. However, evidence indicates that denitrification accounts for most N2O emissions from agroecosystems and N2O production from denitrification requires reduced C in addition to oxidized N. Using two experiments and meta-analysis we highlight the potential importance of reduced carbon availability for N¬2O emissions from agroecosystems. Experiments were conducted in maize-based cropping systems, restored prairies and perennial vegetation buffers in Iowa, USA. These systems have high soil organic C (SOC) concentrations. In the first experiment, a cover crop preceding maize increased N2O emissions despite immobilizing large amounts of NO3. Laboratory incubations of these soils demonstrated that glucose, but not NO3, increased N2O emissions. Because the cover crop had no detectable effect on total or potentially mineralizable SOC, these results indicate that the relatively small cover crop C input increased N2O emissions from this system. In a second experiment that compared land uses (maize, restored prairies, and perennial vegetation buffers) with significant differences in total SOC (2.3, 2.8 and 3.0% C, respectively), 15N tracer application demonstrated the increase in SOC across land uses was associated with more complete denitrification to N2 rather than an increase in N immobilization or N2O emissions. Results from these experiments suggest a complex interaction between NO3 and potentially mineralizable C affects denitrification emissions of N2O and particularly the N2O/(N2+N2O) ratio: although a small plant-based C input increased N2O emissions in a NO3-rich soil, a larger long-term increase in total SOC reduced N2O emissions by decreasing the N2O/(N2+N2O) ratio. Consistent with our cover crop

  2. Probabilistic quantification of allowable carbon emissions for meeting multiple climate targets

    NASA Astrophysics Data System (ADS)

    Steinacher, M.; Joos, F.; Stocker, T. F.

    2013-12-01

    Climate targets are designed to inform policies that would limit the magnitude and impacts of climate change caused by anthropogenic emissions of greenhouse gases and other substances. The target that is currently recognized by most world governments places a limit of two degrees Celsius on the global mean warming since preindustrial times. This would require large sustained reductions in carbon dioxide emissions during the twenty-first century and beyond. Such a global temperature target, however, is not sufficient to control many other quantities, such as transient sea level rise, ocean acidification, and net primary production on land. Here, using an Earth system model of intermediate complexity (EMIC) in an observation-informed Bayesian approach, we show that allowable carbon emissions are substantially reduced when multiple climate targets are set. We take into account uncertainties in physical and carbon cycle model parameters, radiative efficiencies, climate sensitivity, and carbon cycle feedbacks by varying nineteen key model parameters. A broad set of site-specific and gridded observational data from atmosphere, ocean, and land is used to constrain the model ensemble to realizations that are compatible with observations. Within this framework, we explore a broad range of economically feasible greenhouse gas scenarios from the integrated assessment community to determine the likelihood of meeting a combination of specific global and regional targets under various assumptions. For any given likelihood of meeting a set of such targets, the allowable cumulative emissions are greatly reduced from those inferred from the temperature target alone. Therefore, temperature targets alone are unable to comprehensively limit the risks from anthropogenic emissions.

  3. Global Fire emissions and its impacts on terrestrial ecosystem carbon budget from 1901 to 2010

    NASA Astrophysics Data System (ADS)

    Yang, J.; Tian, H.; Tao, B.; Ren, W.; Wang, Y.; Liu, Y.

    2014-12-01

    As a natural disturbance in the earth system, fire plays a critical role in determining vegetation composition and distribution, atmospheric components, terrestrial carbon budget, and land surface energy balance, which all contribute to climate change. However, the fire regime prior to satellite era (the 1980s) is largely unknown at global level due to the lack of sufficient long-term fire records. Recently, a centurial-scale burned area dataset has been reconstructed at global level based on satellite information and fire model simulation. By incorporating this fire dataset into the Dynamic Land Ecosystem Model (DLEM), we estimated the fire emissions from global fires and analyzed the changes in terrestrial ecosystem carbon budget caused by fire during 1901 - 2010. Our preliminary results indicated that the average global fire emissions is 3.0 Pg C year-1 with a significantly decreasing trend during the study period. The difference between fire-on and fire-off simulations showed that fires reduced both net primary productivity (NPP) and ecosystem heterotrophic respiration (Rh). The immediate post-fire reduction in NPP is stronger than that in Rh, which dampened the Net Ecosystem Productivity; while the long-term post-fire recovery in NPP is much faster than that in Rh. Overall, the post-fire recovery processes sequestrated approximately 50% of the carbon emissions released from fires; the global fire cause a net carbon source at about 1.5 Pg C year-1 during the 110 years. In the 21st century, a large increase in global fire potential and burned area has been reported by previous studies according to climate projections. Our results imply that the future fires regime could produce more GHG emissions and reduce carbon sink size, which in turn cause positive feedbacks to global warming.

  4. Climate warming feedback from mountain birch forest expansion: reduced albedo dominates carbon uptake.

    PubMed

    de Wit, Heleen A; Bryn, Anders; Hofgaard, Annika; Karstensen, Jonas; Kvalevåg, Maria M; Peters, Glen P

    2014-07-01

    Expanding high-elevation and high-latitude forest has contrasting climate feedbacks through carbon sequestration (cooling) and reduced surface reflectance (warming), which are yet poorly quantified. Here, we present an empirically based projection of mountain birch forest expansion in south-central Norway under climate change and absence of land use. Climate effects of carbon sequestration and albedo change are compared using four emission metrics. Forest expansion was modeled for a projected 2.6 °C increase in summer temperature in 2100, with associated reduced snow cover. We find that the current (year 2000) forest line of the region is circa 100 m lower than its climatic potential due to land-use history. In the future scenarios, forest cover increased from 12% to 27% between 2000 and 2100, resulting in a 59% increase in biomass carbon storage and an albedo change from 0.46 to 0.30. Forest expansion in 2100 was behind its climatic potential, forest migration rates being the primary limiting factor. In 2100, the warming caused by lower albedo from expanding forest was 10 to 17 times stronger than the cooling effect from carbon sequestration for all emission metrics considered. Reduced snow cover further exacerbated the net warming feedback. The warming effect is considerably stronger than previously reported for boreal forest cover, because of the typically low biomass density in mountain forests and the large changes in albedo of snow-covered tundra areas. The positive climate feedback of high-latitude and high-elevation expanding forests with seasonal snow cover exceeds those of afforestation at lower elevation, and calls for further attention of both modelers and empiricists. The inclusion and upscaling of these climate feedbacks from mountain forests into global models is warranted to assess the potential global impacts. PMID:24343906

  5. Global organic carbon emissions from primary sources from 1960 to 2009

    NASA Astrophysics Data System (ADS)

    Huang, Ye; Shen, Huizhong; Chen, Yilin; Zhong, Qirui; Chen, Han; Wang, Rong; Shen, Guofeng; Liu, Junfeng; Li, Bengang; Tao, Shu

    2015-12-01

    In an attempt to reduce uncertainty, global organic carbon (OC) emissions from a total of 70 sources were compiled at 0.1° × 0.1° resolution for 2007 (PKU-OC-2007) and country scale from 1960 to 2009. The compilation took advantage of a new fuel-consumption data product (PKU-Fuel-2007) and a series of newly published emission factors (EFOC) in developing countries. The estimated OC emissions were 32.9 Tg (24.1-50.6 Tg as interquartile range), of which less than one third was anthropogenic in origin. Uncertainty resulted primarily from variations in EFOC. Asia, Africa, and South America had high emissions mainly because of residential biomass fuel burning or wildfires. Per-person OC emission in rural areas was three times that of urban areas because of the relatively high EFOC of residential solid fuels. Temporal trend of anthropogenic OC emissions depended on rural population, and was influenced primarily by residential crop residue and agricultural waste burning. Both the OC/PM2.5 ratio and emission intensity, defined as quantity of OC emissions per unit of fuel consumption for all sources, of anthropogenic OC followed a decreasing trend, indicating continuous improvement in combustion efficiency and control measures.

  6. Carbon-, sulfur-, and phosphorus-based charge transfer reactions in inductively coupled plasma-atomic emission spectrometry

    NASA Astrophysics Data System (ADS)

    Grindlay, Guillermo; Gras, Luis; Mora, Juan; de Loos-Vollebregt, Margaretha T. C.

    2016-01-01

    In this work, the influence of carbon-, sulfur-, and phosphorus-based charge transfer reactions on the emission signal of 34 elements (Ag, Al, As, Au, B, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, Ga, Hg, I, In, Ir, K, Li, Mg, Mn, Na, Ni, P, Pb, Pd, Pt, S, Sb, Se, Sr, Te, and Zn) in axially viewed inductively coupled plasma-atomic emission spectrometry has been investigated. To this end, atomic and ionic emission signals for diluted glycerol, sulfuric acid, and phosphoric acid solutions were registered and results were compared to those obtained for a 1% w w- 1 nitric acid solution. Experimental results show that the emission intensities of As, Se, and Te atomic lines are enhanced by charge transfer from carbon, sulfur, and phosphorus ions. Iodine and P atomic emission is enhanced by carbon- and sulfur-based charge transfer whereas the Hg atomic emission signal is enhanced only by carbon. Though signal enhancement due to charge transfer reactions is also expected for ionic emission lines of the above-mentioned elements, no experimental evidence has been found with the exception of Hg ionic lines operating carbon solutions. The effect of carbon, sulfur, and phosphorus charge transfer reactions on atomic emission depends on (i) wavelength characteristics. In general, signal enhancement is more pronounced for electronic transitions involving the highest upper energy levels; (ii) plasma experimental conditions. The use of robust conditions (i.e. high r.f. power and lower nebulizer gas flow rates) improves carbon, sulfur, and phosphorus ionization in the plasma and, hence, signal enhancement; and (iii) the presence of other concomitants (e.g. K or Ca). Easily ionizable elements reduce ionization in the plasma and consequently reduce signal enhancement due to charge transfer reactions.

  7. A "carbonizing dragon": China's fast growing CO2 emissions revisited.

    PubMed

    Minx, Jan C; Baiocchi, Giovanni; Peters, Glen P; Weber, Christopher L; Guan, Dabo; Hubacek, Klaus

    2011-11-01

    China's annual CO(2) emissions grew by around 4 billion tonnes between 1992 and 2007. More than 70% of this increase occurred between 2002 and 2007. While growing export demand contributed more than 50% to the CO(2) emission growth between 2002 and 2005, capital investments have been responsible for 61% of emission growth in China between 2005 and 2007. We use structural decomposition analysis to identify the drivers for China's emission growth between 1992 and 2007, with special focus on the period 2002 to 2007 when growth was most rapid. In contrast to previous analysis, we find that efficiency improvements have largely offset additional CO(2) emissions from increased final consumption between 2002 and 2007. The strong increases in emissions growth between 2002 and 2007 are instead explained by structural change in China's economy, which has newly emerged as the third major emission driver. This structural change is mainly the result of capital investments, in particular, the growing prominence of construction services and their carbon intensive supply chain. By closing the model for capital investment, we can now show that the majority of emissions embodied in capital investment are utilized for domestic household and government consumption (35-49% and 19-36%, respectively) with smaller amounts for the production of exports (21-31%). Urbanization and the associated changes in lifestyle are shown to be more important than other socio-demographic drivers like the decreasing household size or growing population. We argue that mitigation efforts will depend on the future development of these key drivers, particularly capital investments which dictate future mitigation costs. PMID:21888374

  8. Carbon soundings: greenhouse gas emissions of the UK music industry

    NASA Astrophysics Data System (ADS)

    Bottrill, C.; Liverman, D.; Boykoff, M.

    2010-01-01

    Over the past decade, questions regarding how to reduce human contributions to climate change have become more commonplace and non-nation state actors—such as businesses, non-government organizations, celebrities—have increasingly become involved in climate change mitigation and adaptation initiatives. For these dynamic and rapidly expanding spaces, this letter provides an accounting of the methods and findings from a 2007 assessment of greenhouse gas (GHG) emissions in the UK music industry. The study estimates that overall GHG emissions associated with the UK music market are approximately 540 000 t CO2e per annum. Music recording and publishing accounted for 26% of these emissions (138 000 t CO2e per annum), while three-quarters (74%) derived from activities associated with live music performances (400 000 t CO2e per annum). These results have prompted a group of music industry business leaders to design campaigns to reduce the GHG emissions of their supply chains. The study has also provided a basis for ongoing in-depth research on CD packaging, audience travel, and artist touring as well as the development of a voluntary accreditation scheme for reducing GHG emissions from activities of the UK music industry.

  9. High rates of anaerobic methane oxidation in freshwater wetlands reduce potential atmospheric methane emissions.

    PubMed

    Segarra, K E A; Schubotz, F; Samarkin, V; Yoshinaga, M Y; Hinrichs, K-U; Joye, S B

    2015-01-01

    The role of anaerobic oxidation of methane (AOM) in wetlands, the largest natural source of atmospheric methane, is poorly constrained. Here we report rates of microbially mediated AOM (average rate=20 nmol cm(-3) per day) in three freshwater wetlands that span multiple biogeographical provinces. The observed AOM rates rival those in marine environments. Most AOM activity may have been coupled to sulphate reduction, but other electron acceptors remain feasible. Lipid biomarkers typically associated with anaerobic methane-oxidizing archaea were more enriched in (13)C than those characteristic of marine systems, potentially due to distinct microbial metabolic pathways or dilution with heterotrophic isotope signals. On the basis of this extensive data set, AOM in freshwater wetlands may consume 200 Tg methane per year, reducing their potential methane emissions by over 50%. These findings challenge precepts surrounding wetland carbon cycling and demonstrate the environmental relevance of an anaerobic methane sink in ecosystems traditionally considered strong methane sources. PMID:26123199

  10. Removal of floral microbiota reduces floral terpene emissions

    NASA Astrophysics Data System (ADS)

    Peñuelas, Josep; Farré-Armengol, Gerard; Llusia, Joan; Gargallo-Garriga, Albert; Rico, Laura; Sardans, Jordi; Terradas, Jaume; Filella, Iolanda

    2014-10-01

    The emission of floral terpenes plays a key role in pollination in many plant species. We hypothesized that the floral phyllospheric microbiota could significantly influence these floral terpene emissions because microorganisms also produce and emit terpenes. We tested this hypothesis by analyzing the effect of removing the microbiota from flowers. We fumigated Sambucus nigra L. plants, including their flowers, with a combination of three broad-spectrum antibiotics and measured the floral emissions and tissular concentrations in both antibiotic-fumigated and non-fumigated plants. Floral terpene emissions decreased by ca. two thirds after fumigation. The concentration of terpenes in floral tissues did not decrease, and floral respiration rates did not change, indicating an absence of damage to the floral tissues. The suppression of the phyllospheric microbial communities also changed the composition and proportion of terpenes in the volatile blend. One week after fumigation, the flowers were not emitting β-ocimene, linalool, epoxylinalool, and linalool oxide. These results show a key role of the floral phyllospheric microbiota in the quantity and quality of floral terpene emissions and therefore a possible key role in pollination.

  11. Removal of floral microbiota reduces floral terpene emissions

    PubMed Central

    Peñuelas, Josep; Farré-Armengol, Gerard; Llusia, Joan; Gargallo-Garriga, Albert; Rico, Laura; Sardans, Jordi; Terradas, Jaume; Filella, Iolanda

    2014-01-01

    The emission of floral terpenes plays a key role in pollination in many plant species. We hypothesized that the floral phyllospheric microbiota could significantly influence these floral terpene emissions because microorganisms also produce and emit terpenes. We tested this hypothesis by analyzing the effect of removing the microbiota from flowers. We fumigated Sambucus nigra L. plants, including their flowers, with a combination of three broad-spectrum antibiotics and measured the floral emissions and tissular concentrations in both antibiotic-fumigated and non-fumigated plants. Floral terpene emissions decreased by ca. two thirds after fumigation. The concentration of terpenes in floral tissues did not decrease, and floral respiration rates did not change, indicating an absence of damage to the floral tissues. The suppression of the phyllospheric microbial communities also changed the composition and proportion of terpenes in the volatile blend. One week after fumigation, the flowers were not emitting β-ocimene, linalool, epoxylinalool, and linalool oxide. These results show a key role of the floral phyllospheric microbiota in the quantity and quality of floral terpene emissions and therefore a possible key role in pollination. PMID:25335793

  12. Including carbon emissions from deforestation in the carbon footprint of Brazilian beef.

    PubMed

    Cederberg, Christel; Persson, U Martin; Neovius, Kristian; Molander, Sverker; Clift, Roland

    2011-03-01

    Effects of land use changes are starting to be included in estimates of life-cycle greenhouse gas (GHG) emissions, so-called carbon footprints (CFs), from food production. Their omission can lead to serious underestimates, particularly for meat. Here we estimate emissions from the conversion of forest to pasture in the Legal Amazon Region (LAR) of Brazil and present a model to distribute the emissions from deforestation over products and time subsequent to the land use change. Expansion of cattle ranching for beef production is a major cause of deforestation in the LAR. The carbon footprint of beef produced on newly deforested land is estimated at more than 700 kg CO(2)-equivalents per kg carcass weight if direct land use emissions are annualized over 20 years. This is orders of magnitude larger than the figure for beef production on established pasture on non-deforested land. While Brazilian beef exports have originated mainly from areas outside the LAR, i.e. from regions not subject to recent deforestation, we argue that increased production for export has been the key driver of the pasture expansion and deforestation in the LAR during the past decade and this should be reflected in the carbon footprint attributed to beef exports. We conclude that carbon footprint standards must include the more extended effects of land use changes to avoid giving misleading information to policy makers, retailers, and consumers. PMID:21280649

  13. Effect of Carbon Nanotubes Upon Emissions From Cutting and Sanding Carbon Fiber-Epoxy Composites

    PubMed Central

    Heitbrink, William A.; Lo, Li-Ming

    2015-01-01

    Carbon nanotubes (CNTs) are being incorporated into structural composites to enhance material strength. During fabrication or repair activities, machining nanocomposites may release CNTs into the workplace air. An experimental study was conducted to evaluate the emissions generated by cutting and sanding on three types of epoxy-composite panels: Panel A containing graphite fibers, Panel B containing graphite fibers and carbon-based mat, and Panel C containing graphite fibers, carbon-based mat, and multi-walled CNTs. Aerosol sampling was conducted with direct-reading instruments, and filter samples were collected for measuring elemental carbon (EC) and fiber concentrations. Our study results showed that cutting Panel C with a band saw did not generate detectable emissions of fibers inspected by transmission electron microscopy but did increase the particle mass, number, and EC emission concentrations by 20% to 80% compared to Panels A and B. Sanding operation performed on two Panel C resulted in fiber emission rates of 1.9×108 and 2.8×106 fibers per second (f/s), while no free aerosol fibers were detected from sanding Panels A and B containing no CNTs. These free CNT fibers may be a health concern. However, the analysis of particle and EC concentrations from these same samples cannot clearly indicate the presence of CNTs, because extraneous aerosol generation from machining the composite epoxy material increased the mass concentrations of the EC. PMID:26478716

  14. Carbon nanotube based field emission X-ray sources

    NASA Astrophysics Data System (ADS)

    Cheng, Yuan

    This dissertation describes the development of field emission (FE) x-ray sources with a carbon-nanotube (CNT) cathode. Field emission x-rays have advantages over conventional x-rays by replacing the thermionic cathode with a cold cathode so that electrons are emitted at room temperature and emission is voltage controllable. CNTs are found to be excellent electron emitters with low threshold fields and high current density which makes them ideal for generate field emission x-rays. Macroscopic CNT cold cathodes are prepared and the parameters to tune their field emission properties are studied: structure and morphology of CNT cathodes, temperature as well as electronic work function of CNT. Macroscopic CNT cathodes with optimized performance are chosen to build a high-resolution x-ray imaging system. The system can readily generate x-ray radiation with continuous variation of temporal resolution up to nanoseconds and spatial resolution down to 10 micron. Its potential applications for dynamic x-ray imaging and micro-computed tomography are also demonstrated. The performance characteristics of this compact and versatile system are promising for non-destructive testing and for non-invasive small-animal imaging for biomedical research.

  15. Exploring a suitable nitrogen fertilizer rate to reduce greenhouse gas emissions and ensure rice yields in paddy fields.

    PubMed

    Zhong, Yiming; Wang, Xiaopeng; Yang, Jingping; Zhao, Xing; Ye, Xinyi

    2016-09-15

    The application rate of nitrogen fertilizer was believed to dramatically influence greenhouse gas (GHG) emissions from paddy fields. Thus, providing a suitable nitrogen fertilization rate to ensure rice yields, reducing GHG emissions and exploring emission behavior are important issues for field management. In this paper, a two year experiment with six rates (0, 75, 150, 225, 300, 375kgN/ha) of nitrogen fertilizer application was designed to examine GHG emissions by measuring carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O) flux and their cumulative global warming potential (GWP) from paddy fields in Hangzhou, Zhejiang in 2013 and 2014. The results indicated that the GWP and rice yields increased with an increasing application rate of nitrogen fertilizer. Emission peaks of CH4 mainly appeared at the vegetative phase, and emission peaks of CO2, and N2O mainly appeared at reproductive phase of rice growth. The CO2 flux was significantly correlated with soil temperature, while the CH4 flux was influenced by logging water remaining period and N2O flux was significantly associated with nitrogen application rates. This study showed that 225kgN/ha was a suitable nitrogen fertilizer rate to minimize GHG emissions with low yield-scaled emissions of 3.69 (in 2013) and 2.23 (in 2014) kg CO2-eq/kg rice yield as well as to ensure rice yields remained at a relatively high level of 8.89t/ha in paddy fields. PMID:27179680

  16. Reduced Nitrous Oxide Emissions in Tomato Cropping Systems under Drip Irrigation and Fertigation

    NASA Astrophysics Data System (ADS)

    Kennedy, T.; Suddick, E. C.; Six, J. W.

    2011-12-01

    In California, agriculture and forestry account for 8% of the total greenhouse gas (GHG) emissions, of which 50% is accounted for by nitrous oxide (N2O). Furrow irrigation and high temperatures in the Central Valley, together with conventional fertilization, are ideal for the production of food, but also N2O. These conditions lead to high N2O fluxes, but also mean there is great potential to reduce N2O emissions by optimizing fertilizer use and irrigation practices. Improving fertilizer use by better synchronizing nitrogen (N) availability and crop demand can reduce N losses and fertilizer costs. Smaller, more frequent fertilizer applications can increase the synchrony between available soil N and crop N uptake. Fertigation allows for more control over how much N is being added and can therefore allow for better synchrony throughout the growing season. In our study, we determined how management practices, such as fertilization, irrigation, tillage and harvest, affect direct N2O emissions in typical tomato cropping systems. We evaluated two contrasting irrigation managements and their associated fertilizer application method, i.e. furrow irrigation and knife injection versus drip irrigation and fertigation. Across two tomato-growing seasons, we found that shifts in fertilizer and irrigation water management directly affect GHG emissions. Seasonal N2O fluxes were 3.4 times lower under drip versus furrow irrigation. In 2010, estimated losses of fertilizer N as N2O were 0.60 ± 0.06 kg N2O-N ha-1 yr-1 in the drip system versus 2.06 ± 0.11 N2O-N kg ha-1 yr-1 in the furrow system, which was equivalent to 0.29% and 0.87% of the added fertilizer, respectively. Carbon dioxide (CO2) emissions were also lower in the drip system (2.21 ± 0.16 Mg CO2-C ha-1 yr-1) than the furrow system (4.65 ± 0.23 Mg CO2-C ha-1 yr-1). Soil mineral N, dissolved organic carbon and soil moisture also varied between the two systems and correlated positively with N2O and CO2 emissions, depending

  17. Analysis of alternative pathways for reducing nitrogen oxide emissions

    EPA Science Inventory

    Strategies for reducing tropospheric ozone typically include modifying combustion processes to reduce the formation of nitrogen oxides (NOx) and applying control devices that remove NOx from the exhaust gases of power plants, industrial sources and vehicles. For portions of the ...

  18. OPTIMIZING TECHNOLOGY TO REDUCE MERCURY AND ACID GAS EMISSIONS FROM ELECTRIC POWER PLANTS

    SciTech Connect

    Jeffrey C. Quick; David E. Tabet; Sharon Wakefield; Roger L. Bon

    2005-10-01

    Maps showing potential mercury, sulfur, chlorine, and moisture emissions for U.S. coal by county of origin were made from publicly available data (plates 1, 2, 3, and 4). Published equations that predict mercury capture by emission control technologies used at U.S. coal-fired utilities were applied to average coal quality values for 169 U.S. counties. The results were used to create five maps that show the influence of coal origin on mercury emissions from utility units with: (1) hot-side electrostatic precipitator (hESP), (2) cold-side electrostatic precipitator (cESP), (3) hot-side electrostatic precipitator with wet flue gas desulfurization (hESP/FGD), (4) cold-side electrostatic precipitator with wet flue gas desulfurization (cESP/FGD), and (5) spray-dry adsorption with fabric filter (SDA/FF) emission controls (plates 5, 6, 7, 8, and 9). Net (lower) coal heating values were calculated from measured coal Btu values, and estimated coal moisture and hydrogen values; the net heating values were used to derive mercury emission rates on an electric output basis (plate 10). Results indicate that selection of low-mercury coal is a good mercury control option for plants having hESP, cESP, or hESP/FGD emission controls. Chlorine content is more important for plants having cESP/FGD or SDA/FF controls; optimum mercury capture is indicated where chlorine is between 500 and 1000 ppm. Selection of low-sulfur coal should improve mercury capture where carbon in fly ash is used to reduce mercury emissions. Comparison of in-ground coal quality with the quality of commercially mined coal indicates that existing coal mining and coal washing practice results in a 25% reduction of mercury in U.S. coal before it is delivered to the power plant. Further pre-combustion mercury reductions may be possible, especially for coal from Texas, Ohio, parts of Pennsylvania and much of the western U.S.

  19. Airborne reduced nitrogen: ammonia emissions from agriculture and other sources.

    PubMed

    Anderson, Natalie; Strader, Ross; Davidson, Cliff

    2003-06-01

    Ammonia is a basic gas and one of the most abundant nitrogen-containing compounds in the atmosphere. When emitted, ammonia reacts with oxides of nitrogen and sulfur to form particles, typically in the fine particle size range. Roughly half of the PM(2.5) mass in eastern United States is ammonium sulfate, according to the US EPA. Results from recent studies of PM(2.5) show that these fine particles are typically deposited deep in the lungs and may lead to increased morbidity and/or mortality. Also, these particles are in the size range that will degrade visibility. Ammonia emission inventories are usually constructed by multiplying an activity level by an experimentally determined emission factor for each source category. Typical sources of ammonia include livestock, fertilizer, soils, forest fires and slash burning, industry, vehicles, the oceans, humans, pets, wild animals, and waste disposal and recycling activities. Livestock is the largest source category in the United States, with waste from livestock responsible for about 3x10(9) kg of ammonia in 1995. Volatilization of ammonia from livestock waste is dependent on many parameters, and thus emission factors are difficult to predict. Despite a seasonal variation in these values, the emission factors for general livestock categories are usually annually averaged in current inventories. Activity levels for livestock are from the USDA Census of Agriculture, which does not give information about animal raising practices such as housing types and grazing times, waste handling systems, and approximate animal slurry spreading times or methods. Ammonia emissions in the United States in 1995 from sources other than livestock are much lower; for example, annual emissions are roughly 8x10(8) kg from fertilizer, 7x10(7) kg from industry, 5x10(7) kg from vehicles and 1x10(8) kg from humans. There is considerable uncertainty in the emissions from soil and vegetation, although this category may also be significant

  20. Global Biogenic Emission of Carbon Dioxide from Landfills

    NASA Astrophysics Data System (ADS)

    Lima, R.; Nolasco, D.; Meneses, W.; Salazar, J.; Hernández, P.; Pérez, N.

    2002-12-01

    Human-induced increases in the atmospheric concentrations of greenhouse gas components have been underway over the past century and are expected to drive climate change in the coming decades. Carbon dioxide was responsible for an estimated 55 % of the antropogenically driven radiactive forcing of the atmosphere in the 1980s and is predicted to have even greater importance over the next century (Houghton et al., 1990). A highly resolved understanding of the sources and sinks of atmospheric CO2, and how they are affected by climate and land use, is essential in the analysis of the global carbon cycle and how it may be impacted by human activities. Landfills are biochemical reactors that produce CH4 and CO2 emissions due to anaerobic digestion of solid urban wastes. Estimated global CH4 emission from landfills is about 44 millions tons per year and account for a 7.4 % of all CH4 sources (Whiticar, 1989). Observed CO2/CH4 molar ratios from landfill gases lie within the range of 0.7-1.0; therefore, an estimated global biogenic emission of CO2 from landfills could reach levels of 11.2-16 millions tons per year. Since biogas extraction systems are installed for extracting, purifying and burning the landfill gases, most of the biogenic gas emission to the atmosphere from landfills occurs through the surface environment in a diffuse and disperse form, also known as non-controlled biogenic emission. Several studies of non-controlled biogenic gas emission from landfills showed that CO2/CH4 weight ratios of surface landfill gases, which are directly injected into the atmosphere, are about 200-300 times higher than those observed in the landfill wells, which are usually collected and burned by gas extraction systems. This difference between surface and well landfill gases is mainly due to bacterial oxidation of the CH4 to CO2 inducing higher CO2/CH4 ratios for surface landfill gases than those well landfill gases. Taking into consideration this observation, the global biogenic

  1. Implications of carbon dust emission for terrestrail carbon cycling and carbon accounting

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wind erosion preferentially removes the finest carbon- and nutrient-rich soil fractions, and consequently its role may be significant within terrestrial carbon (C) cycles. However, the impacts of wind erosion on soil organic carbon (SOC) redistribution are not considered in most carbon cycle models,...

  2. Radiative Forcing associated with Particulate Carbon Emissions resulting from the Use of Mercury Control Technology

    NASA Astrophysics Data System (ADS)

    Clack, H.; Penner, J. E.; Lin, G.

    2013-12-01

    Mercury is a persistent, toxic metal that bio-accumulates within the food web and causes neurological damage and fetal defects in humans. The U.S. was the first country to regulate the leading anthropogenic source of mercury into the atmosphere: coal combustion for electric power generation. The U.S. EPA's 2005 Clean Air Mercury Rule (CAMR) was replaced and further tightened in 2012 by the Mercury and Air Toxics Standard (MATS), which required existing coal-fired utilities to reduce their mercury emissions by approximately 90% by 2015. Outside the U.S., the Governing Council of the United Nations Environment Programme (UNEP) has passed the legally binding Minamata global mercury treaty that compels its signatory countries to prevent and reduce the emission and release of mercury. The most mature technology for controlling mercury emissions from coal combustion is the injection into the flue gas of powdered activated carbon (PAC) adsorbents having chemically treated surfaces designed to rapidly oxidize and adsorb mercury. However, such PAC is known to have electrical properties that make it difficult to remove from flue gas via electrostatic precipitation, by far the most common particulate control technology used in countries such as the U.S., India, and China which rely heavily on coal for power generation. As a result, PAC used to control mercury emissions can be emitted into the atmosphere, the sub-micron fraction of which may result in unintended radiative forcing similar to black carbon (BC). Here, we estimate the potential increases in secondary BC emissions, those not produced from combustion but arising instead from the use of injected PAC for mercury emission reduction. We also calculate the radiative forcing associated with these secondary BC emissions by using a global atmospheric chemical transport model coupled with a radiative transfer model.

  3. Sunlight-induced carbon dioxide emissions from inland waters

    NASA Astrophysics Data System (ADS)

    Koehler, Birgit; Landelius, Tomas; Weyhenmeyer, Gesa A.; Machida, Nanako; Tranvik, Lars J.

    2014-07-01

    The emissions of carbon dioxide (CO2) from inland waters are substantial on a global scale. Yet the fundamental question remains open which proportion of these CO2 emissions is induced by sunlight via photochemical mineralization of dissolved organic carbon (DOC), rather than by microbial respiration during DOC decomposition. Also, it is unknown on larger spatial and temporal scales how photochemical mineralization compares to other C fluxes in the inland water C cycle. We combined field and laboratory data with atmospheric radiative transfer modeling to parameterize a photochemical rate model for each day of the year 2009, for 1086 lakes situated between latitudes from 55°N to 69°N in Sweden. The sunlight-induced production of dissolved inorganic carbon (DIC) averaged 3.8 ± 0.04 g C m-2 yr-1, which is a flux comparable in size to the organic carbon burial in the lake sediments. Countrywide, 151 ± 1 kt C yr-1 was produced by photochemical mineralization, corresponding to about 12% of total annual mean CO2 emissions from Swedish lakes. With a median depth of 3.2 m, the lakes were generally deep enough that incoming, photochemically active photons were absorbed in the water column. This resulted in a linear positive relationship between DIC photoproduction and the incoming photon flux, which corresponds to the absorbed photons. Therefore, the slope of the regression line represents the wavelength- and depth-integrated apparent quantum yield of DIC photoproduction. We used this relationship to obtain a first estimate of DIC photoproduction in lakes and reservoirs worldwide. Global DIC photoproduction amounted to 13 and 35 Mt C yr-1 under overcast and clear sky, respectively. Consequently, these directly sunlight-induced CO2 emissions contribute up to about one tenth to the global CO2 emissions from lakes and reservoirs, corroborating that microbial respiration contributes a substantially larger share than formerly thought, and generate annual C fluxes similar in

  4. Carbon stocks of intact mangroves and carbon emissions arising from their conversion in the Dominican Republic.

    PubMed

    Kauffman, J Boone; Heider, Chris; Norfolk, Jennifer; Payton, Frederick

    2014-04-01

    Mangroves are recognized to possess a variety of ecosystem services including high rates of carbon sequestration and storage. Deforestation and conversion of these ecosystems continue to be high and have been predicted to result in significant carbon emissions to the atmosphere. Yet few studies have quantified the carbon stocks or losses associated with conversion of these ecosystems. In this study we quantified the ecosystem carbon stocks of three common mangrove types of the Caribbean as well as those of abandoned shrimp ponds in areas formerly occupied by mangrove-a common land-use conversion of mangroves throughout the world. In the mangroves of the Montecristi Province in Northwest Dominican Republic we found C stocks ranged from 706 to 1131 Mg/ha. The medium-statured mangroves (3-10 m in height) had the highest C stocks while the tall (> 10 m) mangroves had the lowest ecosystem carbon storage. Carbon stocks of the low mangrove (shrub) type (< 3 m) were relatively high due to the presence of carbon-rich soils as deep as 2 m. Carbon stocks of abandoned shrimp ponds were 95 Mg/ha or approximately 11% that of the mangroves. Using a stock-change approach, the potential emissions from the conversion of mangroves to shrimp ponds ranged from 2244 to 3799 Mg CO2e/ha (CO2 equivalents). This is among the largest measured C emissions from land use in the tropics. The 6260 ha of mangroves and converted mangroves in the Montecristi Province are estimated to contain 3,841,490 Mg of C. Mangroves represented 76% of this area but currently store 97% of the carbon in this coastal wetland (3,696,722 Mg C). Converted lands store only 4% of the total ecosystem C (144,778 Mg C) while they comprised 24% of the area. By these metrics the replacement of mangroves with shrimp and salt ponds has resulted in estimated emissions from this region totaling 3.8 million Mg CO2e or approximately 21% of the total C prior to conversion. Given the high C stocks of mangroves, the high emissions

  5. Reduced carbon uptake during the 2010 Northern Hemisphere summer from GOSAT

    NASA Astrophysics Data System (ADS)

    Guerlet, S.; Basu, S.; Butz, A.; Krol, M.; Hahne, P.; Houweling, S.; Hasekamp, O. P.; Aben, I.

    2013-05-01

    Column-averaged dry air mole fractions of carbon dioxide (XCO2) measured by the Greenhouse Gases Observing Satellite (GOSAT) reveal significant interannual variation (IAV) of CO2uptake during the Northern Hemisphere summer between 2009 and 2010. The XCO2drawdown in 2010 is shallower than in 2009 by 2.4 ppm and 3.0 ppm over North America and Eurasia, respectively. Reduced carbon uptake in the summer of 2010 is most likely due to the heat wave in Eurasia driving biospheric fluxes and fire emissions. A joint inversion of GOSAT and surface data estimates an integrated biospheric and fire emission anomaly in April-September of 0.89 ±0.20 PgC over Eurasia. In contrast, inversions of surface measurements alone fail to replicate the observed XCO2IAV and underestimate emission IAV over Eurasia. This shows the value of GOSAT XCO2in constraining the response of land-atmosphere exchange of CO2 to climate events.

  6. Potential climate engineering effectiveness and side effects during a high carbon dioxide-emission scenario.

    PubMed

    Keller, David P; Feng, Ellias Y; Oschlies, Andreas

    2014-01-01

    The realization that mitigation efforts to reduce carbon dioxide emissions have, until now, been relatively ineffective has led to an increasing interest in climate engineering as a possible means of preventing the potentially catastrophic consequences of climate change. While many studies have addressed the potential effectiveness of individual methods there have been few attempts to compare them. Here we use an Earth system model to compare the effectiveness and side effects of afforestation, artificial ocean upwelling, ocean iron fertilization, ocean alkalinization and solar radiation management during a high carbon dioxide-emission scenario. We find that even when applied continuously and at scales as large as currently deemed possible, all methods are, individually, either relatively ineffective with limited (<8%) warming reductions, or they have potentially severe side effects and cannot be stopped without causing rapid climate change. Our simulations suggest that the potential for these types of climate engineering to make up for failed mitigation may be very limited. PMID:24569320

  7. Potential climate engineering effectiveness and side effects during a high carbon dioxide-emission scenario

    PubMed Central

    Keller, David P.; Feng, Ellias Y.; Oschlies, Andreas

    2014-01-01

    The realization that mitigation efforts to reduce carbon dioxide emissions have, until now, been relatively ineffective has led to an increasing interest in climate engineering as a possible means of preventing the potentially catastrophic consequences of climate change. While many studies have addressed the potential effectiveness of individual methods there have been few attempts to compare them. Here we use an Earth system model to compare the effectiveness and side effects of afforestation, artificial ocean upwelling, ocean iron fertilization, ocean alkalinization and solar radiation management during a high carbon dioxide-emission scenario. We find that even when applied continuously and at scales as large as currently deemed possible, all methods are, individually, either relatively ineffective with limited (<8%) warming reductions, or they have potentially severe side effects and cannot be stopped without causing rapid climate change. Our simulations suggest that the potential for these types of climate engineering to make up for failed mitigation may be very limited. PMID:24569320

  8. Irreversible climate change due to carbon dioxide emissions.

    PubMed

    Solomon, Susan; Plattner, Gian-Kasper; Knutti, Reto; Friedlingstein, Pierre

    2009-02-10

    The severity of damaging human-induced climate change depends not only on the magnitude of the change but also on the potential for irreversibility. This paper shows that the climate change that takes place due to increases in carbon dioxide concentration is largely irreversible for 1,000 years after emissions stop. Following cessation of emissions, removal of atmospheric carbon dioxide decreases radiative forcing, but is largely compensated by slower loss of heat to the ocean, so that atmospheric temperatures do not drop significantly for at least 1,000 years. Among illustrative irreversible impacts that should be expected if atmospheric carbon dioxide concentrations increase from current levels near 385 parts per million by volume (ppmv) to a peak of 450-600 ppmv over the coming century are irreversible dry-season rainfall reductions in several regions comparable to those of the "dust bowl" era and inexorable sea level rise. Thermal expansion of the warming ocean provides a conservative lower limit to irreversible global average sea level rise of at least 0.4-1.0 m if 21st century CO(2) concentrations exceed 600 ppmv and 0.6-1.9 m for peak CO(2) concentrations exceeding approximately 1,000 ppmv. Additional contributions from glaciers and ice sheet contributions to future sea level rise are uncertain but may equal or exceed several meters over the next millennium or longer. PMID:19179281

  9. Irreversible climate change due to carbon dioxide emissions

    PubMed Central

    Solomon, Susan; Plattner, Gian-Kasper; Knutti, Reto; Friedlingstein, Pierre

    2009-01-01

    The severity of damaging human-induced climate change depends not only on the magnitude of the change but also on the potential for irreversibility. This paper shows that the climate change that takes place due to increases in carbon dioxide concentration is largely irreversible for 1,000 years after emissions stop. Following cessation of emissions, removal of atmospheric carbon dioxide decreases radiative forcing, but is largely compensated by slower loss of heat to the ocean, so that atmospheric temperatures do not drop significantly for at least 1,000 years. Among illustrative irreversible impacts that should be expected if atmospheric carbon dioxide concentrations increase from current levels near 385 parts per million by volume (ppmv) to a peak of 450–600 ppmv over the coming century are irreversible dry-season rainfall reductions in several regions comparable to those of the “dust bowl” era and inexorable sea level rise. Thermal expansion of the warming ocean provides a conservative lower limit to irreversible global average sea level rise of at least 0.4–1.0 m if 21st century CO2 concentrations exceed 600 ppmv and 0.6–1.9 m for peak CO2 concentrations exceeding ≈1,000 ppmv. Additional contributions from glaciers and ice sheet contributions to future sea level rise are uncertain but may equal or exceed several meters over the next millennium or longer. PMID:19179281

  10. Innovative Technology Reduces Power Plant Emissions - Commercialization Success

    NASA Technical Reports Server (NTRS)

    Parrish, Clyde

    2004-01-01

    Emission control system development includes: (1) Development of new oxidizer scrubber system to eliminate NOx waste and produce fertilizer (2) Technology licensed and a 1 to 3 MWatt-scale prototype installed on. power plant (3) Development of method to oxidize NO. to N02 (4) Experience gained from licensing NASA technology

  11. Innovative Technology Reduces Power Plant Emissions-Commercialization Success

    NASA Technical Reports Server (NTRS)

    Parrish, Clyde; Chung, Landy

    2004-01-01

    Overview of emission control system development: (1) Development of new oxidizer scrubber system to eliminate NOx waste and produce fertilizer (2) Technology licensed and a 1 to 3 MWatt-scale prototype installed on power plant (3) Development of method to oxidize NO to NO2 (4) Experience gained from licensing NASA technology.

  12. Surface application of biochar to reduce chloropicrin emissions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biochar is the carbon-enriched and porous material produced by heating organic material under conditions of limited or no oxygen. As biochar has a large surface area and strong sorption capacity, it can enhance the sequestration of organic contaminants such as pesticides in soil. Chloropicrin (CP) i...

  13. Final Report: Wireless Instrument for Automated Measurement of Clean Cookstove Usage and Black Carbon Emissions

    SciTech Connect

    Lukac, Martin; Ramanathan, Nithya; Graham, Eric

    2013-09-10

    Black carbon (BC) emissions from traditional cooking fires and other sources are significant anthropogenic drivers of radiative forcing. Clean cookstoves present a more energy-efficient and cleaner-burning vehicle for cooking than traditional wood-burning stoves, yet many existing cookstoves reduce emissions by only modest amounts. Further research into cookstove use, fuel types, and verification of emissions is needed as adoption rates for such stoves remain low. Accelerated innovation requires techniques for measuring and verifying such cookstove performance. The overarching goal of the proposed program was to develop a low-cost, wireless instrument to provide a high-resolution profile of the cookstove BC emissions and usage in the field. We proposed transferring the complexity of analysis away from the sampling hardware at the measurement site and to software at a centrally located server to easily analyze data from thousands of sampling instruments. We were able to build a low-cost field-based instrument that produces repeatable, low-cost estimates of cookstove usage, fuel estimates, and emission values with low variability. Emission values from our instrument were consistent with published ranges of emissions for similar stove and fuel types.

  14. Impact of inland shipping emissions on elemental carbon concentrations near waterways in The Netherlands

    NASA Astrophysics Data System (ADS)

    Keuken, M. P.; Moerman, M.; Jonkers, J.; Hulskotte, J.; Denier van der Gon, H. A. C.; Hoek, G.; Sokhi, R. S.

    2014-10-01

    This study aims to quantify the impact of black carbon from inland shipping on air quality, expressed as elemental carbon (EC) near inland waterways in The Netherlands. Downwind measurements of particle numbers and EC were used to establish emission factors for EC from inland shipping using inverse modelling. These emission factors were combined with data on energy consumption to derive annual average emissions rates for all Dutch waterways. A line source model was applied to compute the contribution of inland shipping to annual average EC concentrations for around 140,000 people living within 200 m of busy waterways in The Netherlands. The results showed that they are exposed to additional EC concentrations of up to 0.5 μg EC per m3 depending on the shipping volume and distance from the waterway. In view of the envisaged growth in water transport, this underlines the need to reduce combustion emissions from inland shipping. Targeting “gross” polluters may be the most effective approach since 30% of ships cause more than 80% of the total emissions.

  15. The Measurement of Landfill Gas Emissions with the Orbiting Carbon Observatory and CarbonSAT Satellites

    NASA Astrophysics Data System (ADS)

    Vigil, S. A.; Bovensmann, H.

    2010-12-01

    Landfill gas is a significant contributor to anthropogenic emissions of CH4 and CO2. The U.S. Environmental Protection Agency has estimated the total U.S. 2007 emissions of the CH4 component of landfill gas at 132.9 Tg CO2 Equivalent. This compares to total CH4 emission from all US sources in 2007 at 585.3 Tg CO2 Equivalent. Worldwide CH4 emissions from landfill gas have been estimated at 668 Tg CO2 Equivalent. Satellite remote sensing can also be used to characterize landfill gas emissions. The NASA Orbiting Carbon Observatory (OCO-2) and the proposed CarbonSAT (University of Bremen) satellites are particularly suited for this purpose. The Orbiting Carbon Observatory (OCO) was designed to provided high spatial resolution ( < 3 km2 footprints) and high accuracy ( 0.5 to 3 ppm) CO2 measurements. The original OCO satellite failed to achieve orbit in February 2009. A replacement satellite (OCO-2) is under construction and scheduled for launch in February 2013. These characteristics will allow the measurement of CO2 emissions from large landfills on the orbit path. Because surface landfill gas emissions include both CH4 and CO2 , the CH4 concentration can be inferred from CO2 concentrations. The CarbonSAT satellite which is being designed by the University of Bremen, Institute for Environmental Physics, has similar characteristics to OCO-2 but it has been optimized for measurement of both CH4 and CO2 . Key specifications for the CarbonSAT satellite include XCO2 single measurement error of < 1 to 3 ppm and XCH4 single measurement error of < 10 to 18 ppb. These characteristics will make it possible to detect both CO2 and CH4 emissions from large landfills. The spatial resolution and accuracy of the CO2 measurements from OCO-2 and CO2 and CH4 measurements from CarbonSAT present a unique opportunity to measure landfill gas emissions from large landfills such as exist in the United States and other developed countries. In general, landfills in the developed countries have

  16. Quantifying the emissions and air quality co-benefits of lower-carbon electricity production

    NASA Astrophysics Data System (ADS)

    Plachinski, Steven D.; Holloway, Tracey; Meier, Paul J.; Nemet, Gregory F.; Rrushaj, Arber; Oberman, Jacob T.; Duran, Phillip L.; Voigt, Caitlin L.

    2014-09-01

    The impact of air emissions from electricity generation depends on the spatial distribution of power plants and electricity dispatch decisions. Thus, any realistic evaluation of the air quality impacts of lower-carbon electricity must account for the spatially heterogeneous changes in associated emissions. Here, we present an analysis of the changes in fine particulate matter (PM2.5) associated with current, expected, and proposed energy efficiency and renewable energy policies in Wisconsin. We simulate the state's electricity system and its potential response to policies using the MyPower electricity-sector model, which calculates plant-by-plant reductions in NOx and SO2 emissions. We find that increased efficiency and renewable generation in a 2024 policy scenario substantially reduce statewide emissions of NOx and SO2 (55% and 59% compared to 2008, 32% and 33% compared to 2024 business-as-usual, BAU). PM2.5 is quantified across the Great Lakes region using the EPA Community Multiscale Air Quality (CMAQ) model for some emissions scenarios. We find that summer mean surface concentrations of sulfate and PM2.5 are less sensitive to policy changes than emissions. In the 2024 policy scenario, sulfate aerosol decreases less than 3% over most of the region relative to BAU and 3-13% relative to 2008 over most of Wisconsin. The lower response of these secondary aerosols arises from chemical and meteorological processing of electricity emissions, and mixing with other emission sources. An analysis of model performance and response to emission reduction at five sites in Wisconsin shows good model agreement with observations and a high level of spatial and temporal variability in sulfate and PM2.5 reductions. In this case study, the marginal improvements in emissions and air quality associated with carbon policies were less than the technology, renewable, and conservation assumptions under a business-as-usual scenario. However, this analysis for Wisconsin shows how

  17. Global Carbon Emissions in the Coming Decades: The Case of China

    SciTech Connect

    Levine, Mark; Levine, Mark D.; Aden, Nathaniel T.

    2008-05-01

    China's annual energy-related carbon emissions surpassed those of the United States in In order to build a more robust understanding of China's energy-related carbon emissions, emissions after 2001? The divergence between actual and forecasted carbon emissions international trade, and central government policies in driving emissions growth. so greatly in error and what drove the rapid growth of China's energy-related carbon this article reviews the role of economic restructuring, urbanization, coal dependence, underscores the rapid changes that have taken place in China's energy system since 2001.

  18. Global carbon emissions in the coming decades: the case of China

    SciTech Connect

    Levine, M.D.; Aderi, N.T.

    2008-07-01

    China's annual energy-related carbon emissions surpassed those of the United States in 2006, years ahead of published international and Chinese forecasts. Why were forecasts so greatly in error and what drove the rapid growth of China's energy-related carbon emissions after 2001? The divergence between actual and forecasted carbon emissions underscores the rapid changes that have taken place in China's energy system since 2001. In order to build a more robust understanding of China's energy-related carbon emissions, this article reviews the role of economic restructuring, urbanization, coal dependence, international trade, and central government policies in driving emissions growth.

  19. 40 CFR 600.008 - Review of fuel economy, CO2 emissions, and carbon-related exhaust emission data, testing by the...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., and carbon-related exhaust emission data, testing by the Administrator. 600.008 Section 600.008... emissions, and carbon-related exhaust emission data, testing by the Administrator. (a) Testing by the... promptly as possible. (ii) Starting with the 2012 model year for carbon-related exhaust emissions and...

  20. Reducing health care's carbon footprint--the power of nursing.

    PubMed

    Muñoz, Aliria

    2012-11-01

    Global warming and environmentalism continue to be national and international issues as their complexities and implications become better understood. One ironic contributor to the degradation of the environment is the health care system. Serving as clinical laboratories, hotels, restaurants, and offices that never close, U.S. hospitals produce more than 2 million tons of waste annually. Although the consequences and significance of health care's carbon footprint are undeniable, strategies to reduce this impact are challenging. This article discusses how the role, traits, and knowledge of nurses combined with their positions in the health care system make them key players in creating an environmentally sustainable health care industry. With an analysis of environmental action versus inaction, this article explores how nurses at the forefront of health care are equipped to change practice that will reach far beyond the bedside. PMID:23413481

  1. Inductive pulsed phase thermography for reducing or enlarging the effect of surface emissivity variation

    NASA Astrophysics Data System (ADS)

    Yang, Ruizhen; He, Yunze; Gao, Bin; Tian, Gui Yun

    2014-11-01

    Emissivity variation introduces illusory temperature inhomogeneity and results in false alarms in infrared thermography, thus, it is important to separate the influence of surface emissivity variation. This letter experimentally demonstrates the advantages of phase information to reduce or enlarge the effect of surface emissivity variation with inductive pulsed phase thermography, where inductive excitation is emissivity-independent and avoids the effect of emissivity variation in heating process. The directly heated area and the indirectly heated area are divided in the phasegrams. The emissivity variation is removed or enlarged perfectly at the specific frequency and defect detectability is improved remarkably.

  2. The IR emission features - Emission from PAH molecules and amorphous carbon particles

    NASA Technical Reports Server (NTRS)

    Allamandola, L. J.; Tielens, A. G. G. M.; Barker, J. R.

    1987-01-01

    Given the current understanding of polycyclic aromatic hydrocarbons (PAHs), the spectroscopic data suggest that are at least two components which contribute to the interstellar emission spectrum: (1) free molecule-sized PAHs producing the narrow features and (2) amorphous carbon particles (which are primarily composed of an irregular 'lattice' of PAHs) contributing to the broad underlying components. An exact treatment of the IR fluorescence from highly vibrationally excited large molecules demonstrates that species containing between 20 and 30 carbon atoms are responsible for the narrow features, although the spectra match more closely with the spectra of amorphous carbon particles. It is concluded that, since little is known about the spectroscopic properties of free PAHs and PAH clusters, much laboratory work is required along with an observational program focusing on the spatial characteristics of the spectra.

  3. Solvatochromism Unravels the Emission Mechanism of Carbon Nanodots.

    PubMed

    Sciortino, Alice; Marino, Emanuele; Dam, Bart van; Schall, Peter; Cannas, Marco; Messina, Fabrizio

    2016-09-01

    High quantum yield, photoluminescence tunability, and sensitivity to the environment are hallmarks that make carbon nanodots interesting for fundamental research and applications. Yet, the underlying electronic transitions behind their bright photoluminescence are strongly debated. Despite carbon-dot interactions with their environment should provide valuable insight into the emitting transitions, they have hardly been studied. Here, we investigate these interactions in a wide range of solvents to elucidate the nature of the electronic transitions. We find remarkable and systematic dependence of the emission energy and kinetics on the characteristics of the solvent, with strong response of the photoexcited dots to hydrogen bonding. These findings suggest that the fluorescence originates from the radiative recombination of a photoexcited electron migrated to surface groups with holes left in the valence band of the crystalline core. Furthermore, the results demonstrate the fluorescence tunability to inherently derive from dot-to-dot polydispersity, independent of solvent interactions. PMID:27525451

  4. Future development programs. [for defining the emission problem and developing hardware to reduce pollutant levels

    NASA Technical Reports Server (NTRS)

    Jedrziewski, S.

    1976-01-01

    The emission problem or source points were defined and new materials, hardware, or operational procedures were developed to exercise the trends defined by the data collected. The programs to reduce the emission output of aircraft powerplants were listed. Continued establishment of baseline emissions for various engine models, continued characterization of effect of production tolerances on emissions, carbureted engine development and flight tests, and cylinder cooling/fin design programs were several of the programs investigated.

  5. Reducing methane emissions in sheep by immunization against rumen methanogens.

    PubMed

    Wright, A D G; Kennedy, P; O'Neill, C J; Toovey, A F; Popovski, S; Rea, S M; Pimm, C L; Klein, L

    2004-09-28

    This work was conducted to determine if methane emissions from sheep immunized with an anti-methanogen vaccine were significantly lower than methane emissions from non-immunized sheep, to test the effectiveness of two different vaccine formulations (VF) on methane abatement, and to compare methane emissions measured using a closed-circuit respiration chamber and the sulphur-hexafluoride (SF6) tracer technique. Thirty mature wether sheep were randomly allocated to three treatment groups (n = 10). One group received an immunization of adjuvant only on days 0 and 153 (control), a second group received an immunization with a 3-methanogen mix on days 0 and 153 (VF3 + 3), and a third group received an immunization of a 7-methanogen mix on day 0 followed by a 3-methanogen mix on day 153 (VF7 + 3). Four weeks post-secondary immunization, there was a significant 7.7% reduction in methane production per kg dry matter intake in the VF7 + 3 group compared to the controls (P = 0.051). However, methane emissions from sheep immunized with VF7 + 3 were not significantly different when compared to the sheep in the control group (P = 0.883). The average IgG and IgA antibody titres in both plasma and saliva of the VF3 + 3 immunized sheep were four to nine times higher than those immunized with VF7 + 3 (P< 0.001) at both 3 and 6 weeks post-secondary immunization. Data also revealed that SF6 methane estimates were consistently higher than the respiration chamber estimates and that there was no significant correlation between the SF6 methane estimates and the respiration chamber methane estimates (R2 = 0.11). PMID:15364447

  6. 330 kWe Packaged CHP System with Reduced Emissions

    SciTech Connect

    Plahn, Paul; Keene, Kevin; Pendray, John

    2015-03-31

    The objective of this project was to develop a flexible, 330 kWe packaged Combined Heat and Power (CHP) system that can be deployed to commercial and light industrial applications at a lower total cost of ownership than current CHP solutions. The project resulted in a CHP system that is easy to use and inexpensive to install, offering world class customer support, while providing a low-emissions, higher-efficiency internal combustion engine for a CHP system of this size.

  7. Engineering Filters for Reducing Spontaneous Emission in cQED

    NASA Astrophysics Data System (ADS)

    Bronn, Nicholas; Masluk, Nicholas; Srinivasan, Srikanth; Chow, Jerry; Abraham, David; Rothwell, Mary; Keefe, George; Gambetta, Jay; Steffen, Matthias; Lirakis, Chris

    2014-03-01

    Inserting a notch filter between a qubit and the external environment at the qubit frequency can significantly suppress spontaneous emission mediated by the cavity (``Purcell effect''). In order to realize this filtering in multi-qubit architectures, where space comes at a premium, we will present a filter with minimal space requirements. We acknowledge support from IARPA under contract W911NF-10-1-0324.

  8. Thermal emission spectra from individual suspended carbon nanotubes.

    PubMed

    Liu, Zuwei; Bushmaker, Adam; Aykol, Mehmet; Cronin, Stephen B

    2011-06-28

    We study the thermal emission spectra of individual suspended carbon nanotubes induced by electrical heating. Semiconducting and metallic devices exhibit different spectra, based on their distinctive band structures. These spectra are compared with the ideal blackbody emission spectrum. In the visible wavelength range, the thermal emission spectra of semiconducting devices agree well with Planck's law, while the spectra of metallic devices show an additional peak between 1.5 and 1.9 eV. In the near-infrared wavelength range, the semiconducting nanotubes exhibit a peak around 1 eV. These additional peaks are attributed to the E11M and E22SC transitions that are thermally driven under these high applied bias voltages. These peaks show a strong polarization dependence, while the blackbody tail is unpolarized, which provides further evidence for electron-hole recombination in thermal emission. For semiconducting devices, the temperature of the nanotube is fit to Planck's law and compared with the temperatures obtained from the G band and 2D band Raman downshifts, as well as the anti-Stokes/Stokes intensity ratio. For devices showing thermal non-equilibrium, the electron temperature agrees well with G+ downshift but deviates from G_ downshift. PMID:21545117

  9. Carbon dioxide emission prediction using support vector machine

    NASA Astrophysics Data System (ADS)

    Saleh, Chairul; Rachman Dzakiyullah, Nur; Bayu Nugroho, Jonathan

    2016-02-01

    In this paper, the SVM model was proposed for predict expenditure of carbon (CO2) emission. The energy consumption such as electrical energy and burning coal is input variable that affect directly increasing of CO2 emissions were conducted to built the model. Our objective is to monitor the CO2 emission based on the electrical energy and burning coal used from the production process. The data electrical energy and burning coal used were obtained from Alcohol Industry in order to training and testing the models. It divided by cross-validation technique into 90% of training data and 10% of testing data. To find the optimal parameters of SVM model was used the trial and error approach on the experiment by adjusting C parameters and Epsilon. The result shows that the SVM model has an optimal parameter on C parameters 0.1 and 0 Epsilon. To measure the error of the model by using Root Mean Square Error (RMSE) with error value as 0.004. The smallest error of the model represents more accurately prediction. As a practice, this paper was contributing for an executive manager in making the effective decision for the business operation were monitoring expenditure of CO2 emission.

  10. Carbon dioxide emissions from Specchio di Venere, Pantelleria, Italy

    NASA Astrophysics Data System (ADS)

    Paz, Mariana P. Jácome; Inguaggiato, Salvatore; Taran, Yuri; Vita, Fabio; Pecoraino, Giovanella

    2016-04-01

    We have mapped the diffuse CO2 efflux from the Specchio di Venere Lake area using the accumulation chamber method. We calculated a CO2 emission of 43 ± 5 t day-1 for the area studied, accounting for both diffuse degassing from soil and bubbling through the lake. We also present data on the water composition of Specchio di Venere Lake, the Polla 3 spring, and Liuzza well. On the basis of water chemistry, two physical-chemical processes, evaporation and mineral precipitation of carbonate species, are invoked to explain the CO2 degassing for the lake area.

  11. Variability of ultraviolet emission in the carbon star TX Piscium

    NASA Technical Reports Server (NTRS)

    Johnson, Hollis R.; Baumert, John H.; Querci, Francois; Querci, Monique

    1986-01-01

    Multiple low-resolution IUE observations of the cool carbon star TX Psc (N0; C6, 2) permit an analysis of the variations in strength of the strongest emission lines - the Mg II line at 2800 A, the C II line at 2330 A, and certain Fe II lines. The integrated flux of the Mg II line varied by at least a factor of eight, while that of the C II line varies by at least a factor of five. The variations in Fe II may be considerably larger. The lines appear to vary together. The continuous flux in the best observed range from 2800 to 3200 A does not vary noticeably.

  12. 40 CFR 1036.610 - Innovative technology credits and adjustments for reducing greenhouse gas emissions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... the provisions of 40 CFR 86.1866-12(d)(3). However, we will generally not seek public comment on... adjustments for reducing greenhouse gas emissions. 1036.610 Section 1036.610 Protection of Environment... adjustments for reducing greenhouse gas emissions. (a) You may ask us to apply the provisions of this...

  13. 40 CFR 1036.610 - Innovative technology credits and adjustments for reducing greenhouse gas emissions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... the provisions of 40 CFR 86.1866-12(d)(3). However, we will generally not seek public comment on... adjustments for reducing greenhouse gas emissions. 1036.610 Section 1036.610 Protection of Environment... adjustments for reducing greenhouse gas emissions. (a) You may ask us to apply the provisions of this...

  14. 40 CFR 1036.610 - Innovative technology credits and adjustments for reducing greenhouse gas emissions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... the provisions of 40 CFR 86.1866-12(d)(3). However, we will generally not seek public comment on... adjustments for reducing greenhouse gas emissions. 1036.610 Section 1036.610 Protection of Environment... adjustments for reducing greenhouse gas emissions. (a) You may ask us to apply the provisions of this...

  15. Reducing Ammonia Emissions from Poultry Litter with Alum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aluminum sulfate (alum) additions to poultry litter have been shown to reduce ammonia (NH3) volatilization. The objectives of this paper were to present data on the effects of alum treatment of poultry litter on: (1) the efficacy of reducing ammonia loss, (2) poultry production parameters, and (3) ...

  16. Filtration of Carbon Particulate Emissions from a Plasma Pyrolysis Assembly

    NASA Technical Reports Server (NTRS)

    Agui, Juan H.; Green, Robert; Vijayakumar, R.; Berger, Gordon; Greenwood, Zach; Abney, Morgan; Peterson, Elspeth

    2016-01-01

    NASA is investigating plasma pyrolysis as a candidate technology that will enable the recovery of hydrogen from the methane produced by the ISS Sabatier Reactor. The Plasma Pyrolysis Assembly (PPA) is the current prototype of this technology which converts the methane product from the Carbon Dioxide Reduction Assembly (CRA) to acetylene and hydrogen with 90% or greater conversion efficiency. A small amount of solid carbon particulates are generated as a side product and must be filtered before the acetylene is removed and the hydrogen-rich gas stream is recycled back to the CRA. We discuss developmental work on several options for filtering out the carbon particulate emissions from the PPA exit gas stream. The filtration technologies and concepts investigated range from fibrous media to monolithic ceramic and sintered metal media. This paper describes the different developed filter prototypes and characterizes their performance from integrated testing at the Environmental Chamber (E-Chamber) at MSFC. In addition, characterization data on the generated carbon particulates, that help to define filter requirements, are also presented.

  17. Rapid carbon mineralization for permanent disposal of anthropogenic carbon dioxide emissions.

    PubMed

    Matter, Juerg M; Stute, Martin; Snæbjörnsdottir, Sandra Ó; Oelkers, Eric H; Gislason, Sigurdur R; Aradottir, Edda S; Sigfusson, Bergur; Gunnarsson, Ingvi; Sigurdardottir, Holmfridur; Gunnlaugsson, Einar; Axelsson, Gudni; Alfredsson, Helgi A; Wolff-Boenisch, Domenik; Mesfin, Kiflom; Fernandez de la Reguera Taya, Diana; Hall, Jennifer; Dideriksen, Knud; Broecker, Wallace S

    2016-06-10

    Carbon capture and storage (CCS) provides a solution toward decarbonization of the global economy. The success of this solution depends on the ability to safely and permanently store CO2 This study demonstrates for the first time the permanent disposal of CO2 as environmentally benign carbonate minerals in basaltic rocks. We find that over 95% of the CO2 injected into the CarbFix site in Iceland was mineralized to carbonate minerals in less than 2 years. This result contrasts with the common view that the immobilization of CO2 as carbonate minerals within geologic reservoirs takes several hundreds to thousands of years. Our results, therefore, demonstrate that the safe long-term storage of anthropogenic CO2 emissions through mineralization can be far faster than previously postulated. PMID:27284192

  18. Rapid carbon mineralization for permanent disposal of anthropogenic carbon dioxide emissions

    NASA Astrophysics Data System (ADS)

    Matter, Juerg M.; Stute, Martin; Snæbjörnsdottir, Sandra Ó.; Oelkers, Eric H.; Gislason, Sigurdur R.; Aradottir, Edda S.; Sigfusson, Bergur; Gunnarsson, Ingvi; Sigurdardottir, Holmfridur; Gunnlaugsson, Einar; Axelsson, Gudni; Alfredsson, Helgi A.; Wolff-Boenisch, Domenik; Mesfin, Kiflom; Taya, Diana Fernandez de la Reguera; Hall, Jennifer; Dideriksen, Knud; Broecker, Wallace S.

    2016-06-01

    Carbon capture and storage (CCS) provides a solution toward decarbonization of the global economy. The success of this solution depends on the ability to safely and permanently store CO2. This study demonstrates for the first time the permanent disposal of CO2 as environmentally benign carbonate minerals in basaltic rocks. We find that over 95% of the CO2 injected into the CarbFix site in Iceland was mineralized to carbonate minerals in less than 2 years. This result contrasts with the common view that the immobilization of CO2 as carbonate minerals within geologic reservoirs takes several hundreds to thousands of years. Our results, therefore, demonstrate that the safe long-term storage of anthropogenic CO2 emissions through mineralization can be far faster than previously postulated.

  19. The effects of defoliation on carbon allocation: can carbon limitation reduce growth in favour of storage?

    PubMed

    Wiley, Erin; Huepenbecker, Sarah; Casper, Brenda B; Helliker, Brent R

    2013-11-01

    There is no consensus about how stresses such as low water availability and temperature limit tree growth. Sink limitation to growth and survival is often inferred if a given stress does not cause non-structural carbohydrate (NSC) concentrations or levels to decline along with growth. However, trees may actively maintain or increase NSC levels under moderate carbon stress, making the pattern of reduced growth and increased NSCs compatible with carbon limitation. To test this possibility, we used full and half defoliation to impose severe and moderate carbon limitation on 2-year-old Quercus velutina Lam. saplings grown in a common garden. Saplings were harvested at either 3 weeks or 4 months after treatments were applied, representing short- and longer-term effects on woody growth and NSC levels. Both defoliation treatments maintained a lower total leaf area than controls throughout the experiment with no evidence of photosynthetic up-regulation, and resulted in a similar total biomass reduction. While fully defoliated saplings had lower starch levels than controls in the short term, half defoliated saplings maintained control starch levels in both the short and longer term. In the longer term, fully defoliated saplings had the greatest starch concentration increment, allowing them to recover to near-control starch levels. Furthermore, between the two harvest dates, fully and half defoliated saplings allocated a greater proportion of new biomass to starch than did controls. The maintenance of control starch levels in half defoliated saplings indicates that these trees actively store a substantial amount of carbon before growth is carbon saturated. In addition, the allocation shift favouring storage in defoliated saplings is consistent with the hypothesis that, as an adaptation to increasing carbon stress, trees can prioritize carbon reserve formation at the expense of growth. Our results suggest that as carbon limitation increases, reduced growth is not necessarily

  20. Plant acclimation impacts carbon allocation to isoprene emissions: evidence from past to future CO2 levels

    NASA Astrophysics Data System (ADS)

    de Boer, Hugo J.; van der Laan, Annick; Dekker, Stefan C.; Holzinger, Rupert

    2016-04-01

    Isoprene (C5H8) is produced in plant leaves as a side product of photosynthesis, whereby approximately 0.1-2.0% of the photosynthetic carbon uptake is released back into the atmosphere via isoprene emissions. Isoprene biosynthesis is thought to alleviate oxidative stress, specifically in warm, dry and high-light environments. Moreover, isoprene biosynthesis is influenced by atmospheric CO2 concentrations in the short term (weeks) via acclimation in photosynthetic biochemistry. In order to understand the effects of CO2-induced climate change on carbon allocation in plants it is therefore important to quantify how isoprene biosynthesis and emissions are effected by both short-term responses and long-term acclimation to rising atmospheric CO2 levels. A promising development for modelling CO2-induced changes in isoprene emissions is the Leaf-Energetic-Status model (referred to as LES-model hereafter, see Harrison et al., 2013 and Morfopoulos et al., 2014). This model simulates isoprene emissions based on the hypothesis that isoprene biosynthesis depends on the imbalance between the photosynthetic electron supply of reducing power and the electron demands of carbon fixation. In addition to environmental conditions, this imbalance is determined by the photosynthetic electron transport capacity (Jmax) and the maximum carboxylation capacity of Rubisco (V cmax). Here we compare predictions of the LES-model with observed isoprene emission responses of Quercus robur (pedunculate oak) specimen that acclimated to CO2 levels representative of the last glacial, the present and the end of this century (200, 400 and 800 ppm, respectively) for two growing seasons. Plants were grown in walk-in growth chambers with tight control of light, temperature, humidity and CO2 concentrations. Photosynthetic biochemical parameters V cmax and Jmax were determined with a Licor LI-6400XT photosynthesis system

  1. Potential of aeration flow rate and bio-char addition to reduce greenhouse gas and ammonia emissions during manure composting.

    PubMed

    Chowdhury, Md Albarune; de Neergaard, Andreas; Jensen, Lars Stoumann

    2014-02-01

    Aeration is an important factor influencing CO2, CH4, N2O and NH3 emissions from the composting process. Both CH4 and N2O are potent greenhouse gases (GHG) of high importance. Here, we examined the effects of high and low aeration rates together with addition of barley straw with and without bio-char on GHG and NH3 emissions from composting cattle slurry and hen manure in small-scale laboratory composters. Depending on treatment, cumulative C losses via CO2 and CH4 emissions accounted for 11.4-22.5% and 0.004-0.2% of initial total carbon, while N losses as N2O and NH3 emissions comprised 0.05-0.1% and 0.8-26.5% of initial total nitrogen, respectively. Decreasing the flow rate reduced cumulative NH3 losses non-significantly (by 88%) but significantly increased CH4 losses (by 51%) from composting of cattle slurry with barley straw. Among the hen manure treatments evaluated, bio-char addition to composting hen manure and barley straw at low flow rates proved most effective in reducing cumulative NH3 and CH4 losses. Addition of bio-char in combination with barley straw to hen manure at both high and low flow rates reduced total GHG emissions (as CO2-equivalents) by 27-32% compared with barley straw addition alone. Comparisons of flow rates showed that low flow could be an alternative strategy for reducing NH3 losses without any significant change in N2O emissions, pointing to the need for well-controlled composting conditions if gaseous emissions are to be minimised. PMID:24210550

  2. Emissions of black carbon and co-pollutants emitted from diesel vehicles in the Mexico City Metropolitan Area

    NASA Astrophysics Data System (ADS)

    Zavala, Miguel; Molina, Luisa T.; Fortner, Edward; Knighton, Berk; Herndon, Scott; Yacovitch, Tara; Floerchinger, Cody; Roscioli, Joseph; Kolb, Charles; Mejia, Jose Antonio; Sarmiento, Jorge; Paramo, Victor Hugo; Zirath, Sergio; Jazcilevich, Aron

    2014-05-01

    Black carbon emitted from freight, public transport, and heavy duty trucks sources is linked with adverse effects on human health. In addition, the control of emissions of black carbon, an important short-lived climate forcing agent (SLCF), has recently been considered as one of the key strategies for mitigating regional near-term climate change. Despite the availability of new emissions control technologies for reducing emissions from diesel-powered mobile sources, their introduction is still not widespread in many urban areas and there is a need to characterize real-world emission rates of black carbon from this key source. The emissions of black carbon, organic carbon, and other gaseous and particle pollutants from diesel-powered mobile sources in Mexico were characterized by deploying a mobile laboratory equipped with real-time instrumentation in Mexico City as part of the SLCFs-Mexico 2013 project. From February 25-28 of 2013 the emissions from selected diesel-powered vehicles were measured in both controlled experiments and real-world on-road driving conditions. Sampled vehicles had several emissions levels technologies, including: EPA98, EPA03, EPA04, EURO3-5, and Hybrid. All vehicles were sampled using diesel fuel and several vehicles were measured using both diesel and biodiesel fuels. Additional measurements included the use of a remote sensing unit for the co-sampling of all tested vehicles, and the installation and operation of a Portable Emissions Measurements System (PEMS) for the measurement of emissions from a test vehicle. We will present inter-comparisons of the emission factors obtained among the various vehicle technologies that were sampled during the experiment as well as the inter-comparison of results from the various sampling platforms. The results can be used to

  3. Reducing emissions from deforestation and forest degradation (REDD+): game changer or just another quick fix?

    PubMed

    Venter, Oscar; Koh, Lian Pin

    2012-02-01

    Reducing emissions from deforestation and forest degradation (REDD+) provides financial compensation to land owners who avoid converting standing forests to other land uses. In this paper, we review the main opportunities and challenges for REDD+ implementation, including expectations for REDD+ to deliver on multiple environmental and societal cobenefits. We also highlight a recent case study, the Norway-Indonesia REDD+ agreement and discuss how it might be a harbinger of outcomes in other forest-rich nations seeking REDD+ funds. Looking forward, we critically examine the fundamental assumptions of REDD+ as a solution for the atmospheric buildup of greenhouse gas emissions and tropical deforestation. We conclude that REDD+ is currently the most promising mechanism driving the conservation of tropical forests. Yet, to emerge as a true game changer, REDD+ must still demonstrate that it can access low transaction cost and high-volume carbon markets or funds, while also providing or complimenting a suite of nonmonetary incentives to encourage a developing nation's transition from forest losing to forest gaining, and align with, not undermine, a globally cohesive attempt to mitigate anthropogenic climate change. PMID:22168380

  4. An assessment of monitoring requirements and costs of 'Reduced Emissions from Deforestation and Degradation'

    PubMed Central

    Böttcher, Hannes; Eisbrenner, Katja; Fritz, Steffen; Kindermann, Georg; Kraxner, Florian; McCallum, Ian; Obersteiner, Michael

    2009-01-01

    Background Negotiations on a future climate policy framework addressing Reduced Emissions from Deforestation and Degradation (REDD) are ongoing. Regardless of how such a framework will be designed, many technical solutions of estimating forest cover and forest carbon stock change exist to support policy in monitoring and accounting. These technologies typically combine remotely sensed data with ground-based inventories. In this article we assess the costs of monitoring REDD based on available technologies and requirements associated with key elements of REDD policy. Results We find that the design of a REDD policy framework (and specifically its rules) can have a significant impact on monitoring costs. Costs may vary from 0.5 to 550 US$ per square kilometre depending on the required precision of carbon stock and area change detection. Moreover, they follow economies of scale, i.e. single country or project solutions will face relatively higher monitoring costs. Conclusion Although monitoring costs are relatively small compared to other cost items within a REDD system, they should be shared not only among countries but also among sectors, because an integrated monitoring system would have multiple benefits for non-REDD management. Overcoming initialization costs and unequal access to monitoring technologies is crucial for implementation of an integrated monitoring system, and demands for international cooperation. PMID:19709413

  5. Incorrect interpretation of carbon mass balance biases global vegetation fire emission estimates.

    PubMed

    Surawski, N C; Sullivan, A L; Roxburgh, S H; Meyer, C P Mick; Polglase, P J

    2016-01-01

    Vegetation fires are a complex phenomenon in the Earth system with many global impacts, including influences on global climate. Estimating carbon emissions from vegetation fires relies on a carbon mass balance technique that has evolved with two different interpretations. Databases of global vegetation fire emissions use an approach based on 'consumed biomass', which is an approximation to the biogeochemically correct 'burnt carbon' approach. Here we show that applying the 'consumed biomass' approach to global emissions from vegetation fires leads to annual overestimates of carbon emitted to the atmosphere by 4.0% or 100 Tg compared with the 'burnt carbon' approach. The required correction is significant and represents ∼9% of the net global forest carbon sink estimated annually. Vegetation fire emission studies should use the 'burnt carbon' approach to quantify and understand the role of this burnt carbon, which is not emitted to the atmosphere, as a sink enriched in carbon. PMID:27146785

  6. Incorrect interpretation of carbon mass balance biases global vegetation fire emission estimates

    NASA Astrophysics Data System (ADS)

    Surawski, N. C.; Sullivan, A. L.; Roxburgh, S. H.; Meyer, C. P. Mick; Polglase, P. J.

    2016-05-01

    Vegetation fires are a complex phenomenon in the Earth system with many global impacts, including influences on global climate. Estimating carbon emissions from vegetation fires relies on a carbon mass balance technique that has evolved with two different interpretations. Databases of global vegetation fire emissions use an approach based on `consumed biomass', which is an approximation to the biogeochemically correct `burnt carbon' approach. Here we show that applying the `consumed biomass' approach to global emissions from vegetation fires leads to annual overestimates of carbon emitted to the atmosphere by 4.0% or 100 Tg compared with the `burnt carbon' approach. The required correction is significant and represents ~9% of the net global forest carbon sink estimated annually. Vegetation fire emission studies should use the `burnt carbon' approach to quantify and understand the role of this burnt carbon, which is not emitted to the atmosphere, as a sink enriched in carbon.

  7. Warming reduces carbon losses from grassland exposed to elevated atmospheric carbon dioxide.

    PubMed

    Pendall, Elise; Heisler-White, Jana L; Williams, David G; Dijkstra, Feike A; Carrillo, Yolima; Morgan, Jack A; Lecain, Daniel R

    2013-01-01

    The flux of carbon dioxide (CO2) between terrestrial ecosystems and the atmosphere may ameliorate or exacerbate climate change, depending on the relative responses of ecosystem photosynthesis and respiration to warming temperatures, rising atmospheric CO2, and altered precipitation. The combined effect of these global change factors is especially uncertain because of their potential for interactions and indirectly mediated conditions such as soil moisture. Here, we present observations of CO2 fluxes from a multi-factor experiment in semi-arid grassland that suggests a potentially strong climate - carbon cycle feedback under combined elevated [CO2] and warming. Elevated [CO2] alone, and in combination with warming, enhanced ecosystem respiration to a greater extent than photosynthesis, resulting in net C loss over four years. The effect of warming was to reduce respiration especially during years of below-average precipitation, by partially offsetting the effect of elevated [CO2] on soil moisture and C cycling. Carbon losses were explained partly by stimulated decomposition of soil organic matter with elevated [CO2]. The climate - carbon cycle feedback observed in this semiarid grassland was mediated by soil water content, which was reduced by warming and increased by elevated [CO2]. Ecosystem models should incorporate direct and indirect effects of climate change on soil water content in order to accurately predict terrestrial feedbacks and long-term storage of C in soil. PMID:23977180

  8. Do volcanic emissions affect carbon gas fluxes in peatlands?

    NASA Astrophysics Data System (ADS)

    Harrison, Nicola; Delmelle, Pierre; Toet, Sylvia; Gauci, Vincent; Ineson, Phil

    2010-05-01

    Recently, a link has been suggested between volcanic deposition of SO4 and the suppression of CH4 emissions in northern peatlands (Gauci et al., 2008). This link stems from the widely accepted idea that acid rain SO4 additions to peatlands can cause a shift in microbial communities as SO4 reducing bacteria out-compete methanogens for substrates, which results in a suppression of CH4 emission. However, volcanic emissions contain besides S other chemically reactive species that are potentially harmful to the environment. In particular, gaseous and particulate F emissions from volcanoes constitute a steady or intermittent source of F emission and deposition into the environment both close to the source and within fallout range of large eruptions. The objective of this study was to investigate the effect of volcanic depositions of SO4, both alone and in combination with F, on CH4 emission in peatlands. Peat mesocosms collected from Pennine uplands in the UK were treated with weekly pulses of Na2SO4 and NaF over 20 weeks in doses of 74 kg SO4/ ha and 13.5 and 135 kg F /ha. CH4 emissions were measured at regular intervals by taking headspace samples, which were analysed by GC-FID. CO2 fluxes were also measured using a portable Infra Red Gas Analyser (IRGA). No significant differences in CH4 and CO2 emissions were observed for any of the treatments when compared to the controls, which had only received deionised water. These findings are in contrast with previous studies where SO4 reduces CH4 emission in peatlands. The reason for this is unclear but may be due to the heterogeneous nature of peat soils. An alternative explanation relates to the previous history of the soils used in the mesocosms which are known to have been previously exposed to large volumes of anthropogenic S pollution. This may have caused microbial communities to evolve and become acclimatised to high levels of S addition. In either case, the assumption that CH4 suppression in peatlands occurs upon

  9. Improving farming practices reduces the carbon footprint of spring wheat production

    PubMed Central

    Gan, Yantai; Liang, Chang; Chai, Qiang; Lemke, Reynald L.; Campbell, Con A.; Zentner, Robert P.

    2014-01-01

    Wheat is one of the world’s most favoured food sources, reaching millions of people on a daily basis. However, its production has climatic consequences. Fuel, inorganic fertilizers and pesticides used in wheat production emit greenhouse gases that can contribute negatively to climate change. It is unknown whether adopting alternative farming practices will increase crop yield while reducing carbon emissions. Here we quantify the carbon footprint of alternative wheat production systems suited to semiarid environments. We find that integrating improved farming practices (that is, fertilizing crops based on soil tests, reducing summerfallow frequencies and rotating cereals with grain legumes) lowers wheat carbon footprint effectively, averaging −256 kg CO2 eq ha−1 per year. For each kg of wheat grain produced, a net 0.027–0.377 kg CO2 eq is sequestered into the soil. With the suite of improved farming practices, wheat takes up more CO2 from the atmosphere than is actually emitted during its production. PMID:25405548

  10. Improving farming practices reduces the carbon footprint of spring wheat production

    NASA Astrophysics Data System (ADS)

    Gan, Yantai; Liang, Chang; Chai, Qiang; Lemke, Reynald L.; Campbell, Con A.; Zentner, Robert P.

    2014-11-01

    Wheat is one of the world’s most favoured food sources, reaching millions of people on a daily basis. However, its production has climatic consequences. Fuel, inorganic fertilizers and pesticides used in wheat production emit greenhouse gases that can contribute negatively to climate change. It is unknown whether adopting alternative farming practices will increase crop yield while reducing carbon emissions. Here we quantify the carbon footprint of alternative wheat production systems suited to semiarid environments. We find that integrating improved farming practices (that is, fertilizing crops based on soil tests, reducing summerfallow frequencies and rotating cereals with grain legumes) lowers wheat carbon footprint effectively, averaging -256 kg CO2 eq ha-1 per year. For each kg of wheat grain produced, a net 0.027-0.377 kg CO2 eq is sequestered into the soil. With the suite of improved farming practices, wheat takes up more CO2 from the atmosphere than is actually emitted during its production.

  11. Soil pH management without lime, a strategy to reduce greenhouse gas emissions from cultivated soils

    NASA Astrophysics Data System (ADS)

    Nadeem, Shahid; Bakken, Lars; Reent Köster, Jan; Tore Mørkved, Pål; Simon, Nina; Dörsch, Peter

    2015-04-01

    For decades, agricultural scientists have searched for methods to reduce the climate forcing of food production by increasing carbon sequestration in the soil and reducing the emissions of nitrous oxide (N2O). The outcome of this research is depressingly meagre and the two targets appear incompatible: efforts to increase carbon sequestration appear to enhance the emissions of N2O. Currently there is a need to find alternative management strategies which may effectively reduce both the CO2 and N2O footprints of food production. Soil pH is a master variable in soil productivity and plays an important role in controlling the chemical and biological activity in soil. Recent investigations of the physiology of denitrification have provided compelling evidence that the emission of N2O declines with increasing pH within the range 5-7. Thus, by managing the soil pH at a near neutral level appears to be a feasible way to reduce N2O emissions. Such pH management has been a target in conventional agriculture for a long time, since a near-neutral pH is optimal for a majority of cultivated plants. The traditional way to counteract acidification of agricultural soils is to apply lime, which inevitably leads to emission of CO2. An alternative way to increase the soil pH is the use of mafic rock powders, which have been shown to counteract soil acidification, albeit with a slower reaction than lime. Here we report a newly established field trail in Norway, in which we compare the effects of lime and different mafic mineral and rock powders (olivine, different types of plagioclase) on CO2 and N2O emissions under natural agricultural conditions. Soil pH is measured on a monthly basis from all treatment plots. Greenhouse gas (GHG) emission measurements are carried out on a weekly basis using static chambers and an autonomous robot using fast box technique. Field results from the first winter (fallow) show immediate effect of lime on soil pH, and slower effects of the mafic rocks. The

  12. Technology Opportunities to Reduce U.S. Greenhouse Gas Emissions

    SciTech Connect

    Not Available

    1997-10-01

    This report serves as the technology basis of a needed national climate change technology strategy, with the confidence that a strong technology R&D program will deliver a portfolio of technologies with the potential to provide very substantial greenhouse gas emission reductions along with continued economic growth. Much more is needed to define such a strategy, including identification of complementary deployment policies and analysis to support the seeping and prioritization of R&D programs. A national strategy must be based upon governmental, industrial, and academic partnerships.

  13. The impacts of electricity dispatch protocols on the emission reductions due to wind power and carbon tax.

    PubMed

    Yu, Yang; Rajagopal, Ram

    2015-02-17

    Two dispatch protocols have been adopted by electricity markets to deal with the uncertainty of wind power but the effects of the selection between the dispatch protocols have not been comprehensively analyzed. We establish a framework to compare the impacts of adopting different dispatch protocols on the efficacy of using wind power and implementing a carbon tax to reduce emissions. We suggest that a market has high potential to achieve greater emission reduction by adopting the stochastic dispatch protocol instead of the static protocol when the wind energy in the market is highly uncertain or the market has enough adjustable generators, such as gas-fired combustion generators. Furthermore, the carbon-tax policy is more cost-efficient for reducing CO2 emission when the market operates according to the stochastic protocol rather than the static protocol. An empirical study, which is calibrated according to the data from the Electric Reliability Council of Texas market, confirms that using wind energy in the Texas market results in a 12% CO2 emission reduction when the market uses the stochastic dispatch protocol instead of the 8% emission reduction associated with the static protocol. In addition, if a 6$/ton carbon tax is implemented in the Texas market operated according to the stochastic protocol, the CO2 emission is similar to the emission level from the same market with a 16$/ton carbon tax operated according to the static protocol. Correspondingly, the 16$/ton carbon tax associated with the static protocol costs 42.6% more than the 6$/ton carbon tax associated with the stochastic protocol. PMID:25607824

  14. Battery-Powered Electric and Hybrid Electric Vehicle Projects to Reduce Greenhouse Gas Emissions: A Resource for Project Development

    SciTech Connect

    National Energy Technology Laboratory

    2002-07-31

    The transportation sector accounts for a large and growing share of global greenhouse gas (GHG) emissions. Worldwide, motor vehicles emit well over 900 million metric tons of carbon dioxide (CO2) each year, accounting for more than 15 percent of global fossil fuel-derived CO2 emissions.1 In the industrialized world alone, 20-25 percent of GHG emissions come from the transportation sector. The share of transport-related emissions is growing rapidly due to the continued increase in transportation activity.2 In 1950, there were only 70 million cars, trucks, and buses on the world’s roads. By 1994, there were about nine times that number, or 630 million vehicles. Since the early 1970s, the global fleet has been growing at a rate of 16 million vehicles per year. This expansion has been accompanied by a similar growth in fuel consumption.3 If this kind of linear growth continues, by the year 2025 there will be well over one billion vehicles on the world’s roads.4 In a response to the significant growth in transportation-related GHG emissions, governments and policy makers worldwide are considering methods to reverse this trend. However, due to the particular make-up of the transportation sector, regulating and reducing emissions from this sector poses a significant challenge. Unlike stationary fuel combustion, transportation-related emissions come from dispersed sources. Only a few point-source emitters, such as oil/natural gas wells, refineries, or compressor stations, contribute to emissions from the transportation sector. The majority of transport-related emissions come from the millions of vehicles traveling the world’s roads. As a result, successful GHG mitigation policies must find ways to target all of these small, non-point source emitters, either through regulatory means or through various incentive programs. To increase their effectiveness, policies to control emissions from the transportation sector often utilize indirect means to reduce emissions, such

  15. Measurements of black and organic carbon emission factors for household coal combustion in China: implication for emission reduction.

    PubMed

    Chen, Yingjun; Zhi, Guorui; Feng, Yanli; Liu, Dongyan; Zhang, Gan; Li, Jun; Sheng, Guoying; Fu, Jiamo

    2009-12-15

    Household coal combustion is considered as the greatest emission source for black carbon (BC) and an important source for organic carbon (OC) in China. However, measurements on BC and OC emission factors (EF(BC) and EF(OC)) are still scarce, which result in large uncertainties in emission estimates. In this study, a detailed data set of EF(BC) and EF(OC) for household coal burning was presented on the basis of 38 coal/stove combination experiments. These experiments included 13 coals with a wide coverage of geological maturity which were tested in honeycomb-coal-briquette and raw-coal-chunk forms in three typical coal stoves. Averaged values of EF(BC) are 0.004 and 0.007 g/kg for anthracite in briquette and chunk forms and 0.09 and 3.05 g/kg for bituminous coal, respectively; EF(OC) are 0.06 and 0.10 g/kg for anthracite and 3.74 and 5.50 g/kg for bituminous coal in both forms, respectively. Coal maturity was found to be the most important influencing factor relative to coal's burning forms and the stove's burning efficiency, and when medium-volatile bituminous coals (MVB) are excluded from use, averaged EF(BC) and EF(OC) for bituminous coal decrease by 50% and 30%, respectively. According to these EFs, China's BC and OC emissions from the household sector in 2000 were 94 and 244 gigagrams (Gg), respectively. Compared with previous BC emission estimates for this sector (e.g., 465 Gg by Ohara et al., Atmos. Chem. Phys. 2007, 7, 4419-4444), a dramatic decrease was observed and was mainly attributed to the update of EFs. As suggested by this study, if MVB is prohibited as household fuel together with further promotion of briquettes, BC and OC emissions in this sector will be reduced by 80% and 34%, respectively, and then carbonaceous emissions can be controlled to a large extent in China. PMID:20000546

  16. The Seasonal and Spatial Distribution of Carbon Dioxide Emissions from Fossil Fuels in Asia

    NASA Astrophysics Data System (ADS)

    Gregg, J. S.; Andres, R. J.

    2006-12-01

    Carbon dioxide emissions from fossil-fuel consumption are presented for the five Asian countries that are among the global leaders in anthropogenic carbon emissions: China (13% of global total), Japan (5% of global total), India (5% of global total), South Korea (2% of global total), and Indonesia (1% of global total). Together, these five countries represent over a quarter of the world's fossil-fuel based carbon emissions. Moreover, these countries are rapidly developing and energy demand has grown dramatically in the last two decades. A method is developed to estimate the spatial and seasonal flux of fossil-fuel consumption, thereby greatly improving the temporal and spatial resolution of anthropogenic carbon dioxide emissions. Currently, only national annual data for anthropogenic carbon emissions are available, and as such, no understanding of seasonal or sub-national patterns of emissions are possible. This methodology employs fuel distribution data from representative sectors of the fossil-fuel market to determine the temporal and spatial patterns of fuel consumption. These patterns of fuel consumption are then converted to patterns of carbon emissions. The annual total emissions estimates produced by this method are consistent to those maintained by the United Nations. Improved estimates of temporal and spatial resolution of the human based carbon emissions allows for better projections about future energy demands, carbon emissions, and ultimately the global carbon cycle.

  17. Carbon, nitrogen balances and greenhouse gas emission during cattle feedlot manure composting.

    PubMed

    Hao, Xiying; Chang, Chi; Larney, Francis J

    2004-01-01

    Carbon and N losses reduce the agronomic value of compost and contribute to greenhouse gas (GHG) emissions. This study investigated GHG emissions during composting of straw-bedded manure (SBM) and wood chip-bedded manure (WBM). For SBM, dry matter (DM) loss was 301 kg Mg(-1), total carbon (TC) loss was 174 kg Mg(-1), and total nitrogen (TN) loss was 8.3 kg Mg(-1). These correspond to 30.1% of initial DM, 52.8% of initial TC, and 41.6% of initial TN. For WBM, DM loss was 268 kg Mg(-1), TC loss was 154 kg Mg(-1), and TN loss was 1.40 kg Mg(-1), corresponding to 26.5, 34.5, and 11.8% of initial amounts. Most C was lost as CO2 with CH4 accounting for <6%. However, the net contribution to greenhouse gas emissions was greater for CH4 since it is 21 times more effective at trapping heat than CO2. Nitrous oxide (N2O) emissions were 0.077 kg N Mg(-1) for SBM and 0.084 kg N Mg(-1) for WBM, accounting for 1 to 6% of total N loss. Total GHG emissions as CO2-C equivalent were not significantly different between SBM (368.4 +/- 18.5 kg Mg(-1)) and WBM (349.2 +/- 24.3 kg Mg(-1)). However, emission of 368.4 kg C Mg(-1) (CO2-C equivalent) was greater than the initial TC content (330.5 kg Mg(-1)) of SBM, raising the question of the net benefits of composting on C sequestration. Further study is needed to evaluate the impact of composting on overall GHG emissions and C sequestration and to fully investigate livestock manure management options. PMID:14964356

  18. Massive and prolonged deep carbon emissions associated with continental rifting

    NASA Astrophysics Data System (ADS)

    Lee, Hyunwoo; Muirhead, James D.; Fischer, Tobias P.; Ebinger, Cynthia J.; Kattenhorn, Simon A.; Sharp, Zachary D.; Kianji, Gladys

    2016-02-01

    Carbon from Earth’s interior is thought to be released to the atmosphere mostly via degassing of CO2 from active volcanoes. CO2 can also escape along faults away from active volcanic centres, but such tectonic degassing is poorly constrained. Here we use measurements of diffuse soil CO2, combined with carbon isotopic analyses to quantify the flux of CO2 through fault systems away from active volcanoes in the East African Rift system. We find that about 4 Mt yr-1 of mantle-derived CO2 is released in the Magadi-Natron Basin, at the border between Kenya and Tanzania. Seismicity at depths of 15-30 km implies that extensional faults in this region may penetrate the lower crust. We therefore suggest that CO2 is transferred from upper-mantle or lower-crustal magma bodies along these deep faults. Extrapolation of our measurements to the entire Eastern rift of the rift system implies a CO2 flux on the order of tens of megatonnes per year, comparable to emissions from the entire mid-ocean ridge system of 53-97 Mt yr-1. We conclude that widespread continental rifting and super-continent breakup could produce massive, long-term CO2 emissions and contribute to prolonged greenhouse conditions like those of the Cretaceous.

  19. Pyrogenic carbon emission from a large wildfire in Oregon, United States

    NASA Astrophysics Data System (ADS)

    Campbell, John; Donato, Dan; Azuma, David; Law, Beverly

    2007-12-01

    We used a ground-based approach to compute the pyrogenic carbon emissions from the Biscuit Fire, an exceptionally large wildfire, which in 2002 burned over 200,000 ha of mixed conifer forest in southwestern Oregon. A combination of federal inventory data and supplementary ground measurements afforded the estimation of preburn densities for 25 separate carbon pools at 180 independent locations in the burn area. Average combustion factors for each of these pools were then compiled from the postburn assessment of thousands of individual trees, shrubs, and parcels of surface and ground fuel. Combustion factors were highest for litter, duff, and foliage, lowest for live woody pools. Combustion factors also increased with burn severity as independently assessed from remote imagery, endorsing the use of such imagery in scaling emissions to fire area. We estimate the total pyrogenic carbon emissions from the Biscuit Fire to be between 3.5 and 4.4 Tg C (17 and 22 Mg C ha-1) depending on uncertainty in our ability to estimate preburn litter pools and mineral soil combustion with a central estimate of 3.8 Tg C (19 Mg C ha-1). We estimate that this flux is approximately 16 times the annual net ecosystem production of this landscape prior to the wildfire and may have reduced mean net biome production across the state of Oregon by nearly half in the year 2002.

  20. Decadal changes in carbon Emissions and sinks optimized using a Bayesian fusion of multiple observations.

    NASA Astrophysics Data System (ADS)

    Ciais, P.

    2015-12-01

    A better understanding of current human perturbation global carbon cycle is fundamental to support the projection of future climate change and designing better informed climate policy. making. Here, we develop a Bayesian approach that fuses different data-streams to optimize fossil fuel emission (F), land use change emission (L), land sink (B) and ocean sink (O) at a 5-year time step from 1980 to 2014. Here we show that the optimization decreases uncertainties compared with those of the carbon budget established by Global Carbon Project (GCP) and the IPCC where single datasets are used and the land sink deduced as a residual from other terms. Uncertainties of F, L, B and O are reduced by 11%, 26, 36% and 40% compared to those of the GCP budget. Fossil fuel and land use change emissions show a significantly increasing and decreasing trend, respectively, while no significant trend is detected for land and ocean uptakes. We infer with a 93% confidence that the net biosphere uptake with land use change (BL) has increased since 1980. After a further decomposition of the net land flux, sum of L and B, into gross terrestrial fluxes of primary productivity (GPP) and ecosystem respiration (TER), we attribute the increase of B+L to a faster growth of GPP than TER from 1980~1984 to 1990~1994 and a lower decreasing rate of GPP than TER in the 2000s. This approach can be potentially implemented on a yearly basis in future with growing observation-based datasets.

  1. Stable Electron Field Emission afrom Opened-Tip Carbon Nanotube Bundles

    NASA Astrophysics Data System (ADS)

    Pandey, Archana; Prasad, Abhishek; Moscatello, Jason; Khin Yap, Yoke

    2009-03-01

    Effective electron field emission from carbon nanotubes (CNTs) has been known for years but reliable commercial devices are still not available. Most reported works describe low emission threshold field (Eth) of CNTs and their device architectures. However, fundamental factors that determine stable emission from CNTs are still not clear. We previously reported that graphitic order of CNTs affects their emission stability [1]. Here, we found that both opened tip nanotubes and bundling, when introduced independently, can reduce Eth of CNTs and enhance the emission stability. The combined of both factors, i.e., opened tip nanotube bundles are shown to emit electron continuously > ten hours with notable stability. Theoretical simulation was conducted in supporting our explanation on these enhanced emission properties. SEM, TEM and Raman spectroscopy was conducted to characterize the as grown CNTs. Y. K. Yap acknowledges support from the Defense Advanced Research Projects Agency (DAAD17-03-C-0115, through Army Research Laboratory). [1]. Kayastha et al, Nanotechnology 18, 035206 (2007).

  2. Committed carbon emissions, deforestation, and community land conversion from oil palm plantation expansion in West Kalimantan, Indonesia

    PubMed Central

    Carlson, Kimberly M.; Curran, Lisa M.; Ratnasari, Dessy; Pittman, Alice M.; Soares-Filho, Britaldo S.; Asner, Gregory P.; Trigg, Simon N.; Gaveau, David A.; Lawrence, Deborah; Rodrigues, Hermann O.

    2012-01-01

    Industrial agricultural plantations are a rapidly increasing yet largely unmeasured source of tropical land cover change. Here, we evaluate impacts of oil palm plantation development on land cover, carbon flux, and agrarian community lands in West Kalimantan, Indonesian Borneo. With a spatially explicit land change/carbon bookkeeping model, parameterized using high-resolution satellite time series and informed by socioeconomic surveys, we assess previous and project future plantation expansion under five scenarios. Although fire was the primary proximate cause of 1989–2008 deforestation (93%) and net carbon emissions (69%), by 2007–2008, oil palm directly caused 27% of total and 40% of peatland deforestation. Plantation land sources exhibited distinctive temporal dynamics, comprising 81% forests on mineral soils (1994–2001), shifting to 69% peatlands (2008–2011). Plantation leases reveal vast development potential. In 2008, leases spanned ∼65% of the region, including 62% on peatlands and 59% of community-managed lands, yet <10% of lease area was planted. Projecting business as usual (BAU), by 2020 ∼40% of regional and 35% of community lands are cleared for oil palm, generating 26% of net carbon emissions. Intact forest cover declines to 4%, and the proportion of emissions sourced from peatlands increases 38%. Prohibiting intact and logged forest and peatland conversion to oil palm reduces emissions only 4% below BAU, because of continued uncontrolled fire. Protecting logged forests achieves greater carbon emissions reductions (21%) than protecting intact forests alone (9%) and is critical for mitigating carbon emissions. Extensive allocated leases constrain land management options, requiring trade-offs among oil palm production, carbon emissions mitigation, and maintaining community landholdings. PMID:22523241

  3. Sea spray geoengineering can reduce ocean net primary productivity and carbon uptake

    NASA Astrophysics Data System (ADS)

    Partanen, Antti-Ilari; Keller, David; Korhonen, Hannele; Matthews, Damon

    2016-04-01

    Sea spray geoengineering or marine cloud brightening is one of the proposed methods to deliberately increase planetary albedo and thus counteract climate change. Previous studies have shown that it has potential to significantly alter the global energy balance and reduce impacts on temperature and precipitation. However, its effects on ecosystems have received considerably less attention. Our goal is to assess the effects of sea spray geoengineering on marine biological productivity and global carbon cycle. We use the University of Victoria Earth System Climate Model (UVic ESCM) to simulate the effects of prescribed aerosol forcing from previous simulations with the aerosol-climate model ECHAM-HAMMOZ. In our baseline simulation (GEO), forcing from geoengineering was applied over three persistent stratocumulus regions off the coasts of North America, South America, and South Africa. The global mean forcing was -1 W m‑2. Other forcings and emissions were set according to the RCP4.5 scenario. The control run (CTRL) was identical to GEO except that no geoengineering was present. As a more extreme case, we simulated a scenario where forcing from geoengineering was applied over all ocean area (GEO-ALL) giving a global mean forcing of -4.9 W m‑2. Geoengineering decreased the global total ocean net primary productivity (NPP) during the first decades, but the effect was insignificant by the end of the 21st century. The decrease was caused by decreased temperature of the ocean and climate system in general, not by the decrease in available sunlight as might have been expected. This was demonstrated by two sensitivity simulations where geoengineering was affecting only either temperature or the light available to marine ecosystems. The simulation GEO-ALL behaves in a different way than GEO: ocean NPP was lower than that in CTRL for the first three decades of geoengineering as in GEO, but then NPP increased over the level in CTRL for the remaining of the simulation. In

  4. Assessing Land Management Change Effects on Forest Carbon and Emissions Under Changing Climate

    NASA Astrophysics Data System (ADS)

    Law, B. E.

    2014-12-01

    There has been limited focus on fine-scale land management change effects on forest carbon under future environmental conditions (climate, nitrogen deposition, increased atmospheric CO2). Forest management decisions are often made at the landscape to regional levels before analyses have been conducted to determine the potential outcomes and effectiveness of such actions. Scientists need to evaluate plausible land management actions in a timely manner to help shape policy and strategic land management. Issues of interest include species-level adaptation to climate, resilience and vulnerability to mortality within forested landscapes and regions. Efforts are underway to improve land system model simulation of future mortality related to climate, and to develop and evaluate plausible land management options that could help mitigate or avoid future die-offs. Vulnerability to drought-related mortality varies among species and with tree size or age. Predictors of species ability to survive in specific environments are still not resolved. A challenge is limited observations for fine-scale (e.g. 4 km2) modeling, particularly physiological parameters. Uncertainties are primarily associated with future land management and policy decisions. They include the interface with economic factors and with other ecosystem services (biodiversity, water availability, wildlife habitat). The outcomes of future management scenarios should be compared with business-as-usual management under the same environmental conditions to determine the effects of management changes on forest carbon and net emissions to the atmosphere. For example, in the western U.S., land system modeling and life cycle assessment of several management options to reduce impacts of fire reduced long-term forest carbon gain and increased carbon emissions compared with business-as-usual management under future environmental conditions. The enhanced net carbon uptake with climate and reduced fire emissions after thinning

  5. Black carbon emissions in gasoline exhaust and a reduction alternative with a gasoline particulate filter.

    PubMed

    Chan, Tak W; Meloche, Eric; Kubsh, Joseph; Brezny, Rasto

    2014-05-20

    Black carbon (BC) mass and solid particle number emissions were obtained from two pairs of gasoline direct injection (GDI) vehicles and port fuel injection (PFI) vehicles over the U.S. Federal Test Procedure 75 (FTP-75) and US06 Supplemental Federal Test Procedure (US06) drive cycles on gasoline and 10% by volume blended ethanol (E10). BC solid particles were emitted mostly during cold-start from all GDI and PFI vehicles. The reduction in ambient temperature had significant impacts on BC mass and solid particle number emissions, but larger impacts were observed on the PFI vehicles than the GDI vehicles. Over the FTP-75 phase 1 (cold-start) drive cycle, the BC mass emissions from the two GDI vehicles at 0 °F (-18 °C) varied from 57 to 143 mg/mi, which was higher than the emissions at 72 °F (22 °C; 12-29 mg/mi) by a factor of 5. For the two PFI vehicles, the BC mass emissions over the FTP-75 phase 1 drive cycle at 0 °F varied from 111 to 162 mg/mi, higher by a factor of 44-72 when compared to the BC emissions of 2-4 mg/mi at 72 °F. The use of a gasoline particulate filter (GPF) reduced BC emissions from the selected GDI vehicle by 73-88% at various ambient temperatures over the FTP-75 phase 1 drive cycle. The ambient temperature had less of an impact on particle emissions for a warmed-up engine. Over the US06 drive cycle, the GPF reduced BC mass emissions from the GDI vehicle by 59-80% at various temperatures. E10 had limited impact on BC emissions from the selected GDI and PFI vehicles during hot-starts. E10 was found to reduce BC emissions from the GDI vehicle by 15% at standard temperature and by 75% at 19 °F (-7 °C). PMID:24758145

  6. 40 CFR Table U-1 to Subpart U of... - CO2 Emission Factors for Common Carbonates

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 21 2011-07-01 2011-07-01 false CO2 Emission Factors for Common.... 98, Subpt. U, Table U-1 Table U-1 to Subpart U of Part 98—CO2 Emission Factors for Common Carbonates Mineral name—carbonate CO2 emission factor(tons CO2/ton carbonate) Limestone—CaCO3 0.43971...

  7. QCGAT aircraft/engine design for reduced noise and emissions

    NASA Technical Reports Server (NTRS)

    Lanson, L.; Terrill, K. M.

    1980-01-01

    The high bypass ratio QCGAT engine played an important role in shaping the aircraft design. The aircraft which evolved is a sleek, advanced design, six-place aircraft with 3538 kg (7,800 lb) maximum gross weight. It offers a 2778 kilometer (1500 nautical mile) range with cruise speed of 0.5 Mach number and will take-off and land on the vast majority of general aviation airfields. Advanced features include broad application of composite materials and a supercritical wing design with winglets. Full-span fowler flaps were introduced to improve landing capability. Engines are fuselage-mounted with inlets over the wing to provide shielding of fan noise by the wing surfaces. The design objectives, noise, and emission considerations, engine cycle and engine description are discussed as well as specific design features.

  8. Fire-related carbon emissions from land use transitions in southern Amazonia

    NASA Astrophysics Data System (ADS)

    DeFries, R. S.; Morton, D. C.; van der Werf, G. R.; Giglio, L.; Collatz, G. J.; Randerson, J. T.; Houghton, R. A.; Kasibhatla, P. K.; Shimabukuro, Y.

    2008-11-01

    Various land-use transitions in the tropics contribute to atmospheric carbon emissions, including forest conversion for small-scale farming, cattle ranching, and production of commodities such as soya and palm oil. These transitions involve fire as an effective and inexpensive means for clearing. We applied the DECAF (DEforestation CArbon Fluxes) model to Mato Grosso, Brazil to estimate fire emissions from various land-use transitions during 2001-2005. Fires associated with deforestation contributed 67 Tg C/yr (17 and 50 Tg C/yr from conversion to cropland and pasture, respectively), while conversion of savannas and existing cattle pasture to cropland contributed 17 Tg C/yr and pasture maintenance fires 6 Tg C/yr. Large clearings (>100 ha/yr) contributed 67% of emissions but comprised only 10% of deforestation events. From a policy perspective, results imply that intensification of agricultural production on already-cleared land and policies to discourage large clearings would reduce the major sources of emissions from fires in this region.

  9. Greenhouse gas emissions during composting of dairy manure: Delaying pile mixing does not reduce overall emissions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effect of the timing of pile mixing on greenhouse gas (GHG) emissions during dairy manure composting was determined using large flux chambers designed to completely cover replicate pilot-scale compost piles. GHG emissions from compost piles that were mixed at 2, 3, 4, or 5 weeks after initial c...

  10. Synthesis and electron emission properties of aligned carbon nanotube arrays

    NASA Astrophysics Data System (ADS)

    Neupane, Suman

    Carbon nanotubes (CNTs) have become one of the most interesting allotropes of carbon due to their intriguing mechanical, electrical, thermal and optical properties. The synthesis and electron emission properties of CNT arrays have been investigated in this work. Vertically aligned CNTs of different densities were synthesized on copper substrate with catalyst dots patterned by nanosphere lithography. The CNTs synthesized with catalyst dots patterned by spheres of 500 nm diameter exhibited the best electron emission properties with the lowest turn-on/threshold electric fields and the highest field enhancement factor. Furthermore, CNTs were treated with NH3 plasma for various durations and the optimum enhancement was obtained for a plasma treatment of 1.0 min. CNT point emitters were also synthesized on a flat-tip or a sharp-tip to understand the effect of emitter geometry on the electron emission. The experimental results show that electron emission can be enhanced by decreasing the screening effect of the electric field by neighboring CNTs. In another part of the dissertation, vertically aligned CNTs were synthesized on stainless steel (SS) substrates with and without chemical etching or catalyst deposition. The density and length of CNTs were determined by synthesis time. For a prolonged growth time, the catalyst activity terminated and the plasma started etching CNTs destructively. CNTs with uniform diameter and length were synthesized on SS substrates subjected to chemical etching for a period of 40 minutes before the growth. The direct contact of CNTs with stainless steel allowed for the better field emission performance of CNTs synthesized on pristine SS as compared to the CNTs synthesized on Ni/Cr coated SS. Finally, fabrication of large arrays of free-standing vertically aligned CNT/SnO2 core-shell structures was explored by using a simple wet-chemical route. The structure of the SnO2 nanoparticles was studied by X-ray diffraction and electron microscopy

  11. A Systems Approach to Reducing Institutional GHG Emissions

    ERIC Educational Resources Information Center

    Williamson, Sean R.

    2012-01-01

    Purpose: The purpose of this paper is to establish necessity and methods for considering greenhouse gas (GHG) mitigation policies at a system-level. The research emphasizes connecting narrowly focused GHG mitigation objectives (e.g. reduce single occupancy vehicle travel) with broader institutional objectives (e.g. growth in student population) to…

  12. The environmental cost of reducing agricultural fine particulate matter emissions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The US Environmental Protection Agency (EPA) revised the National Ambient Air Quality Standards (NAAQS) in 2006, reducing acceptable fine particulate (PM2.5) levels; state environmental protection agencies in states with non-attainment areas are required to draft State Implementation Plans (SIP) det...

  13. The Effect of the Hayward Corridor Improvement Project on Carbon Monoxide Emission

    NASA Astrophysics Data System (ADS)

    Muhlfelder, M.; Martinez, E.; Maestas, A.; Peek, A.

    2013-12-01

    In August of 2010, construction began on a stretch of road in Downtown Hayward to address a problem with traffic flow. Known as the Hayward Corridor, the project reshaped the flow of traffic, replacing the two way streets of Foothill, Mission, and A Street with a loop between them. This project began with the initiative of reducing congestion in this area and improving access to businesses for pedestrians. The project was expected to have little environmental impact in most common assessments of degree of effect, including particulate matter, ozone and carbon monoxide levels. This report will discuss the effect of the Hayward Corridor Improvement Project on carbon monoxide emission. Data available to the public in the project's Environmental Impact Report shows that carbon monoxide levels before construction began were at an acceptable level according to federal and state standards. Projections for future concentrations both with and without the project show a decrease in carbon monoxide levels due to technological improvements and the gradual replacement of older, less efficient vehicles. The Environmental Impact Report projected that there would be little difference in carbon monoxide levels whether the project took place or not, at an average of 1.67x102 fewer parts per million per 1 hour period of measurement emitted in the case of the project not taking place. While it is not possible to draw a conclusion on what the current carbon monoxide levels would be if the project had not taken place due to the changes in traffic flow and other surrounding roads as a result of the project, the data gathered in June of 2013 suggested that carbon monoxide levels are higher than the values projected in 2007. This report summarizes both the accuracy of these carbon monoxide level projections and the effect of construction on carbon monoxide levels in the Hayward Corridor and the surrounding area.

  14. Carbon dioxide emissions from estuaries of northern and northeastern Brazil

    PubMed Central

    Noriega, Carlos; Araujo, Moacyr

    2014-01-01

    The carbon dioxide flux through the air–water interface of coastal estuarine systems must be quantified to understand the regional balance of carbon and its transport through adjacent coastal regions. We estimated and calculated the emissions of carbon dioxide (FCO2) and the partial pressure of CO2 (pCO2) values in 28 estuarine environments at a variety of spatial scales in the northern and northeastern regions of Brazil. The results showed a mean FCO2 (water to air) of 55 ± 45 mmol·m−2·d−1. Additionally, a negative correlation between dissolved oxygen saturation and pCO2 was observed, indicating a control by biological processes and especially by organic matter degradation. This leads to increased dissolved CO2 concentration in estuarine waters which results in a pCO2 that reached 8,638 μatm. Our study suggests that northern and northeastern Brazilian estuaries act as sources of atmospheric CO2. The range of pCO2 observed were similar to those found in inner estuaries in other places around the world, with the exception of a few semi-arid estuaries (Köppen climate classification – BSh) in which record low levels of pCO2 have been detected. PMID:25145418

  15. Carbon emissions from deforestation in the Brazilian Amazon Region

    NASA Astrophysics Data System (ADS)

    Potter, C.; Klooster, S.; Genovese, V.

    2009-11-01

    A simulation model based on satellite observations of monthly vegetation greenness from the Moderate Resolution Imaging Spectroradiometer (MODIS) was used to estimate monthly carbon fluxes in terrestrial ecosystems of Brazilian Amazon and Cerrado regions over the period 2000-2002. The NASA-CASA (Carnegie Ames Stanford Approach) model estimates of annual forest production were used for the first time as the basis to generate a prediction for the standing pool of carbon in above-ground biomass (AGB; g C m-2) for forested areas of the Brazilian Amazon region. Plot-level measurements of the residence time of carbon in wood in Amazon forest from Malhi et al. (2006) were interpolated by inverse distance weighting algorithms and used with CASA to generate a new regional map of AGB. Data from the Brazilian PRODES (Estimativa do Desflorestamento da Amazônia) project were used to map deforested areas. Results show that net primary production (NPP) sinks for carbon varied between 4.25 Pg C yr-1 (1 Pg{=}1015 g) and 4.34 Pg C for the region and were highest across the eastern and northern Amazon areas, whereas deforestation sources of CO2 flux from decomposition of residual woody debris were higher and less seasonal in the central Amazon than in the eastern and southern areas. Increased woody debris from past deforestation events was predicted to alter the net ecosystem carbon balance of the Amazon region to generate annual CO2 source fluxes at least two times higher than previously predicted by CASA modeling studies. Variations in climate, land cover, and forest burning were predicted to release carbon at rates of 0.5 to 1 Pg C yr-1 from the Brazilian Amazon. When direct deforestation emissions of CO2 from forest burning of between 0.2 and 0.6 Pg C yr-1 in the Legal Amazon are overlooked in regional budgets, the year-to-year variations in this net biome flux may appear to be large, whereas our model results implies net biome fluxes had actually been relatively consistent from

  16. Carbon Emissions from Deforestation in the Brazilian Amazon Region

    NASA Technical Reports Server (NTRS)

    Potter, C.; Klooster, S.; Genovese, V.

    2009-01-01

    A simulation model based on satellite observations of monthly vegetation greenness from the Moderate Resolution Imaging Spectroradiometer (MODIS) was used to estimate monthly carbon fluxes in terrestrial ecosystems of Brazilian Amazon and Cerrado regions over the period 2000-2002. The NASA-CASA (Carnegie Ames Stanford Approach) model estimates of annual forest production were used for the first time as the basis to generate a prediction for the standing pool of carbon in above-ground biomass (AGB; gC/sq m) for forested areas of the Brazilian Amazon region. Plot-level measurements of the residence time of carbon in wood in Amazon forest from Malhi et al. (2006) were interpolated by inverse distance weighting algorithms and used with CASA to generate a new regional map of AGB. Data from the Brazilian PRODES (Estimativa do Desflorestamento da Amazonia) project were used to map deforested areas. Results show that net primary production (NPP) sinks for carbon varied between 4.25 Pg C/yr (1 Pg=10(exp 15)g) and 4.34 Pg C for the region and were highest across the eastern and northern Amazon areas, whereas deforestation sources of CO2 flux from decomposition of residual woody debris were higher and less seasonal in the central Amazon than in the eastern and southern areas. Increased woody debris from past deforestation events was predicted to alter the net ecosystem carbon balance of the Amazon region to generate annual CO2 source fluxes at least two times higher than previously predicted by CASA modeling studies. Variations in climate, land cover, and forest burning were predicted to release carbon at rates of 0.5 to 1 Pg C/yr from the Brazilian Amazon. When direct deforestation emissions of CO2 from forest burning of between 0.2 and 0.6 Pg C/yr in the Legal Amazon are overlooked in regional budgets, the year-to-year variations in this net biome flux may appear to be large, whereas our model results implies net biome fluxes had actually been relatively consistent from

  17. Direct green waste land application: How to reduce its impacts on greenhouse gas and volatile organic compound emissions?

    PubMed

    Zhu-Barker, Xia; Burger, Martin; Horwath, William R; Green, Peter G

    2016-06-01

    Direct land application as an alternative to green waste (GW) disposal in landfills or composting requires an understanding of its impacts on greenhouse gas (GHG) and volatile organic compound (VOC) emissions. We investigated the effects of two approaches of GW direct land application, surface application and soil incorporation, on carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4), and VOC emissions for a 12month period. Five treatments were applied in fall 2013 on fallow land under a Mediterranean climate in California: 30cm height GW on surface; 15cm height GW on surface; 15cm height GW tilled into soil; control+till; control+no till. In addition, a laboratory experiment was conducted to develop a mechanistic understanding of the influence of GW application on soil O2 consumption and GHG emission. The annual cumulative N2O, CO2 and VOC emissions ranged from 1.6 to 5.5kgN2O-Nha(-1), 5.3 to 40.6MgCO2-Cha(-1) and 0.6 to 9.9kgVOCha(-1), respectively, and were greatly reduced by GW soil incorporation compared to surface application. Application of GW quickly consumed soil O2 within one day in the lab incubation. These results indicate that to reduce GHG and VOC emissions of GW direct land application, GW incorporation into soil is recommended. PMID:27033991

  18. Freshwater greenhouse gas emissions and their implications on landscape level carbon balances in India

    NASA Astrophysics Data System (ADS)

    Panneer Selvam, B.; Natchimuthu, S.; Arunachalam, L.; Bastviken, D.

    2012-04-01

    Methane (CH4) and carbon dioxide (CO2) emissions from global freshwaters are important sources of greenhouse gases to the atmosphere. It has been estimated that about 0.65 Pg of C (CO2 equiv.) yr-1 in the form of CH4 and 1.4 Pg C yr -1 in the form of CO2 is being emitted from global freshwaters. Therefore, including freshwater emissions in the greenhouse gas budgets in the national or global levels could significantly reduce the estimated land carbon sink, but present estimates suffer from lack of data, in particular from tropical freshwaters. Hence, we attempted to test the validity of the land carbon sink estimate in India, a tropical country with a large number of natural and man-made water bodies. We measured the CH4 and CO2 fluxes and surface water concentrations from a wide variety of inland freshwaters like lakes, ponds, rivers, reservoirs, open wells, canals and springs in three South Indian states, Tamil Nadu, Kerala and Andhra Pradesh. We observed that almost all of these freshwater systems emitted varied amounts of CH4 and a majority of them emitted CO2, similar to other tropical locations in South America. We extrapolated the measured fluxes for the whole of Indian inland waters by using the total area of different categories of inland waters in the national wetland atlas of India. By comparing our estimates of aquatic fluxes with the national greenhouse gas budget, we show that the land carbon sink of India is substantially overestimated. Thus, freshwater emissions are important components of greenhouse gas budgets on a landscape level and it is necessary to incorporate them in national and global greenhouse gas budgets to accurately quantify the land carbon sink.

  19. Internal modifications to reduce pollutant emissions from marine engines. A numerical approach

    NASA Astrophysics Data System (ADS)

    Lamas, M. I.; Rodríguez, C. G.; Rodríguez, J. D.; Telmo, J.

    2013-12-01

    Taking into account the increasingly stringent legislation on emissions from marine engines, this work aims to analyze several internal engine modifications to reduce NOx (nitrogen oxides) and other pollutants. To this end, a numerical model was employed to simulate the operation cycle and characterize the exhaust gas composition. After a preliminary validation process was carried out using experimental data from a four-stroke, medium-speed marine engine, the numerical model was employed to study the influence of several internal modifications, such as water addition from 0 to 100% water to fuel ratios, exhaust gas recirculation from 0 to 100% EGR rates, modification of the overlap timing from 60 to 120°, modification of the intake valve closing from 510 to 570°, and modification of the cooling water temperature from 70 to 90 oC. NOx was reduced by nearly 100%. As expected, it was found that, by lowering the combustion temperature, there is a notable reduction in NOx, but an increase in CO (carbon monoxide), HC (hydrocarbons) and consumption.

  20. Evaluation of TIF to reduce fumigant emissions and the potential to use reduced rates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Strawberry growers in California rely heavily on soil fumigation to assure profitable berries and high yields. However, the adverse impact on air quality from fumigant emissions threatens the availability of fumigants for agricultural use. The objective of this research was to determine the performa...

  1. Bioenergy and biobased products hold promise of reducing pollution emissions

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    Trees and other plants have, of course, long been useful for the wood and agricultural benefits they provide. Now, this organic matter is gaining new cachet as “biomass.”Some scientists hope that this stuff can be converted into practically a panacea of goods, including transportation fuels, electricity, commercial products such as chemicals, glues, and paints, and other materials—reducing societal dependence on petrochemical products.

  2. Method and apparatus for reducing solvent luminescence background emissions

    DOEpatents

    Affleck, Rhett L.; Ambrose, W. Patrick; Demas, James N.; Goodwin, Peter M.; Johnson, Mitchell E.; Keller, Richard A.; Petty, Jeffrey T.; Schecker, Jay A.; Wu, Ming

    1998-01-01

    The detectability of luminescent molecules in solution is enhanced by reducing the background luminescence due to impurity species also present in the solution. A light source that illuminates the solution acts to photolyze the impurities so that the impurities do not luminesce in the fluorescence band of the molecule of interest. Molecules of interest may be carried through the photolysis region in the solution or may be introduced into the solution after the photolysis region.

  3. Method and apparatus for reducing solvent luminescence background emissions

    DOEpatents

    Affleck, R.L.; Ambrose, W.P.; Demas, J.N.; Goodwin, P.M.; Johnson, M.E.; Keller, R.A.; Petty, J.T.; Schecker, J.A.; Wu, M.

    1998-10-27

    The detectability of luminescent molecules in solution is enhanced by reducing the background luminescence due to impurity species also present in the solution. A light source that illuminates the solution acts to photolyze the impurities so that the impurities do not luminesce in the fluorescence band of the molecule of interest. Molecules of interest may be carried through the photolysis region in the solution or may be introduced into the solution after the photolysis region. 6 figs.

  4. Chronic restraint stress reduces carbon tetrachloride-induced liver fibrosis

    PubMed Central

    LI, MENG; SUN, QUAN; LI, SHENGLI; ZHAI, YANAN; WANG, JINGJING; CHEN, BAIAN; LU, JING

    2016-01-01

    Stress as a cofactor has been reported to affect the progression and severity of liver diseases. The present study investigated the effect of chronic restraint stress on carbon tetrachloride (CCl4)-induced liver fibrosis. A total of 30 male BALB/c mice were randomly divided into three groups: Oil-treated control group; CCl4-treated group; and CCl4 + restraint-treated group. CCl4 was administrated via intraperitoneal injection once every 3 days over a period of 42 days. In the CCl4 + restraint-treated group, mice were immobilized using 50 ml centrifuge tubes for 0.5 h to inflict chronic restraint stress immediately after the injection of CCl4. On day 42, blood and liver tissue samples were collected for analysis. The effect of restraint on CCl4-induced liver fibrosis in mice was evaluated by analyzing the serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Histopathological examination of liver samples was performed using hematoxylin and eosin (HE), Masson's trichrome, 5-hydroxytryptamine 2B (5-HT2B) receptor and α-smooth muscle actin (α-SMA) immumohistochemical staining. ALT, AST, 5-HT2B receptor and α-SMA expression levels were significantly increased in mice exposed to CCl4 in comparison with those in the oil-treated control mice (P<0.01). However, these increases were significantly reduced by exposure to restraint (P<0.05). HE and Masson's trichrome staining revealed that restraint can alleviate CCl4-induced liver fibrosis. These results suggest that chronic restraint stress reduces the development of liver fibrosis by inhibiting the activation of hepatic stellate cells via 5-HT2B receptor. Therefore, restraint may be a useful therapeutic approach in the management of liver fibrosis. PMID:27284296

  5. Enhancement of field emission properties of cyanoacrylate carbon nanotube arrays by laser treatment

    NASA Astrophysics Data System (ADS)

    Liu, Yuming; Fan, Shou Shan

    2004-08-01

    Cyanoacrylate-carbon nanotube arrays are prepared by embedding carbon nanotube (CNT) arrays grown on silicon substrate in cyanoacrylate adhesive. Upon laser treatment, enhanced field emission properties are obtained. Moreover, the binding force between the carbon nanotubes and the substrate is strengthened by the cyanoacrylate adhesive. When the field emission current is large enough at high electric field, the carbon nanotubes cannot be pulled out of the substrate by electric field force. A large field emission current can be obtained from cyanoacrylate-carbon nanotube arrays at relatively low voltage just by decreasing the distance between the anode and the cathode.

  6. Emissivity of a multibeam electron gun with a glassy carbon field-emission cathode

    NASA Astrophysics Data System (ADS)

    Bushuev, N. A.; Glukhova, O. E.; Grigor'ev, Yu. A.; Ivanov, D. V.; Kolesnikova, A. S.; Nikolaev, A. A.; Shalaev, P. D.; Shesterkin, V. I.

    2016-02-01

    A multibeam triode electron gun with a glassy carbon field-emission cathode that is intended for an O-type microwave amplifier is studied. The electric field strength and the current density at the microtips versus the distance to the center of a cell of the cathode-grid unit are calculated. Calculation data are compared with experimental results. It is shown that about 70% of the cathode current in each cell is accounted for by microtips arranged in a circumferential ring no wider than 20 μm. The field-emission current density inside the ring exceeds 40 A/cm2, and the current per microtip equals 43.1 μA.

  7. Atmospheric impacts of black carbon emission reductions through the strategic use of biodiesel in California.

    PubMed

    Zhang, Hongliang; Magara-Gomez, Kento T; Olson, Michael R; Okuda, Tomoaki; Walz, Kenneth A; Schauer, James J; Kleeman, Michael J

    2015-12-15

    The use of biodiesel as a replacement for petroleum-based diesel fuel has gained interest as a strategy for greenhouse gas emission reductions, energy security, and economic advantage. Biodiesel adoption may also reduce particulate elemental carbon (EC) emissions from conventional diesel engines that are not equipped with after-treatment devices. This study examines the impact of biodiesel blends on EC emissions from a commercial off-road diesel engine and simulates the potential public health benefits and climate benefits. EC emissions from the commercial off-road engine decreased by 76% when ultra-low sulfur commercial diesel (ULSD) fuel was replaced by biodiesel. Model calculations predict that reduced EC emissions translate directly into reduced EC concentrations in the atmosphere, but the concentration of secondary particulate matter was not directly affected by this fuel change. Redistribution of secondary particulate matter components to particles emitted from other sources did change the size distribution and therefore deposition rates of those components. Modification of meteorological variables such as water content and temperature influenced secondary particulate matter formation. Simulations with a source-oriented WRF/Chem model (SOWC) for a severe air pollution episode in California that adopted 75% biodiesel blended with ULSD in all non-road diesel engines reduced surface EC concentrations by up to 50% but changed nitrate and total PM2.5 mass concentrations by less than ±5%. These changes in concentrations will have public health benefits but did not significantly affect radiative forcing at the top of the atmosphere. The removal of EC due to the adoption of biodiesel produced larger coatings of secondary particulate matter on other atmospheric particles containing residual EC leading to enhanced absorption associated with those particles. The net effect was a minor change in atmospheric optical properties despite a large change in atmospheric EC

  8. Evaluation of Refrigerating and Air Conditioning Devices in Energy Cascade Systems under the Restriction of Carbon Dioxide Emissions

    NASA Astrophysics Data System (ADS)

    Shimazaki, Yoichi; Akisawa, Atsushi; Kashiwagi, Takao

    It is necessary to introduce energy cascade systems into the industrial sector in Japan to reduce carbon dioxide emissions. The aim of this study is to evaluate the refrigerating and air conditioning devices in cases of introducing both energy cascade systems and thermal recycling systems in industries located around urban areas. The authors have developed an energy cascade model based on linear programming so as to minimize the total system costs with carbon taxes. Five cases are investigated. Limitation of carbon dioxide emissions results in the enhancement of heat cascading, where high temperature heat is supplied for process heating while low temperature one is shifted to refrigeration. It was found that increasing the amount of garbage combustor waste heat can reduce electric power for the turbo refrigerator by promoting waste heat driven ammonia absorption refrigerator.

  9. Mobile laboratory measurements of black carbon, polycyclic aromatic hydrocarbons and other vehicle emissions in Mexico City

    NASA Astrophysics Data System (ADS)

    Jiang, M.; Marr, L. C.; Dunlea, E. J.; Herndon, S. C.; Jayne, J. T.; Kolb, C. E.; Knighton, W. B.; Rogers, T. M.; Zavala, M.; Molina, L. T.; Molina, M. J.

    2005-08-01

    Black carbon (BC) and polycyclic aromatic hydrocarbons (PAHs) are of concern due to their effects on climate and health. The main goal of this research is to provide the first estimate of emissions of BC and particle-phase PAHs (PPAHs) from motor vehicles in Mexico City. The emissions of other pollutants including carbon monoxide (CO), oxides of nitrogen (NOx), volatile organic compounds (VOCs), and particulate matter of diameter 2.5 µm and less (PM2.5) are also estimated. As a part of the Mexico City Metropolitan Area field campaign in April 2003 (MCMA-2003), a mobile laboratory was driven throughout the city. The laboratory was equipped with a comprehensive suite of gas and particle analyzers, including an aethalometer that measured BC and a photoionization aerosol sensor that measured PPAHs. While driving through traffic, the mobile lab is continuously sampling exhaust plumes from the vehicles around it. We have developed a method of automatically identifying exhaust plumes, which are then used as the basis for calculation of fleet-average emission factors. In the approximately 75 h of on-road sampling during the field campaign, we have identified ~30 000 exhaust measurement points that represent a variety of vehicle types and driving conditions. The large sample provides a basis for estimating fleet-average emission factors and thus the emission inventory. Motor vehicles in the Mexico City area are estimated to emit 1700±200 metric tons BC, 57±6 tons PPAHs, 1 190 000±40 000 tons CO, 120 000±3000 tons NOx, 202 000±4000 tons VOCs, and 4400±400 tons PM2.5 per year, not including cold start emissions. The estimates for CO, NOx, and PPAHs may be low by up to 10% due to the slower response time of analyzers used to measure these species. Compared to the government's official motor vehicle emission inventory for the year 2002, the estimates for CO, NOx, VOCs, and PM2.5 are 38% lower, 23% lower, 7% higher, and 26% higher, respectively. The distributions of

  10. Brown carbon in fresh and aged biomass burning emissions

    NASA Astrophysics Data System (ADS)

    Saleh, R.; Robinson, E.; Tkacik, D. S.; Ahern, A.; Liu, S.; Aiken, A. C.; Sullivan, R. C.; Presto, A. A.; Dubey, M.; Donahue, N. M.; Robinson, A. L.

    2013-12-01

    To date, most climate forcing calculations treat black carbon (BC) and dust as the only particulate light absorbers. Numerous studies have shown that some organic aerosols (OA), referred to as brown carbon (BrC), also absorb light. BrC has been identified in biomass burning emissions; however, its light absorption properties are poorly constrained. Literature values of the imaginary part of the refractive indices of biomass burning OA (kOA) span two orders of magnitude. This variability, attributed to differences in fuel type and burning conditions, complicates the representation of biomass burning BrC in climate models. Proper accounting for BrC absorption in climate forcing calculations is of great importance. It can enhance the models' performance, bringing estimates of climate sensitivity to better agreement with observations. Here, we investigate the source of variability in absorptivity of biomass-burning OA observed in this study. We show that absorptivity is closely linked to OA volatility. Specifically, low-volatility organic compounds (LVOCs) are responsible for most of the light absorption, with effective kOA 1-2 orders of magnitude greater than the semi-volatile organic compounds (SVOCs). The effective kOA of biomass-burning emissions thus depends on the extent to which SVOCs partition to the condensed phase, which is sensitive to OA loading. kOA increases by a factor of 3-4 when the emissions are diluted from source concentrations (1-10 mg/m3) to atmospheric-like concentrations (1-10 μg/m3), as the partitioning of SVOCs shifts towards the gas phase. More importantly, we demonstrate that the effective kOA depends largely on burn conditions, and not fuel type. Burns which produce high levels of BC emit OA that is more absorptive than burns which produce low levels of BC. The dependence of kOA on OA loading and burn conditions can be parameterized as a function of a single property of the emissions, namely the BC-to-OA ratio. Specifically, kOA at

  11. Woody encroachment reduces nutrient limitation and promotes soil carbon sequestration

    PubMed Central

    Blaser, Wilma J; Shanungu, Griffin K; Edwards, Peter J; Olde Venterink, Harry

    2014-01-01

    During the past century, the biomass of woody species has increased in many grassland and savanna ecosystems. As many of these species fix nitrogen symbiotically, they may alter not only soil nitrogen (N) conditions but also those of phosphorus (P). We studied the N-fixing shrub Dichrostachys cinerea in a mesic savanna in Zambia, quantifying its effects upon pools of soil N, P, and carbon (C), and availabilities of N and P. We also evaluated whether these effects induced feedbacks upon the growth of understory vegetation and encroaching shrubs. Dichrostachys cinerea shrubs increased total N and P pools, as well as resin-adsorbed N and soil extractable P in the top 10-cm soil. Shrubs and understory grasses differed in their foliar N and P concentrations along gradients of increasing encroachment, suggesting that they obtained these nutrients in different ways. Thus, grasses probably obtained them mainly from the surface upper soil layers, whereas the shrubs may acquire N through symbiotic fixation and probably obtain some of their P from deeper soil layers. The storage of soil C increased significantly under D. cinerea and was apparently not limited by shortages of either N or P. We conclude that the shrub D. cinerea does not create a negative feedback loop by inducing P-limiting conditions, probably because it can obtain P from deeper soil layers. Furthermore, C sequestration is not limited by a shortage of N, so that mesic savanna encroached by this species could represent a C sink for several decades. We studied the effects of woody encroachment on soil N, P, and C pools, and availabilities of N and P to Dichrostachys cinerea shrubs and to the understory vegetation. Both N and P pools in the soil increased along gradients of shrub age and cover, suggesting that N fixation by D. cinerea did not reduce the P supply. This in turn suggests that continued growth and carbon sequestration in this mesic savanna ecosystems are unlikely to be constrained by nutrient

  12. SunShot solar power reduces costs and uncertainty in future low-carbon electricity systems.

    PubMed

    Mileva, Ana; Nelson, James H; Johnston, Josiah; Kammen, Daniel M

    2013-08-20

    The United States Department of Energy's SunShot Initiative has set cost-reduction targets of $1/watt for central-station solar technologies. We use SWITCH, a high-resolution electricity system planning model, to study the implications of achieving these targets for technology deployment and electricity costs in western North America, focusing on scenarios limiting carbon emissions to 80% below 1990 levels by 2050. We find that achieving the SunShot target for solar photovoltaics would allow this technology to provide more than a third of electric power in the region, displacing natural gas in the medium term and reducing the need for nuclear and carbon capture and sequestration (CCS) technologies, which face technological and cost uncertainties, by 2050. We demonstrate that a diverse portfolio of technological options can help integrate high levels of solar generation successfully and cost-effectively. The deployment of GW-scale storage plays a central role in facilitating solar deployment and the availability of flexible loads could increase the solar penetration level further. In the scenarios investigated, achieving the SunShot target can substantially mitigate the cost of implementing a carbon cap, decreasing power costs by up to 14% and saving up to $20 billion ($2010) annually by 2050 relative to scenarios with Reference solar costs. PMID:23865424

  13. THE 217.5 nm BAND, INFRARED ABSORPTION, AND INFRARED EMISSION FEATURES IN HYDROGENATED AMORPHOUS CARBON NANOPARTICLES

    SciTech Connect

    Duley, W. W.; Hu, Anming E-mail: a2hu@uwaterloo.ca

    2012-12-20

    We report on the preparation of hydrogenated amorphous carbon nanoparticles whose spectral characteristics include an absorption band at 217.5 nm with the profile and characteristics of the interstellar 217.5 nm feature. Vibrational spectra of these particles also contain the features commonly observed in absorption and emission from dust in the diffuse interstellar medium. These materials are produced under ''slow'' deposition conditions by minimizing the flux of incident carbon atoms and by reducing surface mobility. The initial chemistry leads to the formation of carbon chains, together with a limited range of small aromatic ring molecules, and eventually results in carbon nanoparticles having an sp {sup 2}/sp {sup 3} ratio Almost-Equal-To 0.4. Spectroscopic analysis of particle composition indicates that naphthalene and naphthalene derivatives are important constituents of this material. We suggest that carbon nanoparticles with similar composition are responsible for the appearance of the interstellar 217.5 nm band and outline how these particles can form in situ under diffuse cloud conditions by deposition of carbon on the surface of silicate grains. Spectral data from carbon nanoparticles formed under these conditions accurately reproduce IR emission spectra from a number of Galactic sources. We provide the first detailed fits to observational spectra of Type A and B emission sources based entirely on measured spectra of a carbonaceous material that can be produced in the laboratory.

  14. The Elephant in the Room: Dealing with Carbon Emissions from Synthetic Transportation Fuels Production

    SciTech Connect

    Parker, Graham B.; Dahowski, Robert T.

    2007-07-11

    Carbon dioxide (CO2), produced by conversion of hydrocarbons to energy, primarily via fossil fuel combustion, is one of the most ubiquitous and significant greenhouse gases (GHGs). Concerns over climate change precipitated by rising atmospheric GHG concentrations have prompted many industrialized nations to begin adopting limits on emissions to inhibit increases in atmospheric CO2 levels. The United Nations Framework Convention on Climate Change states as a key goal the stabilization of atmospheric CO2 at a level that prevents “dangerous anthropogenic interference” with the planet’s climate systems. This will require sharply reducing emissions growth rates in developing nations, and reducing CO2 emissions in the industrialized world to half current rates in the next 50 years. And ultimately, stabilization will require that annual emissions drop to almost zero.Recently, there has been interest in producing synthetic transportation fuels via coal-to-liquids (CTL) production, particularly in countries where there is an abundant supply of domestic coal, including the United States. This paper provides an overview of the current state of CTL technologies and deployment, a discussion of costs and technical requirements for mitigating the CO2 impacts associated with a CTL facility, and the challenges facing the CTL industry as