The tropics play a major role in global climate dynamics, and are vulnerable to future climate change. We present a record of East African climate since 55 ka, preserved in Lake Malawi sediments, that indicates rapid shifts between discrete climate modes related to abrupt ...

as methane hydrate in the sea floor and permafrost soils and (2) climate-driven changes in methane emissions from northern high-latitude and tropical wetlands. � The size of the methane hydrate reservoir-latitude hydrates and wetlands resulting from increasing Arctic temperatures. � Catastrophic release of methane

The issue of abrupt climate change has been highlighted by a recent National Academy of Sciences (NRC) study as one of the most troubling potential aspects of future global climate change. The science of abrupt climate change originated in the discovery and study of huge ...

Information about the "abrupt climate change" phenomenon characterized by rapid changes in the Earth's climate....

Although abrupt climate changes can occur for many reasons, it is conceivable that human forcing of climate change is increasing the probability of large, abrupt ...

There is a growing body of theoretical and empirical support for the concept of instabilities in the climate system, and indications that abrupt climate change may in some cases contribute to abrupt extinctions. Theoretical indications of instabilities ca...

, but effects were clearly hemispheric to global (4) and included changes in tropical wetlands (23 of global warming often include increased global pre- cipitation, enhanced variability in precipita- tion coolings, with return of salty waters tied to abrupt warmings [e.g. (4)]. Many models of global warming

Models and palaeoclimate data suggest that the tropical Pacific climate system plays a key part in the mechanisms underlying orbital-scale and abrupt climate change. Atmospheric convection over the western tropical Pacific is a major source of heat and moisture to extratropical regions, and may ...

The past decade saw a surge in interest in the role of the Tropics in paleoclimate changes. This was motivated by the emergence of outstanding questions in paleoclimate that pointed to a role for the Tropics in addition to advances in tropical climate dynamics. This article reviews these developments, starting from ...

The role that tropical Pacific ocean/atmospheric variability has had in abrupt climatic changes throughout the Quaternary continues to be debated. The debate centers in part, on how representative modern ocean/atmospheric variability in the tropical Pacific is for characterizing past variability, particularly ...

Climates have sometimes changed abruptly in the past as a result of volcanic eruptions or impacts of huge rocks from space.

The response of tropical forests to climate change will depend on individual plant species' nutritional strategies, which have not been defined in the case of the nitrogen nutrition that is critical to sustaining plant growth and photosynthesis. We used isotope natural abundances to show that a group of tropical plant species with ...

The response of tropical forests to climate change will depend on individual plant species' nutritional strategies, which have not been defined in the case of the nitrogen nutrition that is critical to sustaining plant growth and photosynthesis. We used isotope natural abundances to show that a group of tropical plant species with ...

High-resolution studies of variations in the elemental and stable carbon- and nitrogen-isotope composition of organic matter in cores from Lakes Malawi, Tanganyika, and Bosumtwi (tropical Africa) indicate an abrupt change in the wind-driven circulation of these lakes that, within the limits of available chronologies, was contemporaneous with the end of the ...

Lake sediment core lithostratigraphy, in conjunction with AMS radiocarbon dated macrofossils, geochemistry and palynology, were used to constrain mountain glacier and paleoclimate fluctuations in the Venezuelan Andes during the Late Glacial and Preboreal intervals. Glaciers retreated during an abrupt shift to warmer and wetter conditions at the onset of B�lling warming ...

In order to fully understand abrupt climate events, both high and low-latitude climatic processes must be considered. Here, we examine the carbon isotopic composition of plant leaf wax biomarkers in order to examine changes in C3 versus C4 vegetation, a sensitive indicator of aridity, from the southeastern African ...

... Appendix D - Observed temperature changes on each ... Doug Randall, An Abrupt Climate Change Scenario and ... to A Climate Changed World, (The ...

Information about abrupt climate change research. From the site:"Most of the studies and debates on potential climate change have focused on the ongoing ... ...

The tropical Pacific Ocean plays a central role in the climate system by providing massive fluxes of sensible and latent heat to the atmosphere that have the potential to drive global climate changes. Though some abrupt climate events in the late Pleistocene and Holocene were likely forced ...

Three lines of evidence for abrupt tropical climate change, both past and present, are presented. First, annually and decadally averaged delta(18)O and net mass-balance histories for the last 400 and 2,000 yr, respectively, demonstrate that the current warming at high elevations in the mid- to low latitudes is unprecedented for at ...

Three lines of evidence for abrupt tropical climate change, both past and present, are presented. First, annually and decadally averaged ?¹⁸O and net mass-balance histories for the last 400 and 2,000 yr, respectively, demonstrate that the current warming at high elevations in the mid- to low latitudes is ...

Some 50 years ago, Cesare Emiliani published the first oxygen isotope records from marine sediment cores taken in the Caribbean Sea. He interpreted the observed oscillations as a consequence of 6 deg cooler tropical sea surface temperatures (SSTs) during the Ice Ages. In the following decades, this interpretation was discarded in favor of the dominant role of high latitude ice ...

Major element chemistry and color data from sediment cores in the anoxic Cariaco Basin off Venezuela record with (sub)annual resolution large and abrupt shifts in the hydrologic cycle of the tropical Atlantic during the last 80 ka. These data suggest a direct connection between the position of the ITCZ over northern South America, the strength of trade ...

A network of currents called the Great Ocean Conveyor constantly circulates the water in Earth's oceans and redistributes heat from the tropics toward the poles, keeping some regions far more habitable than they would be otherwise. In this audio segment, scientists discuss the hypothesis that global warming is introducing fresh water into the world's oceans, disrupting the ...

The classical illustration of Holocene climate changes in tropical South America is the huge rising of Titicaca lake level from 4400 to 4000 cal BP. Because the Amazon basin is the source of Andean rainfalls we have explored Amazonian data of climate changes during the Holocene to better understand the cause of this ...

... Title : Two Degrees of Separation: Abrupt Climate Change and the Adverse Impact to US National Security. Descriptive Note : Research paper. ...

Economic and ecological impacts of abrupt climate change This publication is not available online. Please contact a FORT author (see sidebar to right) o...

Today, carrying capacity, which is the ability for the Earth and its natural ... Abrupt climate change is likely to stretch carrying capacity well beyond its already ...

Abrupt Climate Change: Looking at Ocean Currents. A new report supports the hypothesis that heat transfer by ocean currents, rather than global heating or ...

Imperatives for the Next Decade and Beyond Other Related Titles topleft topright Abrupt Climate Change: Inevitable Surprises (2002) Ocean Studies Board (OSB) Polar Research Board...

A variety of proxy palaeoclimatic records from tropical Africa and the adjacent oceans suggest that a climatic event equivalent to the Younger Dryas (YD) also affected this region. To date however, little attention has been directed towards the end of the YD in Africa, even though it has been identified as a period of particularly rapid and profound ...

Tropical climate is dominated on interannual time scales by monsoons and especially by ENSO, which is responsible for meteorological phenomena that directly or indirectly affect most regions on the planet and their populations. Common tropical teleconnections to the extra tropics include a stronger Aleutian low, ...

This study presents evidence for an extended southward migrations of the Intertropical Convergence Zone (ITCZ) in the Southern Hemisphere Pacific region during major climate perturbations of the last 55 kyr. The peat deposits of Lynch's Crater, NE Australia, show several periods with synchronous high ash yield, high Si/Al ratios, high Cyperaceae/Poaceae ratios and heavier ...

Sedimentary time series of color reflectance and major element chemistry from the anoxic Cariaco Basin off the coast of northern Venezuela record large and abrupt shifts in the hydrologic cycle of the tropical Atlantic during the past 90,000 years. Marine productivity maxima and increased precipitation and riverine discharge from northern South America are ...

Abrupt Climate Change NOAA Abrupt Climate Change Climatic Extremes and Weather Events Global Warming and Hurricanes Atlantic Hurricanes and Climate (PDF, 2 pp., 484 kb, About...

Evidence from the Irish Sea basin supports the existence of an abrupt rise in sea level (meltwater pulse) at 19,000 years before the present (B.P.). Climate records indicate a large reduction in the strength of North Atlantic Deep Water formation and attendant cooling of the North Atlantic at this time, indicating a source of the meltwater pulse from one ...

The Cariaco Basin, located off the Venezuelan coast in northern South America, is a sensitive recorder of tropical Atlantic climate variability. For example, analyses of stable carbon isotopic compositions of individual vascular plant leaf waxes preserved in Cariaco Basin sediments have revealed precipitation-driven vegetation shifts during the last ...

Unprecedented global changes of the 20th Century have heightened our awareness of human vulnerability to potential climate changes in the next millennium. Half of the Earth's surface area lies between 30� N and 30� S and supports roughly 70% of the world's population. Thus, variations in the occurrence and intensity of large-scale climate phenomena ...

An abrupt change in the large-scale boreal winter circulation pattern over the North Pacific was observed during the mid-1970s. This paper presents a variety of observed data and model results to describe the climate shift, and to understand some of the links within the coupled climate system that produced, it. Five main findings are ...

Climate factors affecting electrical equipment are characterized for the cold, tropical dry, tropical wet, and tropical marine climates. Categories of electrical equipment are described in design modifications required to function satisfactorily in these ...

The point of these pages is to examine the scientific basis behind abrupt climate change, and evaluate the likelihood of it happening in the future using a question and answer format. Information ranges from a definition of abrupt climate change to the precursor signals that we could monitor now to indicate an ...

modeling and diagnostic proposals focused on understanding the causes of abrupt climate change: � To improve our understanding of the causes of climate variability through modeling and diagnostic studies on multiannual and longer time scales, and � To understand the mechanisms for abrupt ...