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 Now online (1)belb ...and 177 guests Last 5 registered Oplandisks nothingstar N_loop yipe foxtrotromeo Browse members... |
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Scientists Warn of Abrupt World Climate Change By Andrew Quinn SAN FRANCISCO (Reuters) - Global climate change, often seen as a process stretching over thousands of years, could in fact occur abruptly and unexpectedly -- quickly pushing up temperatures by as much as 18 degrees Fahrenheit and wreaking havoc on human society, scientists warned on Wednesday. ``Climate change is not always smooth. Sometimes it is abrupt,'' said Richard Alley, a climate expert at Pennsylvania State University and lead author of a new National Academy of Sciences (news - web sites) report on the threat of rapid climactic shifts. ``If you have a very large, abrupt change, a lot of people and a lot of ecosystems are going to notice,'' he said. ``The bigger and faster it is, the harder it will be to deal with.'' The new National Academy of Sciences report, released this week, warns that gradual global warming coupled with other human impacts on the environment could ``trip the switch'' for sudden climate change. At the American Geophysical Union meeting on Wednesday, Alley and other environmental scientists said the geological evidence indicated that such rapid climate shifts had occurred frequently in the past -- moving temperatures drastically in the space of just a few decades. ``This can happen in less than a human generation, and then it will persist for thousands of years,'' said David Battisti, an atmospheric scientist at the University of Washington. The most immediate dangers posed by abrupt climate change range are devastating droughts and floods which could seriously affect both water supply and agriculture across vast stretches of the planet. Longer term impacts could include changes in the basic systems which determine regional global temperatures. Scientists believe that the Gulf Stream, a current of warm Atlantic water which now keeps much of Northern Europe temperate, could theoretically reverse direction if enough cool fresh water runs into the north Atlantic from melting ice, |
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change that would quickly impact European weather. 'BLINDFOLDED AND WALKING TOWARD A CLIFF' Researchers briefing the AGU meeting said it was clear that the world's oceans play a major role in queuing up rapid climate changes, but that thus far the mechanics of such changes were poorly understood. ``It's like being blindfolded and walking toward the edge of a cliff,'' said Wallace Broeker, a professor of environmental sciences at Columbia University. ``We don't understand (the factors) so we don't really know what to look for.'' Using ice cores drilled from glaciers and other ice sheets, the researchers have developed a model showing world temperatures spiking and dipping with unsettling frequency over the past 110,000 years. While some of the changes have been slow and steady, such as the end of the last Ice Age some 12,000 years ago, others have been swift and unexpected, such as the rapid warming of the North Atlantic from 1920 to 1930 and the Dust Bowl drought of the 1930s. The most drastic temperature changes -- believed to be as much as 18 degrees Fahrenheit over the space of just a few years -- exceed any recorded in human history, they said. Alley said the report was not intended to alarm the public, but that he hoped it would spur policy makers to prepare for the possibility of rapid temperature flux. Greenhouse gases, emitted by fossil fuels such as oil and coal, have been linked by many researchers to a rise in global temperatures. A 1997 Kyoto treaty on global warming sought to cut emissions of such gasses by developed nations, but the Bush administration this year spurned the treaty, saying pollution controls would be too costly for the U.S. economy. The NAS panel called for research to identify what it described as ``no-regrets'' measures that would cost relatively little and would be good policies regardless of the extent of environmental change. Such measures could include regulations to reduce damage to water, air and land, or slow climate cha |
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or slow climate change, or helping societies cope with abrupt climate change by developing new financial instruments such as weather derivatives and catastrophe bonds to reflect the risks, it said. ``Societies have faced both gradual and abrupt climate changes for millennial and have learned to adapt through various mechanisms, such as moving indoors, developing irrigation for crops, and migrating away from inhospitable regions,'' the report said. ``It is important not to be fatalistic about the threats posed by abrupt climate change.'' |
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The earth is over. |
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that's sad, i know... but don't be depressed, because the mankind is over, everything has an end. yup. was the mankind so good that we can be sad. I enjoy everydav till is over.(that reminds me at the baroque time in europe ,-) |
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