Global warming threatens more than just poles and tropics
A report expected next month is expected to detail how climate shifts are already disrupting the habitats of many species.
Some of the world's most distinctive and biologically diverse climate regions – from South America's Andes Mountains to southern and eastern Africa and the US Southwest – may be drastically altered by century's end, endangering plant and animal life there, according to a new climate-modeling report issued March 26.Skip to next paragraph
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The researchers built their forecast on data contained in a massive study being published in installments this year by the Intergovernmental Panel on Climate Change. An April 6 report by the IPCC, a follow-up to its first report released last month, is expected to detail how climate shifts caused by global warming are already disrupting the habitats of many species and will drive some to extinction.
While polar regions have been thought to show the earliest, most obvious signs of global warming, the tropics will face challenging changes, the new climate modeling shows. Because tropical regions are used to steady temperatures, even small changes of 3 or 4 degrees F. could have a stronger impact than, say, a 5- to 8-degree F. change farther from the equator, according to authors John Williams and John Kutzback, both at the University of Wisconsin, and Stephen Jackson at the University of Wyoming. Their findings appear in the online edition of the Proceedings of the National Academy of Sciences.
"Disappearing climates are primarily concentrated in tropical mountains and the poleward sides of continents....
"Many current species [will be] disrupted or disappear entirely."
It's possible that some species could benefit from climate change, Dr. Williams said in a story by The Associated Press. "But we can't make a prediction, because it's outside our current experience and outside the experience of these species."
Williams played down possible beneficial effects of the change, when interviewed by the Milwaukee Journal Sentinel. From "an ecological perspective, with disappearing climates, there is no real way to put a positive spin on it," he said.
The researchers concluded that if greenhouse-gas emissions keep rising at current rates as much as 39 percent of Earth's land surface could evolve new climates, especially in the tropics, as warmer temperatures spread toward the poles, reported an article in Scientific American online. Earlier studies, the article says, estimate that species such as butterflies are migrating toward the poles at a rate of about 4 miles per decade as temperatures rise.