 2 Feb 2007 @ 14:12, by Unknown
IPCC scientists now say that it is "very likely" that global warming is chiefly driven by the buildup of carbon dioxide (CO2) and other greenhouse gases caused by human activity, and that dangerous levels of warming and sea rise are on the way.
Those two words — the product of 2,500 scientists, 130 nations and 6 years of work — translates into a certainty of over 90%, up from the 66 to 90% chance the panel reported in its last major climate change assessment in 2001. That might not seem like a big difference, but in science, especially in a field as rapidly developing as climate studies, 90% is as good as it gets. The new report effectively completes a scientific revolution that began at the end of the 19th century, when a Swedish geochemist named Svante Arrhenius first proposed that CO2 released into the atmosphere by burning fossil fuels could change the planet's climate.
"The message of this report is that the time for sitting on the fence is finished," says Robert Watson, chief scientist at the World Bank and a former chair of the IPCC. "Now is the time for action."
Perhaps the scariest thing about the IPCC report is that is, by the nature of its composition, probably conservative. The final review, which took place this week in Paris, is painstakingly bureaucratic; the IPCC received 30,000 comments from scientists around the world as the report evolved through numerous drafts. Only the most-solidly backed facts — and often the least-controversial ones — survived the winnowing process. Many scientists had argued during the editing process that the report should say it is "virtually certain" that human activities are causing global warming. That would indicate a 99% certainty. But the change was strongly resisted by China, among other nations, because of its reliance on fossil fuels to help build its economy.
Source:
Bryan Walsh for the Time
and
Thomas H. Maugh II, Times Staff Writer
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