Monday, May 17, 2004

Global warming's sooty smokescreen revealed

Smoke is clouding our view of global warming, protecting the planet from perhaps three-quarters of the greenhouse effect. That might sound like good news, but experts say that as the cover diminishes in coming decades, we are in for a dramatic escalation of warming that could be two or even three times as great as official best guesses.

This was the dramatic conclusion reached last week at a workshop in Dahlem, Berlin, where top atmospheric scientists got together, including Nobel laureate Paul Crutzen and Swedish meteorologist Bert Bolin, former chairman of the UN's Intergovernmental Panel on Climate Change (IPCC).

IPCC scientists have suspected for a decade that aerosols of smoke and other particles from burning rainforest, crop waste and fossil fuels are blocking sunlight and counteracting the warming effect of carbon dioxide emissions. Until now, they reckoned that aerosols reduced greenhouse warming by perhaps a quarter, cutting increases by 0.2 °C. So the 0.6 °C of warming over the past century would have been 0.8 °C without aerosols.

But the Berlin workshop concluded that...(Full Story)

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