In the shadow of melting Alpine glaciers, Professor of Biological Oceanography James J. McCarthy spent 10 days in Geneva hammering out a landmark statement of the dangers that humans face due to global climate change.

McCarthy has played a crucial role in helping translate the increasingly complicated scientific research on climate change for policymakers and other non-scientists.

The sole chair of the 100-nation meeting, McCarthy spent nearly every waking moment for four days listening to objections and modifications to a 22-page summary for policymakers that warns of more extreme weather, more serious outbreaks of infectious diseases and increasing stress on already poor agricultural areas in parts of the developing world.

After marathon sessions that left him with an average of four hours of sleep per night, McCarthy closed the session with an 8 a.m. to 2:30 a.m. final push.

"It's the most intense interaction I've ever had with a large group of people," he says. "I used to joke that the biggest problem with chairing a meeting is that you can't nod off. Well, in this situation...you had to show at all times that you were fully attentive and respectful."

The report, which made headlines and news reports across the world, is based upon the scientific work of more than 400 authors and the full report runs to about 1,000 pages.

It cites "shrinkage of glaciers, thawing of permafrost, later freezing and earlier break-up of ice on rivers and lake, and poleward and altitudinal shifts of plant and animal ranges" as evidence of a change in global climate.

The report makes one point very clear: global warming will have devastating effects on developing countries, with serious reverberations for industrialized countries.