Failing to curb the impact of climate change could damage the global economy on the scale of the Great Depression or either world war, according to a report issued today by the British government. The environmental devastation could cost between 5 and 20 percent of the world's gross domestic product, the report found.

The report by Nicholas Stern, who heads Britain's Government Economic Service, calls for a new round of international collaboration to cut greenhouse gas emissions linked to global warming.

However, some economic experts questioned the British study's projections, noting that other analyses suggest developed countries will only suffer a modest economic hit.

"There's just a very small part of GDP [in industrialized nations] that's affected by weather in a direct or indirect way," said Jerry Taylor, a senior fellow at the libertarian Cato Institute, which accepts contributions from fossil-fuel companies. "It's very difficult to sketch out this disaster scenario."

The issue of how to approach global warming has been a sticking point between the United States and some of its European allies since the Bush administration disavowed the Kyoto Protocol in 2001, saying it opposed requiring limits on carbon dioxide produced by burning fossil fuels.