LONDON -- A major British study issued yesterday concludes that rapid and substantial spending to combat global warming is needed to avert a catastrophic reduction in worldwide productivity on the scale of the Great Depression that could devastate food sources, cause widespread deaths and turn hundreds of millions of people into refugees.
The report commissioned by the British government, which officials said was the most comprehensive review ever of the economics of climate change, warns that failure to act could cost the world up to 20 percent a year in lost income. Acting now, however, could bring about meaningful controls in greenhouse gases at a cost of 1 percent of global annual gross domestic product, the report says.
The findings appear to counter the argument of the Bush administration that controls on greenhouse gas emission are costly and possibly ineffective at combating global climate change. At the same time, the projected savings occur only with the kind of rapid and comprehensive international cooperation on the issue that has proved elusive.
British officials said they would take immediate action to legislate carbon reduction targets, push for expanded international carbon-trading programs and move Europe toward a goal of reducing carbon emissions 30 percent by 2020 and 60 percent by 2050. Carbon trading allows companies to exceed emission ceilings by buying credits from those who are below emissions targets.
Prime Minister Tony Blair, calling the report by senior government economist Nicholas Stern "a landmark in the struggle against climate change," warned that there is a limit to what Britain alone can do to achieve results.
"Britain is more than playing its part," he said. "But it is 2 percent of worldwide emissions. Close down all of Britain's emissions, and in less than two years, just the growth in China's emissions would wipe out the difference."
At the same time, he said, the report's findings show that "if the science is right, the consequences for our planet are literally disastrous. And this disaster is not set to happen in some science fiction future, many years ahead, but in our lifetime."
In Washington, the National Oceanic and Atmospheric Administration, the lead federal agency on global warming, had no immediate comment on the report. Jana Goldman, a spokesman for NOAA, said agency officials could not react to the report until they had read it.
The current level of greenhouse gases is 54 percent higher than before the Industrial Revolution and could hit double the rate as early as 2035, the report suggests.
Such an increase could result in an average temperature rise of more than 2 degrees Celsius by midcentury and 5 degrees by century's end, it says.
The result would be melting glaciers, triggering floods while reducing the snow pack that feeds the water supply, consequences that could threaten a sixth of the world's population.
Kim Murphy writes for the Los Angeles Times.