The disastrous hurricanes of recent years have become the poster children of global warming.
But Roger A. Pielke Jr., an environmental policy expert at the University of Colorado at Boulder, wondered whether the billions of dollars of damage was caused by more intense storms or more coastal development.
After analyzing decades of hurricane data, Pielke concluded that rising levels of carbon dioxide had little to do with hurricane damage. Rather, it boiled down to a simple equation: Build more, lose more.
"Everything has been put on the back of carbon dioxide, and carbon dioxide cannot carry that weight," he said.
Pielke's analysis, published last month in the journal Natural Hazards Review, is part of a controversial movement that argues global warming over the rest of this century will play a much smaller role in unleashing planetary havoc than most scientists think.
His research has led him to believe that it is cheaper and more effective to adapt to global warming than to fight it.
Instead of spending trillions of dollars to stabilize carbon dioxide levels across the planet -- an enormously complex and expensive proposition -- the world could work on reducing hunger, storm damage and disease now, thereby neutralizing some of the most feared future problems of global warming.
Hans von Storch, director of the Institute of Coastal Research in Germany, said that the world's problems were already so big that the added burdens caused by rising temperatures would be relatively small. It would be like going 160 kilometers per hour on the autobahn when "going 150 . . . is already dangerous," he said.
Consider a United Nations estimate that global warming would increase the number of people at risk of hunger from 777 million in 2020 to 885 million by 2080, a 14% rise, if current development patterns continue.
That increase could be counteracted by spending on better irrigation systems, drought-resistant crops and more-efficient food transport systems, said Mike Hulme, founding director of the Tyndall Centre for Climate Change Research at the University of East Anglia in England.
"If you're really concerned about drought, those are much more effective strategies than trying to bring down greenhouse gas concentrations," he said.
Downplaying the importance of emissions reductions has raised hackles among scientists around the world, who say that the planet-wide effects of global warming will eventually go beyond humans' ability to deal with it.
"You can't adapt to melting the Greenland ice sheet," said Stephen H. Schneider, a climatologist at Stanford University. "You can't adapt to species that have gone extinct."
Other scientists say that time is running out to control carbon dioxide emissions and that the call to adapt is providing a potentially dangerous excuse to delay. If adaptation were so simple, they say, it would have already been done. But the developing world remains wrought with hunger and disease and vulnerable to natural disasters.
Pielke acknowledges that there are enormous political hurdles to overcome with his strategy, and he recognizes that his views have made him and like-minded researchers the new pariahs of global warming.
"I've been accused of taking money from Exxon or being a right-wing hack," he said.
But unlike those who argue that humans are not warming the globe, the new skeptics accept the scientific consensus on the causes and effects of climate change. Their differences are over what to do about it.
"The radical middle -- that's how we talk about ourselves," said Daniel Sarewitz, a public policy expert at Arizona State University who has collaborated with Pielke on climate policy studies.
Pielke, whose career has focused on the politics of science, likes to describe the scattered collection of scientists and policy wonks as the "non-skeptic heretic club."
The science of global warming was laid out in a series of reports last year by the U.N. Intergovernmental Panel on Climate Change, which shared the Nobel Peace Prize with former Vice President Al Gore. The reports said that temperatures were likely to climb 3 to 8 degrees Fahrenheit by century's end if emissions continued to grow.
They detailed a likely future of worsening famine in Africa, expanding floods as sea levels rise as much as 23 inches, and accelerated species extinction. To avoid the worst, the reports warned that emissions must be reduced 50% to 80% by mid-century, keeping temperature rise below 2 degrees.
The cost, according to the U.N. panel, would amount to as much as 3% of world gross domestic product over the next 20 years, or more than $20 trillion.
The heretics support emissions cuts too, but warn that they have been oversold as a solution to coming catastrophe.
Exhibit A is hurricanes.
The spate of recent storms, particularly Hurricane Katrina in 2005, has come to be seen as a harbinger of a warmer world -- a view popularized by Gore's 2006 documentary, "An Inconvenient Truth."