Earth's fires fuel global warming.

• Position: Climate Change - Brief article

Fire's potent and pervasive effects on ecosystems and on many Earth processes, including climate change, have been underestimated, according to a report from a team that includes Thomas W. Swetnam, director of the Laboratory of Tree-Ring Research at the University of Arizona, Tucson. "We've estimated that deforestation due to burning by humans is contributing about one-fifth of the human-caused greenhouse effect--and that percentage could become even larger. It's very clear that fire is a primary catalyst of global climate change. This is a call to arms for earth scientists to investigate and better evaluate the role of fire"

All fires combined annually release an amount of carbon dioxide into the atmosphere equal to 50% of that coming from the combustion of fossil fuels. "Fires are obviously one of the major responses to climate change, but fires are not only a response--they feed back to warming, which feeds more fires," Swetnam asserts.

When vegetation burns, the resulting release of stored carbon increases global warming. The more fires, the more...