Policymakers need to address the influence of global deforestation and urbanization, in addition to that of greenhouse gas emissions, on climate change, asserts Brian Stone, a Georgia Institute of Technology city and regional planning professor, in a paper in the December edition of the journal "Environmental Science and Technology."

As the international community meets in Copenhagen to develop a new framework for responding to climate change, world leaders need to give serious consideration to broadening the range of strategies beyond greenhouse gas reductions alone, Stone argues.

"Across the U.S. as a whole, approximately 50 percent of the warming that has occurred since 1950 is due to land use changes (usually in the form of clearing forest for crops or cities) rather than to the emission of greenhouse gases," Stone says. "Most large U.S. cities, including Atlanta, are warming at more than twice the rate of the planet as a whole—a rate that is mostly attributable to land use change. As a result, emissions reduction programs—like the cap-and-trade program under consideration by the U.S. Congress—may not sufficiently slow climate change in large cities where most people live and where land-use change is the dominant driver of warming."

Stone says his research suggests that slowing the rate of forest loss around the world, and regenerating forests where lost, could slow the pace of global warming significantly.

"Treaty negotiators should formally recognize land-use change as a key driver of warming," says Stone. "The role of land use in global warming is the most important climate-related story that has not been widely covered in the media."

Stone recommends slowing what he terms the "green loss effect" through the planting of millions of trees in urbanized areas and through the protection and regeneration of global forests outside of urbanized regions. Forested areas cool the atmosphere and absorb greenhouse gases. Green architecture, including green roofs and reflective construction materials, would contribute to a slowing of warming rates. Stone envisions local and state governments taking the lead in addressing the land-use drivers of climate change, while the federal government takes the lead in implementing carbon-reduction initiatives.