President Obama is expected to commit the United States to achieving a major reduction in greenhouse gases when he attends the climate summit in Copenhagen Dec. 9. Many world leaders are expected to attend the conference, which runs from Dec. 7-18.

Several Duke University experts are available to provide comment and background information on the conference and climate change issues.

Bill Chameides, dean of the Nicholas School of the Environment, is an expert on global climate change and policy options to address it. An atmospheric chemist by training, he blogs (www.thegreengrok.com) regularly on environmental issues, including a six-part series of posts on greenhouse gas emissions cap-and-trade programs and the American Clean Energy and Security Act. (919) 613-8004; bill.chameides@duke.edu.

James Clark, H.L. Blomquist Professor of Environmental Science and Biology, studies the effects of atmospheric chemistry and climate change on forests. He has launched a research program that uses wireless sensor networks and remote sensing to understand the effects of global change on forest ecosystems. (919) 613-8036; jimclark@duke.edu.

Robert B. Jackson, Nicholas Professor of Global Environmental Change, studies feedbacks between people and the biosphere, including studies of the global carbon and water cycles, biosphere/atmosphere interactions, and global change. His recent studies have included lifecycle analysis of corn ethanol and other biofuels to assess their full environmental and economic impacts. (919) 660-7408; jackson@duke.edu.

Susan Lozier, professor of physical oceanography, studies the ocean's response to climate change and elevated carbon dioxide levels. In a study published in Nature in May 2009, she and co-author Amy Bower of Woods Hole Oceanographic Institution reported finding a surprising new pathway for the North Atlantic Ocean circulation, a conveyor belt-like current that helps regulate the Earth's climate. Lozier and Bower's finding may impact the work of global warming forecasters. (919) 681-8199; s.lozier@duke.edu.

Brian Murray, who will be attending the summit, is director for economic analysis at the Nicholas Institute for Environmental Policy Solutions and an expert on the economics of climate-change mitigation in agriculture, forests and land-use patterns. He has co-written a series of policy briefs -- http://www.nicholas.duke.edu/institute/offsetseries.html -- that explain the pros and cons of using agricultural, forest and land-use offsets to incorporate outside-the-cap greenhouse gas mitigation.; bcmurray@duke.edu.

Tim Profeta, who also will be attending the summit, is the director of the Nicholas Institute for Environmental Policy Solutions. He specializes in environmental law, policy and politics, and has been closely following the progress of climate legislation in Congress. Prior coming to Duke in 2005, he served as counsel for the environment to Sen. Joseph Lieberman; in that role, he was a principal architect of the Lieberman-McCain Climate Stewardship Act of 2003. tim.profeta@duke.edu.