CORVALLIS, Ore. -- New research has found that the massive amounts of atmospheric carbon dioxide generated by fossil fuel use in the United States are not completely "offset" by the storage of carbon in growing forests and other vegetation of North America, as some earlier studies had suggested.

The new study, which will be published Friday in the journal Science, may have important implications for the role of the United States in combating the greenhouse effect and global warming.

"Some have argued that the U.S. does not need to reduce greenhouse gas emissions because we're not part of the problem," said Ronald Neilson, a professor of botany at Oregon State University and bioclimatologist with the USDA Forest Service. "Based on this study, we can no longer make that claim." Neilson was a co-author on this research with scientists from the Max-Planck-Institute for Biogeochemistry in Germany, the Ecosystems Center at Woods Hole, Mass., the National Center for Atmospheric Research in Boulder, Colo., and other universities and agencies.

This debate and controversy, Neilson said, is a complicated but important part of the challenge facing nations around the world as they try to decide what to do about global warming and what responsibilities various countries should have. It's also a detective story of researchers looking for the "missing sink" of carbon. More carbon, they say, is being injected into the atmosphere by industrialized nations than can be clearly accounted for in the Earth's atmosphere, land, vegetation and oceans.

"Some past studies suggested that a big part of the missing carbon sink was in the forests and changing land use practices of North America," Neilson said. Increasing levels of atmospheric carbon dioxide can literally "fertilize" plants and trees, researchers say, causing them to grow faster. Also, the United States in particular is converting a large amount of former agricultural land back into forests, which also tends to s
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Contact: Ronald Neilson
neilson@fsl.orst.edu
541-750-7303
Oregon State University
15-Mar-2000