Monday, July 27, 2009

Climate change increases run-off in eastern US forests

Environment News Service: Computer models of climate change may be underestimating how much water is likely to run off the land and back into the oceans as human activities pump more carbon dioxide and ozone into the atmosphere, a team of NASA-funded researchers concludes.
Runoff may be as much as 17 percent higher in forests of the eastern United States when models also account for changes in soil nitrogen levels and atmospheric ozone exposure. "Failure to consider the effects of nitrogen limitation and ozone on photosynthesis can lead us to underestimate regional runoff," said Benjamin Felzer, an ecosystem modeler at Lehigh University in Bethlehem, Pennsylvania.

…."More runoff could mean more contamination and flooding of our waterways," he said. "It could also mean fewer droughts than predicted for some areas and more water available for human consumption and farming. Either way, water resource managers need more accurate runoff estimates to plan better for the changes."

The team used theoretical models to project various future scenarios for the amount of carbon dioxide in the atmosphere and what it would mean to the changing water cycle in forests east of the Mississippi River. They found that runoff would increase anywhere from three to six percent depending on location and the amount of the increase in CO2.

"Though this study focuses on Eastern U.S. forests, we know nitrogen and ozone effects are also important in South America and Europe," said co-author Adam Schlosser of the Center for Global Change Science at MIT….

A forest creek in Eagleville, Pennsylvania, shot by Mortis, Wikimedia Commons, under the terms of the GNU Free Documentation License, Version 1.2

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