New source of global warming gas found: plants

New source of global warming gas found: plants
Wed Jan 11, 1:06 PM ET
German scientists have discovered a new source of methane, a greenhouse gas that is second only to carbon dioxide in its impact on climate change.
The culprits are plants.
They produce about 10 to 30 percent of the annual methane found in the atmosphere, according to researchers at the Max-Planck Institute for Nuclear Physics in Heidelberg, Germany....
.... Methane, which is produced by city rubbish dumps, coal mining, flatulent animals, rice cultivation and peat bogs, is one of the most potent greenhouse gases in terms of its ability to trap heat.
Concentrations of the gas in the atmosphere have almost tripled in the last 150 years. About 600 million tonnes worldwide are produced annually.
The scientists said their finding is important for understanding the link between global warming and a rise in greenhouse gases.
Scientists had previously thought that plants could only emit methane in the absence of oxygen.....
.... David Lowe, of the National Institute of Water and Atmospheric Research in New Zealand, said the findings are startling and controversial.
"Keppler and colleagues' finding helps to account for observations from space of incredibly large plumes of methane above tropical forests," he said in a commentary on the research.
But the study also poses questions, such as how such a potentially large source of methane could have been overlooked and how plants produced it.
"There will be a lively scramble among researchers for the answers to these and other questions," Lowe added.
Copyright © 2006 Reuters Limited.

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