More Methane A Mystery

Methane Molecule (Image from Wikimedia)

From News 24:

Washington - Levels of climate-warming methane - a greenhouse gas 25 times as potent as carbon dioxide - rose abruptly in the earth's atmosphere last year, and scientists who reported the change don't know why it occurred.

Methane, the primary component of natural gas, has more than doubled in the atmosphere since pre-industrial times, but stayed largely stable over the last decade or so before rising in 2007, researchers said on Wednesday.

This stability led scientists to believe that the emissions of methane, from natural sources like cows, sheep and wetlands, as well as from human activities like coal and gas production, were balanced by the destruction of methane in the atmosphere.

But that balance was upset starting early last year, releasing millions of metric tonnes more methane into the air, the scientists wrote in the Geophysical Research Letters.

"The thing that's really surprising is that it's coming after this period of very level emissions," said Matthew Rigby of the Massachusetts Institute of Technology (MIT).

"The worry is that we just don't understand the methane cycle very well."

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