Scientists find new global warming threat
Methane from thawing permafrost could increase global warming
The Siberian lakes, which are formed in melting permafrost as temperatures rise, have long been known to emit methane which is 23 times more powerful a greenhouse gas than carbon dioxide.
But it has been hard to quantify just how much methane was being released. A new, more accurate measuring technique was used to assess this effect during a study published today in the journal Nature.
The results suggest that the total release of methane from wetlands in the Northern Hemisphere may be between 10% and 63% higher than previously thought. Therefore scientists worry about a global warming vicious cycle that was not part of their already gloomy climate forecast: warming already under way thaws permafrost, soil that has been frozen for thousands of years. Thawed permafrost releases methane and carbon dioxide. Those gases reach the atmosphere and help trap heat on Earth in the greenhouse effect. The trapped heat thaws more permafrost and so on.
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