The Arctic holds more than a trillion tons of carbon, locked in the frozen soil known as permafrost. That’s more than twice as much carbon as there is in the atmosphere itself, according to a 2013 report from the National Academy of Sciences. And as the climate warms under its growing blanket of human-generated greenhouse gases, thawing permafrost could release some of that carbon into the atmosphere.
That could amplify the effect of global warming by boosting CO2 levels higher than they would otherwise be in a so-called feedback loop and making the consequence of warming, including rising seas, more intense and prolonged heat waves and droughts and distorted weather patterns even more severe. They could also lead to more thawing of permafrost and the release of even more CO2, starting the cycle again.
How much carbon will be released, however, and how much extra warming is likely to result, has been a matter of dispute in recent years. Some researchers have argued that that the effects will be horrific, while others say they’ll be significant but less dramatic. And now, a new report in Nature — the most comprehensive study ever done on the permafrost feedback loop, has come down firmly in the “significant” camp. “The permafrost carbon is not going to explode into the atmosphere catastrophically within just a few years,” Ted Schuur, a permafrost expert at Northern Arizona University, said. “It’s more like it will seep out slowly in small amounts in a very large number of places.”
http://www.weather.com/science/environment/news/thawing-permafrost-climate-threat
No comments:
Post a Comment