PLEA Network

9 December 2015, Washington Post, How the Earth itself could undermine a Paris climate agreement. PARIS — With only three days left, tensions here are rising as countries race to resolve outstanding differences and forge an agreement that — hopefully — will set the planet on a path to avoiding the worst consequences of climate change. The goal is an agreement that would set the world on a path to limit warming to below 2 degrees Celsius, or perhaps even 1.5 degrees Celsius, above pre-industrial levels. But at a news conference here at the Le Bourget conference center Wednesday morning, scientists pointed out a factor that could make hitting these targets quite a lot harder. It’s called permafrost. As the planet warms, this frozen northern soil is going to continue to thaw — and as it thaws, it’s going to release carbon dioxide and methane into the air. A lot of it, it turns out. Potentially enough to really throw off the carbon budgets that have been calculated in order to determine the maximum emissions that we can release and still have a good chance of keeping warming to 2 C or below it. In particular, Susan Natali of the Woods Hole Research Center explained Wednesday that with a very high level of warming, permafrost emissions this century could be quite large indeed. Natali used numbers from the 2013 report of the United Nations’ Intergovernmental Panel on Climate Change, which found that humans can only emit about 275 more gigatons, or billion tons, of carbon (about 1,000 gigatons of carbon dioxide, which has a greater molecular weight) to have a greater than 66 percent chance of limiting warming to 2 degrees C. But out of that limited budget, she said, permafrost emissions could take up some 150 of those gigatons (or about 550 gigatons of carbon dioxide). Read More here