PLEA Network

23 November 2015, Aljazeera, Siberia’s melting permafrost fuels climate change. Over the past year, a number of giant, mysterious holes have emerged in Siberia, some as deep as 200 metres. Scientists say the craters may be emerging because the frozen ground, or “permafrost”, that covers much of Siberia has been thawing due to climate change, allowing methane gases trapped underground to build up and explode. Permafrost is ground that is permanently frozen, where the ground temperature has remained below zero degrees Celsius for at least two years. It covers about a quarter of the northern hemisphere’s land surface. When permafrost thaws, microbes digest the plant and animal remains that were locked in the permafrost and release greenhouse gases, carbon dioxide and methane into the atmosphere. The phenomenon is a self-feeding cycle, explained Sarah Chadburn, from the University of Exeter. “Permafrost soils contain vast amounts of carbon, nearly twice as much as is currently in the atmosphere. As the permafrost thaws in a warming climate, the soil decomposes and releases carbon to the atmosphere as carbon dioxide and methane. These are greenhouse gases, and they warm the Earth even more. This leads to more permafrost thawing, more carbon release, and so the cycle continues,” Chadburn said. Read More here