As the Arctic heats up at a rate twice that of the rest of the globe and as sea ice and glaciers turn to water, the world's permafrost is also thawing. A recent review article in the journal Nature found that as the unfrozen organic matter decays, vast stores of carbon in the permafrost could be released into the atmosphere. When that happens, it will trigger a centuries-long, unstoppable feedback system, in which warming will release carbon, which will trigger more warming, which will release more carbon. This infographic shows how and why. Read the related story here.