Permafrost is any soil, sediment, or rock that remains frozen for at least two years. As the Arctic warms up about 4 times faster than the rest of the planet as a result of climate change, up to 65% of the region's permafrost could disappear by 2100.
Ancient carbon stored in ice can now be degraded by microorganisms, releasing carbon dioxide and methane into the atmosphere. The higher the temperature, the more greenhouse gases are released, causing temperatures to rise further.