One quarter of Alaska permafrost could melt by 2100 – US Geological Survey

Study raises concerns over accelerating climate change as the icy mass under state's surface releases carbon into atmosphere

Up to a quarter of the permafrost that lies underneath the surface of Alaska could melt by the end of the century, spewing long-held carbon into the atmosphere and helping accelerate climate change, US government scientists have predicted.

The US Geological Survey used satellite and on-ground data to estimate that 38% of mainland Alaska has permafrost, a band of soil, rock or sediment that is frozen underground for at least two consecutive years. In Fairbanks, Alaska, the soil has been frozen for several thousand years at just 30 to 40cm underground, with only the upper level of soil thawing every summer before freezing again in winter.