Arctic Permafrost May Thaw by 2100

Climate system model results from the National Center for Atmospheric Research (NCAR) indicate that increasing global temperatures may thaw the top 10 feet or more of permafrost in the Northern Hemisphere. Permafrost is defined as soil that remains frozen through the summer months over a period of at least two years. As reported in the December 17 issue of Geophysical Research Letters, over half of the total area covered by permafrost could be thawed by 2050. The NCAR study is the first to include the state of permafrost in a global computer climate simulation model. According to NCAR, "Recent warming has degraded large sections of permafrost across central Alaska, with pockets of soil collapsing as the ice within it melts. The results include buckled highways, destabilized houses, and "drunken forests"--trees that lean at wild angles. In Siberia, some industrial facilities have reported significant damage. Further loss of permafrost could threaten migration patterns of animals such as reindeer and caribou." Melting permafrost could also contribute to rising sea levels. The map at right shows how little permafrost may be left (dark blue color) in 75 years from now.