TY - Report PY - 2012 T1 - Policy implications of warming permafrost PB - United Nations Environment Programme DO - https://doi.org/APO-32074 UR - https://apo.org.au/node/32074 AB - Permafrost is perennially frozen ground occurring in about 24% of the exposed land surface in the Northern Hemisphere. The distribution of permafrost is controlled by air temperature and, to a lesser extent, by snow depth, vegetation, orientation to the sun and soil properties. Any location with annual average air temperatures below freezing can potentially form permafrost. ER -