Climate Change and Hazard Zonation in the Circum-Arctic Permafrost Regions

The permafrost regions currently occupy about one quarter of the Earth's land area.Climate-change scenarios indicate that global warming will be amplified in the polarregions, and could lead to a large reduction in the geographic extent of permafrost.Development of natural resources, transportation networks, and human infrastructurein the high northern latitudes has been extensive during the second half of the twentiethcentury. In areas underlain by ice-rich permafrost, infrastructure could be damagedseverely by thaw-induced settlement of the ground surface accompanying climatechange. Permafrost near the current southern margin of its extent is degrading, andthis process may involve a northward shift in the southern boundary of permafrostby hundreds of kilometers throughout much of northern North America and Eurasia.A long-term increase in summer temperatures in the high northern latitudes couldalso result in significant increases in the thickness of the seasonally thawed layerabove permafrost, with negative impacts on human infrastructure located on ice-richterrain. Experiments involving general circulation model scenarios of global climatechange, a mathematical solution for the thickness of the active layer, and digitalrepresentations of permafrost distribution and ice content indicates potential forsevere disruption of human infrastructure in the permafrost regions in response toanthropogenic climate change. A series of hazard zonation maps depicts generalizedpatterns of susceptibility to thaw subsidence. Areas of greatest hazard potential includecoastlines on the Arctic Ocean and parts of Alaska, Canada, and Siberia in whichsubstantial development has occurred in recent decades. Copyright Kluwer Academic Publishers 2002