ABSTRACT
Greater greenhouse warming in the Arctic than elsewhere is predicted by most general circulation models of the atmosphere on account of positive feedbacks between air temperature, ice extent and surface albedo. However, weather observations, ice sheet
Figure 10.1 Location sketch map of the Arctic
accumulation layers and glacier mass balance measurements all indicate widespread cooling on land in the Arctic for a decade or two in the latter half of the twentieth century (Braithwaite et al. 1992, Kahl et al. 1993). As in most other parts of the world, temperatures fell in the 1960s and 1970s, and then there was renewed warming at the end of the millennium (Lefauconnier and Hagen 1990, Serreze et al. 2000). Overpeck et al. (1997) concluded that Arctic temperatures in the twentieth century were the highest in the last four centuries, with an overall warming of 2 °C concentrated in the period 1840-1960. Arctic glaciers at low altitudes have
responded to twentieth-century warming by retreating almost everywhere.2
