Regional differences in global glacier retreat from 1980 to 2015

Abstract

Global warming triggers shrinking and thinning of glaciers worldwide, with potentially severe implications for human society. However, regional differences in glacier retreat and its relationship with climatic characteristics have not been conclusively demonstrated. In this study, regional changes in global glaciers based on two primary features, area change and mass balance, were investigated on the basis of data collected from published research on glacier changes. Results show that during the period 1980–2015, the rate of global glacier area shrinkage was 0.18% per year and that of global glacier mass loss was 0.25 m w.e. per year. Retreat of glaciers located at low and middle latitudes was characterized by severe area shrinkage and mass loss. Correspondingly, in the Arctic, deglaciation was characterized by ice thinning due to a low area reduction but relatively high mass loss rate. However, glaciers in high southern latitudes were in a relatively stable status. High Mountain Asia exhibited the lowest rate of area shrinkage and mass loss among glaciers located at low and middle latitudes, and a slower rate of mass loss compared with the global average. Glaciers in the Tropical Andes exhibited the fastest rate of glacier area shrinkage (−1.6% per year), whereas Antarctic and Subantarctic glaciers showed the lowest rate (−0.11% per year). For mass balance, the most negative occurred at Southern Andes (−0.81 m w.e. per year), followed by Alaska (−0.74 m w.e. per year). Only the Antarctic and Subantarctic experienced small mass gain (0.04 m w.e. per year). High levels of correlation are found between the rates of glacier retreat and annual average temperature and annual total precipitation instead of their trends. The variability of the surface climate conditions in the glacier environment plays a key role in driving these regional differences in global glacier retreat. Keywords: Glacier retreat, Regional differences, Climate change