Glaciers and climate change

Abstract

Concurrent with atmospheric warming glaciers around the world are rapidly retreating, thinning, and losing mass. While total volume compared with the ice sheets in Greenland and Antarctica is small, glaciers outside the ice sheets have contributed significantly to recent global sea level rise. On average, these glaciers experienced only slightly negative mass budgets in the 1960s–80s, but mass loss has increased considerably since. While air temperature is the primary driver of global glacier mass loss, many feedback mechanisms, for example, due to changing glacier geometry, as well as ice–water interactions at marine- or lake-terminating glacier fronts, complicate the glacier response. Advances of individual glaciers are rare and often linked to dynamical processes largely unrelated to climate. Globally, glaciers have been projected to lose approximately 18%–36% of their 2015 ice volume by the end of the 21st century depending on the emission pathways. Continued monitoring of the world's glaciers using in situ and satellite observations and further studies to advance process understanding and model development are needed to reduce the uncertainties in glacier mass–change assessments and projections.