Sep 1, 2015

Historically unprecedented global glacier decline in the early 21

Zemp, Michael; Frey, Holger; Gärtner-Roer, Isabelle; Nussbaumer, Samuel U.; Hoelzle, Martin; Paul, Frank; Haeberli, Wilfried; Denzinger, Florian; Ahlstrøm, Andreas P.; Anderson, Brian; Bajracharya, Samjwal; Baroni, Carlo et al
Journal of Glaciology
  • Observations show that glaciers around the world are in retreat and losing mass
  • States that glacier monitoring activities—internationally coordinated for over a century—provide an unprecedented dataset of glacier observations from ground, air and space
  • States that glacier studies generally select specific parts of these datasets to obtain optimal assessments of the mass-balance data relating to the impact that glaciers exercise on global sea-level fluctuations or on regional runoff
  • Provides an overview and analysis of the main observational datasets compiled by the World Glacier Monitoring Service (WGMS)
  • The dataset on glacier front variations (approximately 42,000 since 1600) delivers clear evidence that centennial glacier retreat is a global phenomenon
  • Finds that intermittent readvance periods at regional and decadal scale are normally restricted to a subsample of glaciers and have not come close to achieving the maximum positions of the Little Ice Age (or Holocene)
  • Glaciological and geodetic observations (approximately 5,200 since 1850) show that the rates of early 21st-century mass loss are without precedent on a global scale, at least for the time period observed and probably also for recorded history
  • Concludes that this strong imbalance implies that glaciers in many regions will very likely suffer further ice loss, even if climate remains stable