Historically unprecedented global glacier changes in the 1 early 21st century

ZEMP, MICHAEL; FREY, H.; GÄRTNER-ROËR, ISABELLE; NUSSBAUMER, S.U.; HOELZLE, MARTIN; PAUL, FRANK; HAEBERLI, WILFIRIED; DENZIGER, FLORIAN; AHLSTROM, ANDREAS P.; ANDERSON, BRIAN; BAJCHARYA, SAMJWAL; BARONI, CARLO; BRAUN, LUDWIG; CÁCERES, BOLIVAR; CASASSA, GINO; COBOS, GUILLERMO; DÁVILA, LUZMILA; DELGADO GRANADOS, HUGO; DEMUTH, MICHEL; ESPIZUA, L. E.; FISCHER, ANDREA; FUJITA, KOJI; GADEK, BOGDAN; GHAZANFAR, ALI; HAGEN, JON OVE; HOMLUND, PER; KARIMI, NEAMAT; LI, ZHONGQIN; PELTO, MAURI; PITTE, P.; POPOVNIN, VICTOR; PORTOCARRERO, CESAR; REINER, PRINZ; SANGEWAR, CHANDRASHEKHAR; SEVERSKIY, IGOR; SIGURDSSON, ODDUR; SORUCO, ALVARO; USUBALIEV, RYSKUL; VINCENT, C.

JOURNAL OF GLACIOLOGY

INT GLACIOL SOC

Lugar: Londres; Año: 2015 vol. 61 p. 745 - 762

0022-1430

Over the past decades, glaciers around the globe have been observed to be losing mass and retreating. This information, obtained from glacier monitoring activities and coordinated internationally for more than a century, has resulted in an unprecedented dataset of glacier observations from ground, air and space. Typically, glacier studies use selected parts of these datasets in order to best assess the mass balance data with regard to the extent to which glaciers contribute to global sea‐level fluctuations or to regional runoff. In this study we provide an overview and analysis of the main observational datasets compiled by the WGMS, from the most recent back to the earliest observations. The dataset on glacier front variations (about 42,000 since 1600) deliver clear evidence that centennial glacier retreat is a global phenomenon. Intermittent re‐advance periods at regional and decadal scale are generally 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 (about 5,200 since 1850) show that rates of early 21st century mass loss are unprecedented on a global scale at least since beginning of observational records and, as indicated by reconstructions from written and pictorial sources, even for the time period of recorded history. The largest negative mass budgets have occurred in one of the last two decades, depending on the region. This strong imbalance implies that glaciers in many regions will very likely suffer further ice loss, even under a constant climate.