title: Observation-Based Estimates of Global Glacier Mass Change and Its Contribution to Sea-Level Change.
abstract: Glaciers have strongly contributed to sea-level rise during the past century and will continue to be an important part of the sea-level budget during the twenty-first century. Here, we review the progress in estimating global glacier mass change from in situ measurements of mass and length changes, remote sensing methods, and mass balance modeling driven by climate observations. For the period before the onset of satellite observations, different strategies to overcome the uncertainty associated with monitoring only a small sample of the world's glaciers have been developed. These methods now yield estimates generally reconcilable with each other within their respective uncertainty margins. Whereas this is also the case for the recent decades, the greatly increased number of estimates obtained from remote sensing reveals that gravimetry-based methods typically arrive at lower mass loss estimates than the other methods. We suggest that strategies for better interconnecting the different methods are needed to ensure progress and to increase the temporal and spatial detail of reliable glacier mass change estimates.
authors.affiliation: Institute of Geography, University of Bremen, Postfach 330 440, 28334 Bremen, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Marzeion
authors.affiliation: International Space Science Institute, Hallerstrasse 6, 3012 Bern, Switzerland.
authors.forename: N
authors.initials: N
authors.lastname: Champollion
authors.affiliation: Department of Geography, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland.
authors.forename: W
authors.initials: W
authors.lastname: Haeberli
authors.affiliation: Asiaq Greenland Survey, Qatserisut 8, 3900 Nuuk, Greenland.
authors.forename: K
authors.initials: K
authors.lastname: Langley
authors.affiliation: Department of Geosciences, University of Oslo, P.O. Box 1047, Blindern, 0316 Oslo, Norway.
authors.forename: P
authors.initials: P
authors.lastname: Leclercq
authors.affiliation: Department of Geography, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland.
authors.forename: F
authors.initials: F
authors.lastname: Paul
keywords: Glacier mass change; Glacier modeling; In situ and satellite observations; Mean sea level