A Reconciled Estimate of Ice-Sheet Mass Balance

• DOI: 10.1126/science.1228102
• Publication Date: 2012-11-29T19:15:18Z
• Authors: Andrew Shepherd; Erik R. Ivins; Geruo A; Valentina R. Barl...; Mike J. Bentley; Srinivas Bettadpur; Kate H. Briggs; David H. Bromwich; René Forsberg; Natalia Galin; Martin Horwath; Stan Jacobs; Ian Joughin; Matt A. King; Jan T. M. Lenaerts; Jilu Li; Stefan R. M. Ligt...; Adrian Luckman; Scott B. Luthcke; Malcolm McMillan; Rakia Meister; Glenn Milne; Jeremie Mouginot; Alan Muir; Julien P. Nicolas; John Paden; Antony J. Payne; Hamish Pritchard; Eric Rignot; Helmut Rott; Louise Sandberg S...; Ted A. Scambos; Bernd Scheuchl; Ernst J. O. Schrama; Ben Smith; Aud V. Sundal; Jan H. van Angelen; Willem J. van de ...; Michiel R. van de...; David G. Vaughan; Isabella Velicogna; John Wahr; Pippa L. Whitehouse; Duncan J. Wingham; Donghui Yi; Duncan Young; H. Jay Zwally
• Keywords: 550; General Science & Technology; Climate Change; Greenland; Antarctic Regions; 551; 01 natural sciences; Climate Action; 13. Climate action; Geographic Information Systems; Ice Cover; 14. Life underwater; 0105 earth and related environmental sciences

Warming and Melting

Mass loss from the ice sheets of Greenland and Antarctica account for a large fraction of global sea-level rise. Part of this loss is because of the effects of warmer air temperatures, and another because of the rising ocean temperatures to which they are being exposed.

Joughin et al.

(p. 1172 ) review how ocean-ice interactions are impacting ice sheets and discuss the possible ways that exposure of floating ice shelves and grounded ice margins are subject to the influences of warming ocean currents. Estimates of the mass balance of the ice sheets of Greenland and Antarctica have differed greatly—in some cases, not even agreeing about whether there is a net loss or a net gain—making it more difficult to project accurately future sea-level change.

Shepherd et al.

(p. 1183 ) combined data sets produced by satellite altimetry, interferometry, and gravimetry to construct a more robust ice-sheet mass balance for the period between 1992 and 2011. All major regions of the two ice sheets appear to be losing mass, except for East Antarctica. All told, mass loss from the polar ice sheets is contributing about 0.6 millimeters per year (roughly 20% of the total) to the current rate of global sea-level rise.