The whole of Greenland's ice sheet is likely to experience some degree of melting over the next decade.
Jason Box at the Ohio State University in Columbus and his team combined satellite measurements of surface albedo — how much sunlight the ground reflects — with models of surface air temperature and solar radiation hitting the surface for the past 12 summers. The researchers found that positive albedo feedback — whereby melting ice reduces surface reflectivity, leading to faster melting — has doubled the ice sheet's surface melt rate since 2000.
The authors identified three ways in which recent warm summers could have contributed to the reduced albedo: surface heating due to unusually warm air currents creates larger snow grains that reflect less sunlight; less cloudy skies increase direct heating from sunlight; and reduced summer snowfall results in a darker surface.
Another warm decade could mean that Greenland will absorb instead of resist the heat from 24-hour sunlight, leading to expansion of the melt area to encompass the entire ice sheet. This process has already begun, with an estimated 97% of Greenland's ice sheet having shown surface melting by mid-July of this year.
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Melting triggers more melting. Nature 488, 433 (2012). https://doi.org/10.1038/488433d
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DOI: https://doi.org/10.1038/488433d