Recent Greenland Ice Sheet Observations Summarized in New Report
15.12.2009 - Land & Geology, Ice & Snow, Arctic
A new report compiled by some of the world's leading experts and issued by the Arctic Council's Arctic Monitoring and Assessment Programme (AMAP) synthesizes the latest findings (peer-reviewed scientific material available before the spring of 2009) on the Greenland Ice Sheet. Entitled "The Greenland Ice Sheet in a Changing Climate", the report is a preliminary product under the Arctic Council's "ClimateChange and the Cryosphere: Snow, Water, Ice and Permafrost in theArctic" (SWIPA) project.
Among the most alarming findings of the report is the increased discharge of icebergs over the past decade, from 330 billion tonnes in 1995 to 430 billion tonnes in 2005. This increase highlights the warming that has occurred in Greenland over the past 50 years, more than doubling the average temperatures over Greenland. It also mentions that mass balance of the Greenland Ice Sheet - which two decades ago was more or less in balance - has changed, with surface melting and iceberg discharge increasing considerably.
The study also shows that estimates derived from current models might be underestimating the Greenland Ice Sheet's potential contribution to sea level rise by 2100. Many current estimates put the potential rise at 5 to 10cm; yet if the speed at which ice discharges from the Greenland Ice Sheet were to increase, it could contribute as much as 20 cm to global sea levels by 2100, and when meltwater from other land ice and thermal expansion of the oceans is accounted for, sea levels could rise as much as one metre by the end of the century.
While many scenarios predict it would take at least 3,000 years for the Greenland Ice Sheet to melt completely, it is possible that destabilizing tipping points could be reached much sooner. As the single largest body of freshwater ice in the Northern Hemisphere, it could contribute as much as 7 metres to global sea levels if it were to melt completely.
The report goes on to mention that while impacts on local communities are thought to be mild in comparison to global climate, and that people living in subsistence communities will be the most directly affected by climate change. However at the same time it points out that socio-economic, cultural and demographic influences on a local and global scale will have a greater effect on local communities.
