New research published in Nature Climate Change this week points to increased melting of the ice sheet that currently covers Greenland and thus a greater factor in sea-level rise. According to its summary:
“The Greenland ice sheet has been one of the largest contributors to global sea-level rise over the past 20 years, accounting for 0.5 mm yr−1 of a total of 3.2 mm yr−1. A significant portion of this contribution is associated with the speed-up of an increased number of glaciers in southeast and northwest Greenland. Here, we show that the northeast Greenland ice stream, which extends more than 600 km into the interior of the ice sheet, is now undergoing sustained dynamic thinning, linked to regional warming, after more than a quarter of a century of stability. This sector of the Greenland ice sheet is of particular interest, because the drainage basin area covers 16% of the ice sheet (twice that of Jakobshavn Isbræ) and numerical model predictions suggest no significant mass loss for this sector, leading to an under-estimation of future global sea-level rise. The geometry of the bedrock and monotonic trend in glacier speed-up and mass loss suggests that dynamic drawdown of ice in this region will continue in the near future.” (emphasis added)
According to one news report, the northeast region of Greenland’s ice sheet retreated 12.4 miles between 2003 and 2012 after a period of particularly high temperatures. This resulted in 10 billion tons of water added to the ocean each year of that nine-year span. Greenland contributes approximately .012 to .13 inches annually to sea-level rise, accounting for almost one-sixth of annual sea-level rise.