Some glaciers in Greenland melt slower in warm summers than in cool ones, according to a new study. Following the analysis of satellite data over five years, a UK-led scientific team has concluded that the Greenland icecap may be more resilient against global warming than previously thought.
The study suggests that while the icecap is not “safe from climate change”, the acceleration of glacier flow could prove to be of less consequence than suggested by some experts.
In all of the years studied by the scientists, the onset of summer increased the flow of meltwater between the bottom of the glacier and the rock beneath it. In warmer years, however, the acceleration was found to stop again early in the season, while in relatively cool summers it did not. By late summer in the warmer years, the glaciers were found to have melted 60 percent slower, even though the process started earlier.
“In their last report in 2007, the Intergovernmental Panel on Climate Change (IPCC) concluded they weren’t able to make an accurate projection of future sea levels because there were a couple of processes by which climate change could cause additional melt from the ice sheet,” said Andy Shepherd from the University of Leeds who carried out the study. “We’re addressing one of those processes and saying that according to the observations, nothing will change, so that process can probably be ruled out.”
The explanation offered for the phenomenon is that in hotter years, the increased amount of meltwater runs into channels below the ice and, therefore, does not lubricate the glaciers themselves so effectively. The results are backed up by further studies carried out in Greenland and other temperate regions of the world.