A longer-than-usual melt season in 2010 proved a record-setter in Greenland. Melting started early, and lasted longer than usual, and in all, melting lasted 50 days longer than average. This map image shows last year compared to number of melts days on average between 1979 and 2009.
The redder, the more days of snow and ice melt there were.
NASA's Earth Observatory puts it in context:
The long melt season primarily affected southern and western Greenland, where communities experienced their warmest year on record. After a warm, dry winter, temperatures were particularly high in the spring, getting the melt season off to a strong start. The early melting set the tone for the rest of the season, leading to more melting all the way into mid-September.
The increasing melting trend over Greenland can be observed from the figure. Over the past 30 years, the area subject to melting in Greenland has been increasing at a rate of ~ 17,000 Km2/year.
This is equivalent to adding a melt-region the size of Washington State every ten years. Or, in alternative, this means that an area of the size of France melted in 2010 which was not melting in 1979.
So, in fact, our headline understates the facts. Greenland is losing a France-sized area of ice more than it was losing 30 years ago. (That seemed a little cumbersome for a headline.) It's worth noting here that an incredible amount of water is stored in Greenland's ice sheet. The ice sheets on Greenland and Antarctica are the biggest sea level threats, as they're land-based, so when they melt, it adds water volume to the ocean. (As opposed to ice caps, which are already floating on the sea and don't really have any impact on sea levels when they melt. Though there are other troubling impacts.)
Three miles thick in some parts, there's enough ice on Greenland that, if it were all to melt, sea levels would rise about 20 feet. Current models don't anticipate that happening anytime soon—not this century, at least—but then again, the melt is fast exceeding pretty much all models have predicted thus far.
All the doom and gloom aside for a moment, there is something just plainly beautiful about the patterns of the rivers and superglacial lakes and waterfalls cutting through Greenland's ice sheet. Tedesco has some video from his latest research trip:
There are also more beautiful photos like the one up top on his blog.
Photo: M. Tedesco