Greenland’s colossal ice sheet is melting early, and guess what – we’re to blame. According to the climatologists at the Danish Meteorological Institute (DMI), 12 percent of the ice sheet’s surface area is already showing signs of melting, and this is, without a doubt, due to unseasonably warm temperatures and rain induced by man-made climate change.
This degree of melting would be expected in any scenario at the onset of summer, but is completely unprecedented halfway through April. In fact, this finding means that it has destroyed the record for early Greenland melting by over three weeks. Even in 2012, when 95 percent of the ice sheet was melting, it still began later in the year.
“It's disturbing,” Peter Langen, a climatologist at DMI, said in a statement. “Something like this wipes out all kinds of records, you can't help but go this could be a sign of things we're going to see more often in the future.”
This frigid mass – which at 1.7 million square kilometers (656,000 square miles) makes it roughly the same size as Mexico – melts and refreezes on an annual summer-winter cycle. However, what is currently being observed can only be due to the year-on-year increases in sea surface, land and atmospheric temperatures.
The capital of this Danish territory, Nuuk, reached 16.6°C (62°F) this Monday, crushing the previous high-temperature record for that month by 3.5°C (6.5°F). Further inland, temperatures were warmer than San Francisco.
Left: Maps showing the unprecedented early melting extent (red) along the Greenland Ice Sheet. Right: Ice melt as a percentage of total area. The gray-shaded area denotes the average melt for each month from 1990-2013; the blue line marks the current melting extent. DMI
As in the summer months, higher temperatures cause the top of the ice sheet to melt, while warmer waves chip away at the base of icy dams, keeping land-based ice from falling into the ocean. A warmer climate also encourages greater rates of precipitation; consequently, pools of warmer water delivered by increased rainfall help to break apart huge masses of ice.
All of these mechanisms conspire to disintegrate Greenland’s Ice Sheet – and thanks to man-made climate change, things are happening fair earlier, and far worse, than expected. The Greenland Ice Sheet has shed about 3.5 billion tonnes (3.9 billion tons) of ice since 2003, and this early April melting could be a sign that the annual rate of ice shedding is due to increase.
“Things are getting more extreme and they're getting more common,” noted NASA ice scientist Walt Meier. “One freakish thing every once in a while you might expect. But we're getting these things more often and that's an indication of climate change.”
Unlike the collapse of ice shelves, the melting of ice sheets directly and immediately contributes to sea level rise. Within the next century, Greenland’s melting is set to contribute at least 6 meters (20 feet) in sea level rise.
Studies confirm that the terrestrial advance of the oceans can only be halted by 2100 if the Paris climate agreement warming target of 2°C (3.6°F) is adhered to; otherwise, researchers have all but confirmed that it will doom coastal metropolises like New York City and Miami to eventual oblivion.