Greenland’s massive ice sheet has started its annual summer melt earlier than ever before.
Researchers at the Danish Meteorological Institute (DMI) first thought their models were wrong.
“We had to check that our models were still working properly,” said Peter Langen, a climate scientist at DMI. Unfortunately, their models were right.
Nearly 12% of Greenland’s nearly 656,000 square miles of ice saw some melting this week, the earliest date on record for the start of the summer melt season.
Climate stations on the ice sheet were reporting temperatures above 50 degrees Fahrenheit. The summit of the ice sheet has also been record warm. On Tuesday, it reached 20.3°F (-6.5°C), which is extremely mild for this time of year and is roughly 40°F above normal.
While the total amount of ice lost isn’t huge in terms of total volume, such early melting sets up a feedback mechanism that contributes to further melting.
Greenland’s ice sheet — roughly the size of Alaska — is important because it represent one of the most massive stores of ice on the planet. If it were all to melt, it would raise oceans about 20 feet.