Greenland’s Summer Mega Melt

 Extent of surface melt over Greenland's ice sheet on July 8, 2012 (left) and July 12, 2012 (right), melting shown in pink: Jesse Allen, NASA Earth Observatory and Nicolo E. DiGirolamo, SSAI and Cryospheric Sciences LaboratoryExtent of surface melt over Greenland’s ice sheet on 08 July 2012 (left) and 12 July 2012 (right), melting shown in pink: Jesse Allen, NASA Earth Observatory and Nicolo E. DiGirolamo, SSAI and Cryospheric Sciences Laboratory Satellites recorded an unprecedented rate of ice sheet melt in Greenland this month. Over the course of four days in July virtually the entire surface melted—an area larger than at any time in more than 30 years of satellite observations.

On average about half the surface area of the ice sheet melts in summer. But between 08 and 12 July 2012 the melt spread from 40 percent to 97 percent of the Greenland ice sheet.

A researcher at NASA’s Jet Propulsion Laboratory in Pasadena was analyzing radar data from the Indian Space Research Organisation’s (ISRO) Oceansat-2 satellite last week when he noticed that most of Greenland appeared to be melting.

The extreme melt coincided with a heat dome over Greenland—one of a series of unusually strong ridges of warm air dominating Greenland’s weather since May. Each successive ridge has been stronger than the previous one this summer.

Atmopsheric carbon dioxide measurements at Summit, Greenland, 1985-2010: NOAA | Earth System Reserach LaboratoryAtmospheric carbon dioxide measurements at Summit, Greenland, 1996-2010: NOAA | Earth System Research Laboratory

Even the NOAA observatory Summit Station in central Greenland—2 miles (3.2 kilometers) above sea level and near the highest point of the ice sheet—showed signs of melt. Such widespread thawing has not occurred since 1889, according to ice-core analyses.

“Ice cores from Summit show that melting events of this type occur about once every 150 years on average. With the last one happening in 1889, this event is right on time,” said Lora Koenig, a Goddard glaciologist and a member of the research team analyzing the satellite data. “But if we continue to observe melting events like this in upcoming years, it will be worrisome.” 

Thank you!

We didn't know what to expect when we told you we needed to raise $400,000 before our fiscal year closed on June 30, and we're thrilled to report that our incredible community of readers contributed some $415,000 to help us keep charging as hard as we can during this crazy year.

You just sent an incredible message: that quality journalism doesn't have to answer to advertisers, billionaires, or hedge funds; that newsrooms can eke out an existence thanks primarily to the generosity of its readers. That's so powerful. Especially during what's been called a "media extinction event" when those looking to make a profit from the news pull back, the Mother Jones community steps in.

The months and years ahead won't be easy. Far from it. But there's no one we'd rather face the big challenges with than you, our committed and passionate readers, and our team of fearless reporters who show up every day.

Thank you!

We didn't know what to expect when we told you we needed to raise $400,000 before our fiscal year closed on June 30, and we're thrilled to report that our incredible community of readers contributed some $415,000 to help us keep charging as hard as we can during this crazy year.

You just sent an incredible message: that quality journalism doesn't have to answer to advertisers, billionaires, or hedge funds; that newsrooms can eke out an existence thanks primarily to the generosity of its readers. That's so powerful. Especially during what's been called a "media extinction event" when those looking to make a profit from the news pull back, the Mother Jones community steps in.

The months and years ahead won't be easy. Far from it. But there's no one we'd rather face the big challenges with than you, our committed and passionate readers, and our team of fearless reporters who show up every day.

We Recommend

Latest

Sign up for our newsletters

Subscribe and we'll send Mother Jones straight to your inbox.

Get our award-winning magazine

Save big on a full year of investigations, ideas, and insights.

Subscribe

Support our journalism

Help Mother Jones' reporters dig deep with a tax-deductible donation.

Donate

We have a new comment system! We are now using Coral, from Vox Media, for comments on all new articles. We'd love your feedback.