revkin:

Greenland melt season in overdrive. More vid. (h/t @cryocity). High melt rate meshes with Jason Box reports on surface reflectivity of ice sheet being at modern low (darker = more sun absorption). It’s important to examine this in a longer time context, though. Earlier Jason Box research:

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DISCOVERY OF HISTORICAL PHOTOS SHEDS LIGHT ON GREENLAND ICE LOSS

COLUMBUS, Ohio - A chance discovery of 80-year-old photo plates in a Danish basement is providing new insight into how Greenland glaciers are melting today.

Researchers at the National Survey and Cadastre of Denmark - that country’s federal agency responsible for surveys and mapping - had been storing the glass plates since explorer Knud Rasmussen’sexpedition to the southeast coast of Greenland in the early 1930s.

In this week’s online edition of Nature Geoscience, Ohio State University researchers and colleagues in Denmark describe how they analyzed ice loss in the region by comparing the images on the plates to aerial photographs and satellite images taken from World War II to today.

Taken together, the imagery shows that glaciers in the region were melting even faster in the 1930s than they are today, said Jason Box, associate professor of geography and researcher at the Byrd Polar Research Center at Ohio State. A brief cooling period starting in the mid-20th century allowed new ice to form, and then the melting began to accelerate again in the 2000s…

Finally, worth keeping in mind other work showing that all surface melting doesn’t necessarily lead to the sea (even thought a lot does, as these videos show!).

For example, see recent work showing this is not a simple process: “Using observations from ESA’s veteran ERS-1 satellite, which in July will have been in orbit for 20 years, new research suggests that the internal drainage system of the ice sheet adapts to accommodate more meltwater, without speeding up the flow of the glacier.”