Greenland’s ice loss massive – and speeding up

A new study by 16 authors has calculated just how much ice the Greenland ice sheet has lost since the year 1900. And the number, says the paper just out in the journal Nature, is astounding: 9.103 gigatons (a gigaton is a billion metric tons).

That's more than 9 trillion tons in total, Washington Post reports.

And moreover, the rate of loss has been increasing, the research finds, with a doubling of annual loss in the period 2003 to 2010 compared with what it was throughout the 20th century.

The study was led by Kristian K. Kjeldsen of the Natural History Museum of Denmark at the University of Copenhagen.

The complex work involved inferring the loss of mass of the total ice sheet over a very large stretch of time using a merger of multiple information sources - the distinct marks left by retreating glaciers on the landscape, extensive aerial photography from 1978 through 1987, and - beginning in 1983 - satellite and aircraft observations.

All were merged to provide the new mass loss estimates.

- It's the first observational based study that shows where Greenland has lost its mass over the last 110 years, said Kurt H. Kjær, the paper's senior author and also of the Natural History Museum of Denmark at the University of Copenhagen.