This image might look pretty, but it holds a glum message: it shows that the Antarctic ice sheet is now losing 159 billion tonnes of ice each year.
We already knew that Antarctica was melting, but this image—created by a team of scientists from the UK's Centre for Polar Observation and Modelling using data from CryoSat—shows exactly where it's happening. Cryosat is a satellite that carries a radar altimeter capable of measuring the surface height variation of ice in fine detail— allowing scientists to record changes in ice volume.
The results show that Antarctica's ice sheet is now losing 159 billion tonnes of ice a year – twice as much as when it was last surveyed. In the image, red indicates ice thinning while blue colorings indicates thickening. Deep, dark red—of which there happens to be a lot!—is a Bad Thing. Dr Malcolm McMillan, lead author of the study, explains:
"We find that ice losses continue to be most pronounced along the fast-flowing ice streams of the Amundsen Sea sector, with thinning rates of 4-8 m per year near to the grounding lines – where the ice streams lift up off the land and begin to float out over the ocean – of the Pine Island, Thwaites and Smith Glaciers."
Those losses alone are enough to raise global sea levels by 0.45 millimeters each year—and it shows no signs of slowing unless we do something drastic. [ESA]