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Headlines about global warming frequently refer to melting ice, but a new study reports that Antarctica may actually have gained mass.
The study, published in the Journal of Glaciology, analyzed satellite data from two time periods. It concludes that during both periods, the amount of snow gained on the continent was greater than the amount of ice lost to melting. For the most recent period, between 2003 and 2008, the paper reports that the continent had a net gain of 82 gigatons per year. (A gigaton of ice is a billion metric tons.)
Jay Zwally, the lead author on the paper and a scientist at the NASA Goddard Space Flight Center, said that this study should not fuel climate change denial.
"Climate warming is taking place in the Antarctic, but to a lesser extent than it is in the Arctic or the rest of the world," he told VICE News. "It's affecting part of Antarctica, the peninsula and West Antarctica, which are losing mass faster now than they did 10-15 years ago. But the large interior of Antarctica is gaining mass."
Zwally said the Antarctic findings suggest that the world's frozen southern continent is not adding to global sea level rise. Because of this, he said that another factor — perhaps the ocean's thermal expansion — is a bigger part of the equation when it comes to sea level rise. Seas are rising at a rate of three millimeters per year.
There is no guarantee that Antarctica will continue to gain more mass than it is losing in the future, Zwally cautioned.
But Gavin Schmidt, who directs the NASA Goddard Institute for Space Studies and was not affiliated with the study, said that data from a pair of satellites called GRACE, which measure gravity, actually points towards a net loss of ice on the Antarctic continent in more recent years.
Schmidt said that there are two methods for measuring the mass of an ice sheet. The first measures gravity, and the second measures the elevation of the top of the ice sheet. Both methods need to take different variables into account to be accurate. The method used in this most recent study measured the ice sheet's elevation, and the most recent time period it considered ended in 2008.
"I would pin more weight to the GRACE data than to this latest paper," Schmidt told VICE News.
Robin Bell, a research professor at Columbia University's Lamont-Doherty Earth Observatory, said the method that uses laser altimetry from a satellite to measure the elevation of the ice, which was used for one of the time periods described in the paper, can show greater mass gains than alternative methods.
The edges of Antarctica are thinning, she said. Indeed, earlier this year NASA said that the remainder of the continent's Larsen B Ice Shelf was "quickly weakening." But one problem with measuring the gains to the continent, Bell said, is understanding the process of snow becoming ice on the surface.
"To me this points out that we still don't understand everything about how snow turns into ice and how the ice sheets are changing," Bell said.
Follow Rob Verger on Twitter: @robverger