Sea ice around Antarctica reached a record extent this year, but don’t think that’s the end of melting in the seas around the poles, NASA says: That region’s upward trend is a third of the magnitude of sea ice loss in the Arctic. NASA said Tuesday those differences don’t conflict with prevailing theory about global climate change. “The planet as a whole is doing what was expected in terms of warming. Sea ice as a whole is decreasing as expected, but just like with global warming, not every location with sea ice will have a downward trend in ice extent,” said Claire Parkinson of NASA’s Goddard Space Flight Center.

The maximum extent of sea ice in Antarctica this year occurred Sept. 20, at 7.78 million square miles (20.14 million square kilometers), NASA said, citing data from the National Snow and Ice Data Center. That was a day after the extent exceeded 20 million square kilometers (7.72 million square miles) for the first time. Why sea ice is growing around Antarctica isn’t clear, but scientists say that could be caused by changes in wind patterns or melting of ice on the continent’s edges, leading to fresher water that freezes at higher temperatures, or other reasons.

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