Is there anything climate change won’t affect? In this most recent development, NASA reports that sea ice coverage surrounding Antarctica has exceeded 20 million square kilometers – the largest area it’s covered since measurement began in 1979. Is this proof that at the very least, climate change isn’t charging ahead as fast as scientists claim? Not so fast, says NASA.

“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, a senior scientist at NASA’s Goddard Space Flight Center.

The issue is that while sea ice in Antarctica has gained an average of 18,900 square kilometers since 1979, the ice surrounding its northern cousin, the Arctic, has shrunk by an average of 53,900 square kilometers in the same period. That’s nearly triple the rate of Antarctica’s growth.

This illustrates why scientists are more apt to use the phrase “climate change” over “global warming.” While the latter is accurate in terms of the planet’s temperature over all, it suggest that every area becomes warmer at the same time, which is not the case. “Climate change” better represents reality: Some areas that are wet become dry, while others become wetter. Dry areas become wet, while others become drier. In the case of the Arctic and Antarctic, one cold area has grown warmer while the other grows colder.

As to an explanation, scientists have several possibilities but nothing concrete as of yet. One theory is that geography plays a role, as Antarctica has no surrounding physical barriers to prevent ice formation. Changing weather patterns brought on by climate change can also play a role, as changed or wind currents can induce expansion in certain areas where colder air has been redirected.

“There hasn’t been one explanation yet that I’d say has become a consensus, where people say, ‘We’ve nailed it, this is why it’s happening,’” Parkinson said. “Our models are improving, but they’re far from perfect. One by one, scientists are figuring out that particular variables are more important than we thought years ago, and one by one those variables are getting incorporated into the models.”