Yeah, that wording is clunky. I guess, according to the article, the ice is known to melt and return in a cyclical pattern every year. This year almost a million square miles of ice did not form as expected.

Right now, it's winter in the southern hemisphere. Sea ice should be expanding around Antarctica, but it's doing so much less than previous years. It's so bad there's a chance there won't be any sea ice by the time it's mid summer there, in December/January/February. If that happens, there's nothing to stop the land glaciers from slipping into the sea and significantly raising sea levels worldwide. Could be like 10 feet of sea level rise depending on what happens. (Thwaites Glacier has been named in many articles as especially precarious and able to contribute 10 feet on its own.)