Which part do you have difficulty understanding?From the start...

Which part do you have difficulty understanding?

From the start of satellite observations in 1979 to 2014, total Antarctic sea ice increased by about 1 percent per decade. Whether the increase was a sign of meaningful change is uncertain because ice extents vary considerably from year to year around Antarctica. For three consecutive Septembers from 2012 to 2014, satellites observed new record highs for winter sea ice extent. These highs occurred while the Arctic was seeing record lows.

https://earthobservatory.nasa.gov/world-of-change/sea-ice-antarctic

Everything to do with the unpredictable Mother Nature