The average sea ice extent surrounding Antarctica hit a record low as satellite data shows it is well below any previous winter level on record, according to a BBC report.

It’s a troubling new benchmark for a region that once seemed to be under no immediate threat from global warming.

According to experts, an unstable Antarctica could have far-reaching consequences. Antarctica’s vast ice sheet regulates the planet’s temperature, as the white surface reflects the sun’s energy back into the atmosphere and also cools the water below and near it.

Thus, Antarctica could turn from the earth’s refrigerator to a radiator, experts say.

Ice floating on the surface of the Antarctic Ocean is now less than 17 million square kilometers – that’s 1.5 million square kilometers of sea ice less than the September average and well below previous winter record lows.

Scientists are still trying to determine all the factors that led to this year’s record low.

In a year when many global heat and ocean warming records have been broken, some scientists insist that the decline in sea ice is what we should be watching.

The sea ice forms when winter prevails in the area there, i.e. March to October and it acts as a protective filter that prevents ocean warming.

As more sea ice disappears, it exposes dark areas of the ocean, which absorb sunlight instead of reflecting it, meaning heat energy is added to the water, which in turn melts more ice.