Antarctic ice is melting fast

The sea ice surrounding Antarctica is at a staggeringly low level, say scientists.

Normally in mid-September, the end of winter in the southern hemisphere, ice near the South Pole is at a high level.

But this year, satellite readings reported by the US National Snow and Ice Data Center (NSIDC) indicate that the ice level is abnormally low – in fact, the lowest it has ever been.

On average the ice peaks at 18.5mn square kilometres in late September, and then drops to 2.5mn square kilometres by the second half of February.

But in February of 2023 sea ice levels were at a record low of 1.8mn square kilometres and they have been below average ever since.

“If no further net growth occurs, the sea ice maximum will be below 17mn square kilometres for the first time in the satellite record, and about 1mn square kilometres below the previous record low maximum of 1986,” said NSIDC. That year, Antarctic sea ice reached an annual maximum of just 17.986mn square kilometres on September 21.

The five low maximum sea ice extents for Antarctica include 1986, 2002, 2017, 1989 and 2022. High variability is typical of the sea ice maximum period, and further growth is likely from storms or high winds along the vast circumpolar sea ice edge.

Antarctica is losing ice mass (melting) at an average rate of about 150bn tonnes per year, and Greenland is losing about 270bn tpy, adding to sea level rise, says NASA.

The Antarctic ice had been thought to be relatively immune to climate change, says IFL Science, helping to keep the global temperature rise in check by reflecting unlight and cooling the oceans.

But now it seems that temperatures might rise faster and the sea level might increase even further than had been predicted, the new data suggest.