The Antarctic sea ice reached, in July, its smallest area ever recorded for a month of July in forty-four years of satellite surveys, alerted the European service on climate change Copernicus, Monday August 8, confirming a year alarming.
Since 1979, scientists have had very precise measurements of the extent of the North and South Pole sea ice thanks to satellites. Sea ice is the ice that floats on the ocean; its melting therefore does not raise sea levels, but it indirectly contributes to global warming, as the open ocean absorbs more heat.
The normal cycle of sea ice, in the Arctic as in Antarctica, is that it melts in summer and re-forms in winter. In the long term, the melting is rapid in Greenland and the Arctic, but conversely, in the Antarctic, the trend was modestly upward, despite significant annual and regional variations, without us understanding the exact phenomenon.
1.1 million square kilometers less
Antarctic sea ice had only reformed in July, which is winter in the southern hemisphere, over an average of 15.3 million square kilometers, or 1.1 million square kilometers less (−7%) than the average for that month between 1991 and 2020, Copernicus (C3S) scientists found.
At the end of the austral summer, in February, the sea ice had shrunk to its historic low, panicking scientists. It was 30% smaller than the three-decade average between 1981 and 2010. Since February, it had remained below seasonal averages, according to C3S. And, in June already, it had reached its historic low for the month.
In the Arctic, sea ice extent was 4% below average in July, according to Copernicus, the twelfth lowest extent on record for July.
Illustrating the imperfect understanding of the warming phenomenon in Antarctica, Copernicus recalls that the sea ice there was, conversely, above average a year ago, in July 2021.
2022 is a year of climate records in the world. July was one of the three hottest months ever recorded in the world, according to the World Meteorological Organization (WMO), a specialized agency of the United Nations based in Geneva.