When Greenland melts in September
It's September, and Greenland is still melting. This is the worried warning issued at the beginning of the month by the American glaciologist Jason Box, from his observation post on the ice floe, as the rain began to fall.
Normally, summer ends there as early as August, and September is when the winter ice begins to form again. Not this time: From September 3, several consecutive days of rain accelerated the melting of part of the ice sheet that covers this island-continent. A melting which, in the end, was measured in tens of billions of tons of ice: it would be the most important melting to have occurred in September, for 40 years that such data have been collected. And some weather stations recorded, between September 3 and September 6, their highest temperatures, not of September, but of the year.
The immediate culprit: a hot air current from the south, over Baffin Bay and West Greenland.
Extent of melting (in % area). In blue: median 1981-2010, In red: 2022
This is obviously not the first time in recent history that glaciologists are worried about seeing new records appear. But the finding this year comes two weeks after the publication of a study on “tipping points” — those thresholds beyond which some of the Earth's systems are at risk of collapse. One of the systems identified in this study, published in the journal Science, is the Greenland ice cap: at some point, the researchers write, presumably when the increase in the average temperature of our planet will have exceeded the threshold at 1.5◦ Celsius, the melting of this ice cap will become irreversible. At the rate things are going, this threshold could be reached shortly after 2030.
It should be remembered that when we talk about an increase in the average temperature of our planet of 1.5 degrees since During the industrial era, in Greenland on the other hand, the increase is more like 3 degrees. And the early September anomaly ranged between 10 and 17 degrees above the average for the years 1979 to 2000, according to the University of Maine's Climate Reanalyzer group.