While a global day of youth action on climate change is being held this Friday, March 25, around the world, an event came to remind us of the reality of climate change: record temperatures for the season were recorded simultaneously at the two poles at the end of last week. On Thursday, March 17 and Friday, March 18, temperatures exceeded seasonal norms by more than 40 ° C in the Antarctic, and variations of more than 30 ° C were also observed in the Arctic. This visualization from the Institute on Climate Change at the University of Maine (USA) shows the extent of these two simultaneous waves of gentleness at both poles.
[Graphic from https://t.co/53SpSZcJCa] pic.twitter.com/qHU0u9HLt0
—Zack Labe (@ZLabe) March 19, 2022
Supports infographics, france info comes back to these unusual heat waves and what they say about the state of the polar climate. While the records recorded in Antarctica surprised by their magnitude and suddenness, the wave of mildness at the North Pole is, on the contrary, the syndrome of a warming that has been going on for many years.
In Antarctica, an unprecedented phenomenon of concern
“This is unheard of! We are 40 ° C above seasonal norms, but also almost 15 ° C above previous records for the seasonsays Gaetan Heymesforecast engineer at Météo France. Although the climate in Antarctica is more changeable than in France, the temperature difference can be compared to a temperature of 35 ° C in March in Paris“explains the man who spent several weeks on a mission to the South Pole.
Temperatures recorded at the French-Italian base Concordia, located in Antarctica, is really impressive. The following graph is produced using data provided by the Observatoire de la Côte d’Azur and based on the model of an infographic made by the latter. It allows you to realize it that -12 ° C measured on March 18 is a record high for at least eight years and that this peak comes at a time of year when temperatures are generally falling. Usually they are around -55 ° C.
Tristan Guillot was in the front row to observe this record. At the Côte d’Azur Observatory, where he is CNRS research leader, scientists receive live images from the Concordia base and operate a telescope on site. But on March 17, an event occurred to disrupt the operation of the unit: “We received a message from someone who was overwintering on the spot informing us of abnormal heating of the camera box on our telescope, heated to withstand outdoor temperatures of -80 ° C. We then noticed that the temperature in the camera box exceeded 40 ° C! We have been forced to stop our telescopic acquisitions while waiting for more normal conditions. “
If this temperature particularly surprised scientists, approxis because it intervenes in a region that did not appear to be in a warming dynamic: “In Antarctica, an increase in temperatures was observed in the western part, but not in the eastern part of the continent, while it is precisely in this area that the heat wave was recorded.details Gaétan Heymes. As this event is unique and is not part of a long-term dynamic, it is difficult to attribute it with certainty to climate change today. But it is very likely that the connection in retrospect will be demonstrated“, confirmshe.
A warning about the situation in Antarctica had already been registered last month. In 25 February, in the middle of the Australian summer, the surface of the pakis around the white continent had reached its historic low for more than forty years, as measured. But again, since the phenomenon is not long-lasting at the moment, it is difficult to make a direct connection with climate change.
In the Arctic, a warming observed for several years
At the same time, even though it was immersed in the boreal winter, the Arctic also recorded very high temperatures, more than 30 ° C above normal for the season. But unlike the South Pole, rising temperatures in the Arctic are part of a sharp warming of the region, which has been observed for several years.
“The heat wave at the North Pole is slightly smaller than at the South Pole, but above all it is less surprising because the rapid warming of the North Pole is a well-known phenomenon. “ Explain Gaetan Heymes. In fact, the Arctic is warming much faster than the rest of the globe: onWhile the global temperature has risen by about 1 ° C compared to the reference period 1950-1980, this rise reaches almost 3 ° C for the Arctic.
This accelerated warming is the result of a vicious circle in which the North Pole finds itself: “IRising temperatures melt the ice, and since ice usually reflects the sun’s rays, its disappearance leads to greater absorption of this solar heat and therefore an increase in temperatures.Explains Joël Guiot, Research Director at the European Center for Research and Education in Environmental Geosciences.
The melting of sea ice (pakis) in summer in the North Pole region has been very marked in the last fifteen years: while the minimum sea ice surface (which reached the end of the summer) never fell below 6 million square kilometers before the end of the 1990s, this annual minimum surface area is barely more than 4.5 million square kilometers on average since the mid-2000s . The fifteen lowest levels recorded since the early 1980s correspond to the last fifteen years.
According to Patricia Espinosa, Executive Secretary of the United Nations Framework Convention on Climate Change (UNFCCC), summers in the Arctic Ocean could be ice-free as early as 2030 if CO2 emissions continue at current rates.