Heat stroke on Antarctica: the temperature has risen at a crazy rate over the last thirty years. Explanations.
The South Pole is no longer immune to warming: the temperature there has risen three times faster than the global average over the past 30 years, due to natural phenomena “probably intensified” by climate change, according to a study published on Monday. Antarctica is marked by extreme climatic variability, with strong differences between the coasts and the interior of the continent, especially the icy plateau where the South Pole is located.
For example, most of West Antarctica and the Antarctic Peninsula experienced ice warming and melting in the second half of the 20th century. At the same time, on the contrary, the South Pole has cooled. At least until the 1980s, before the trend reversed, as the study, published Monday in the journal Nature Climate Change, shows.
Between 1989 and 2018, the temperature recorded at the Amundsen-Scott base at the geographic South Pole increased more than three times as much as the global average, the researchers said, at 0.61 degrees Celsius. A result that surprised them. “It was believed that this part of Antarctica — the isolated high plateau — would be safe from warming. We found that this was no longer the case,” one of the authors, Kyle Clem of Victoria University in Wellington.
But global warming linked to greenhouse gas emissions from human activities is not necessarily responsible, at least not alone. The “first mechanism” that led to this rapid warming of the South Pole, where the temperature is constantly well below 0C (annual average around -49C), is linked to warming in the tropical zone of the Western Pacific Ocean. This led to a drop in atmospheric pressure in the Weddell Sea and pushed warm air towards the South Pole, according to the study.
Antarctic coasts and the ice sheet at risk
Even if climate models show that it is “not impossible” that the rate of warming of 0.61 degrees Celsius per decade has occurred naturally, it is “very unlikely”, insisted Kyle Clem, who points out that over 30 years at the South Pole, these models attribute ‘1 ‘C to climate change caused by man.
“The real message … is that no place is immune to climate change,” said Sharon Stammerjohn and Ted Scambos of the University of Colorado, who are particularly concerned about the Antarctic coast and the ice sheet. “The effects of climate change have been felt for a long time,” and the continent’s contribution to warming and sea level rise could become “catastrophic,” they continued.
Melting ice caps in Greenland and Antarctica are already the main source of rising sea levels. But the future of coastal regions and their millions of inhabitants depends mainly on the huge mass of ice covering West Antarctica.