The South pole is not immune to global warming: the temperature has increased 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 Monday.
Antarctica is marked by a variability of extreme climate, with great differences between the coasts and the interior of the continent, including the plateau of ice, where is the South pole.
Thus, the major part of west Antarctica and the antarctic peninsula has experienced a warming and a melting of the ice in the second half of the Twentieth century.
At the same time, on the contrary, the South pole has cooled down. At least until the 1980s, before that the trend is not reversed, as shown in the study published Monday in the journal Nature Climate Change.
With +0,61°C per decade, between 1989 and 2018, the temperature recorded on the base Amundsen–Scott at the South pole geographic, has increased three times more than the global average, say the researchers.
A result that has surprised. “It was believed that this part of the Antarctica high plateau isolated – would be safe from global warming. We discovered that this was no longer the case”, told AFP one of the authors, Kyle Clem, of the University of Victoria in Wellington.
But the global warming linked to emissions of greenhouse gases produced by human activities is not necessarily responsible, in any case not alone.
The “mechanism-first” that has led to this rapid warming of the South pole, where the temperature is always largely below 0°C (annual average around -49°C), is related to a warming in the tropical zone of the western pacific ocean. This resulted in a decrease of the atmospheric pressure in the Weddell sea and pushed the hot air towards the South pole, according to the study.
Even if the climate models do not show that he is “not impossible” that the rate of warming of 0.61°C per decade occurs naturally, it is “very unlikely,” said Kyle Clem, which indicates that the +1.8°C in 30 years at the South pole, these models attribute +1°C climate change caused by man.
“The real message […] is that no place is safe from climate change”, commented Sharon Stammerjohn, and Ted Scambos, of the University of Colorado, who are primarily concerned about for the coasts of the Antarctic and the greenland ice sheet.
“The effects of climate change are felt for a long time,” and that the continent’s contribution to global warming and the increase in the level of the sea could become “catastrophic,” they write.
The melting of the ice caps of Greenland and Antarctica is already the main source of the increase in the level of the oceans.
But the future of coastal regions and their millions of inhabitants depend largely on the enormous mass of ice covering west Antarctica.