One study indicates that several points of no return can be quickly reached

Five possible break points. Global warming beyond 1.5°C, the most ambitious goal of the Paris Agreement, could have many causes. “critical points” Climatic conditions that would cause a catastrophic chain reaction, according to a study published on Friday, September 9 in the magazine Science.

According to the study, current temperatures, already high, threaten to trigger five of these points of failure, including those related to the ice sheets in Antarctica and Greenland, warns the study’s authors, who estimate that it’s not too late. an act. “For me, it would change the face of the world — literally, if I watched from space.”As ocean levels rise or forests are destroyed, explained Tim Linton, one of the study’s lead authors.

a “turning point” he is A critical threshold beyond which the system is reorganized, often brutally and/or irreversibly., as defined by the United Nations Panel of Climate Experts (IPCC). These are phenomena that independently and inevitably lead to further sequential consequences. The authors identify nine “critical points” major at the planetary level and seven at the regional level, making a total of 16. Of these, five can run with current temperatures, which have risen nearly 1.2°C on average since the pre-industrial era.

One of them relates to the ice cap in Antarctica and Greenland, and Participation, over hundreds of years, in a sea level rise of 10 metres. may cause another Sudden thaw of permafrost, which It would release massive amounts of greenhouse gases and profoundly alter landscapes in Russia, Canada and Scandinavia. The study also mentions among these five turning points the cessation of the phenomenon of heat transfer in the Labrador Sea (in the Atlantic Ocean, between Labrador and Greenland) and the extinction of coral reefs.

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If preliminary analyzes estimate the release threshold of these tipping points in the 3–5 °C range of warming, advances in observations and climate modeling, as well as in reconstructions of past climates, have significantly lowered this assessment. The study was published in Science It is a synthesis of more than 200 scientific publications, performed in order to better predict the thresholds causing these breakpoints.