➔ 
filtre:
tipping
2025
Les récifs coralliens ont franchi un "point de basculement" climatique
It looked like snow under water: white, endless, and still. The reef, my friend Lisbeth said, was “the most beautiful thing she’d ever seen.” For a second, I almost agreed. Then, I stared at it for a long time before replying. She wasn’t wrong about its beauty. But she was also showing me death. Bleached coral isn’t a kind of coral. It’s the moment just after the funeral, what’s left when life is gone. A cathedral of bone-white skeletons stretching over an empire of calcified death. From above, it glows like marble. Up close, it’s a graveyard.
GLOBAL TIPPING POINTS REPORT 2025 - Summary
GLOBAL TIPPING POINTS REPORT - 2025
Avec l'agonie des récifs coralliens, le premier point de basculement climatique a été franchi. C'est ce qu'annoncent lundi 160 scientifiques dans le Global Tipping Points Report.
L’humanité a trop déstabilisé le climat, au point de l’avoir rapproché de « points de bascule » au potentiel cataclysmique, alertent 160 scientifiques dans un nouveau rapport.
Unless global heating is reduced to 1.2C ‘as fast as possible’, warm water coral reefs will not remain ‘at any meaningful scale’, a report by 160 scientists from 23 countries warns
Four key parts of the Earth’s climate system are destabilising, according to a new study with contributions from the Potsdam Institute for Climate Impact Research (PIK). Researchers analysed the interconnections of four major tipping elements: the Greenland ice sheet, the Atlantic meridional overturning circulation (AMOC), the Amazon rainforest and the South American monsoon system. All four show signs of diminished resilience, raising the risk of abrupt and potentially irreversible changes.
The Atlantic meridional overturning circulation (AMOC) is an important tipping element in the climate system. There is a large uncertainty whether the AMOC will start to collapse during the century under future climate change, as this requires long climate model simulations which are not always available. Here, we analyze targeted climate model simulations done with the Community Earth System Model (CESM) with the aim to develop a physics-based indicator for the onset of an AMOC tipping event. This indicator is diagnosed from the surface buoyancy fluxes over the North Atlantic Ocean and is performing successfully under quasi-equilibrium freshwater forcing, freshwater pulse forcing, climate change scenarios, and for different climate models. An analysis consisting of 25 different climate models shows that the AMOC could begin to collapse by 2063 (from 2026 to 2095, to percentiles) under an intermediate emission scenario (SSP2-4.5), or by 2055 (from 2023 to 2076, to percentiles) under a high-end emission scenar
Les vagues de chaleur marine pourraient avoir conduit les océans de la planète à un point de basculement critique. Les scientifiques craignent que le réchauffement prolongé des océans ne devienne la "nouvelle normalité".
