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Climate models show considerable discrepancies in their future projections around the Atlantic, mainly due to uncertainties in the fate of the Atlantic Meridional Overturning Circulation (AMOC). Climate models suggest a reduction in AMOC strength of 32 ± 37% by 2100 (90% probability, Shared Socioeconomic Pathways 2-4.5 scenario, Coupled Model Intercomparison Project Phase 6). To refine this estimate and reduce its uncertainty, we use four different observational constraint methods. The best one, which provides the lowest leave-one-out error, integrates a large set of observable variables using ridge-regularized linear regression—a method unusual in climate science. It gives an estimate of the AMOC slowdown of 51 ± 8% (90% probability), i.e., a weakening ∼ 60% stronger than suggested by the multimodel mean. This refinement mainly results from correcting a bias in South Atlantic surface salinity, consistent with recent studies emphasizing its role in the proximity to an AMOC tipping point. This more substantial

Les lois de puissance s’appliquent aussi aux catastrophes climatiques. L’économie classique du climat et les modèles utilisés sont inadaptés. Les approches robustes permettent de combiner prudence pour éviter la catastrophe, et raisonnement économique.

Continued global heating could set irreversible course by triggering climate tipping points, but most people unaware

Delegates made minimal headway on timetable for replacing oil and gas or on firm commitments to reducing carbon emissions

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

There is rising concern that several parts of the Earth system may abruptly transition to alternative stable states in response to anthropogenic climate and land-use change. Key candidates of such tipping elements include the Greenland Ice Sheet, the Atlantic Meridional Overturning Circulation, the South American monsoon system and the Amazon rainforest. Owing to the complex dynamics and feedbacks between them via oceanic and atmospheric coupling, the levels of anthropogenic forcing at which transitions to alternative states can be expected remain uncertain. Here we demonstrate how such interactions can generate spurious signals and potentially mask genuine signs of destabilization. We further review and present observation-based evidence that the stability of these four tipping elements has declined in recent decades, suggesting that they have moved towards their critical thresholds, which may be crossed within the range of unmitigated anthropogenic warming. Our results call for better monitoring of these ti

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".

Economic assumptions about risks of the climate crisis are no longer relevant, says the communications expert Genevieve Guenther

The world has been too optimistic about the risk to humanity and planet – but devastation can still be avoided, says Timothy Lenton