Flux continu

SpaceX, IA, marchés financiers… Pour Philippe Gijsels (BNPP Fortis), nous traversons actuellement une période sans précédent dans l'histoire économique et financière.

The Gulf Stream is part of the Atlantic Meridional Overturning Circulation (AMOC). The AMOC is a tipping element and may collapse under changing forcing. However, the role of the Gulf Stream in such a tipping event is unknown. Here, we investigate the link between the AMOC and Gulf Stream using a high-resolution (0. 1°) stand-alone ocean simulation, in which the AMOC collapses under a slowly-increasing freshwater forcing. AMOC weakening gradually shifts the Gulf Stream near Cape Hatteras northward, followed by an abrupt northward displacement of 219 km within 2 years. This rapid shift occurs a few decades before the simulated AMOC collapse. Satellite altimetry shows a significant (1993–2024, p < 0.05) northward Gulf Stream trend near Cape Hatteras, which is also confirmed in subsurface temperature observations (1965–2024, p < 0.01). These findings provide indirect evidence for present-day AMOC weakening and demonstrate that abrupt Gulf Stream shifts can serve as early warning indicator for AMOC tipping.

Several, more recent global warming projections in the coupled model intercomparison project 6 contain extensions beyond year 2100–2300/2500. The Atlantic meridional overturning circulation (AMOC) in these projections shows transitions to extremely weak overturning below the surface mixed layer (<6 Sv; 1 Sv = 106 m3 s−1) in all models forced by a high-emission (SSP585) scenario and sometimes also forced by an intermediate- (SSP245) and low-emission (SSP126) scenario. These extremely weak overturning states are characterised by a shallow maximum overturning at depths less than 200 m and a shutdown of the circulation associated with North Atlantic deep water formation. Northward Atlantic heat transport at 26°N decreases to 20%–40% of the current observed value. Heat release to the atmosphere north of 45°N weakens to less than 20% of its present-day value and in some models completely vanishes, leading to strong cooling in the subpolar North Atlantic and Northwest Europe. In all cases, these transitions to a

Tué par balles sur le campus d’une université mercredi, Charlie Kirk laisse derrière lui Turning Point USA, l’organisation qu’il a fondée en 2012 et transformée en machine de guerre idéologique pour séduire la jeunesse conservatrice américaine. Décryptage.

False claims obstructing climate action, say researchers, amid calls for climate lies to be criminalised

The Atlantic Meridional Overturning Circulation (AMOC), vital for northwards heat transport in the Atlantic Ocean, is projected to weaken owing to global warming1, with significant global climate impacts2. However, the extent of AMOC weakening is uncertain with wide variation a …

Tougher laws said to be inspiring clandestine attacks on the ‘property and machinery’ of the fossil fuel economy

In 1919, at the height of a global crisis that resulted from the turmoil of the Russian Revolution, the devastation of the first world war, and the collapse of Europe’s great continental empires, Irish writer William Butler Yeats penned his famed warning to humanity, mourning the end of the old world: “Things fall apart; the centre cannot hold / Mere anarchy is loosed upon the world.”

On why collapse could be much closer than predicted: what happens when the Atlantic Ocean’s heart stops beating?

The idea that the AMOC is headed to collapse is very controversial, but it is clearly weakening. If the circulation did collapse, the consequences on both sides of the Atlantic Ocean would be immense—including large changes in temperature and a spike in weather-related disasters.