Flux continu

The Antarctic Circumpolar Current (ACC) is the world's strongest ocean current and plays a disproportionate role in the climate system due to its role as a conduit for major ocean basins. This current system is linked to the ocean's vertical overturning circulation, and is thus pivotal to the uptake of heat and CO2 in the ocean. The strength of the ACC has varied substantially across warm and cold climates in Earth's past, but the exact dynamical drivers of this change remain elusive. This is in part because ocean models have historically been unable to adequately resolve the small-scale processes that control current strength. Here, we assess a global ocean model simulation which resolves such processes to diagnose the impact of changing thermal, haline and wind conditions on the strength of the ACC. Our results show that, by 2050, the strength of the ACC declines by ∼20% for a high-emissions scenario. This decline is driven by meltwater from ice shelves around Antarctica, which is exported to lower latit

L’Organisation Météorologique Mondiale (OMM) publie ses prévisions climatiques pour les cinq prochaines années, 2025-2029. Selon l’OMM, les températures de la terre oscilleront entre +1.2°C et + 1.9°C, ce qui nous amène très près de 2°C de réchauffement en 2030 (OMM). Nous serons alors proches du climat annoncé pour la France à 4°C.

Critical minerals, which are essential for a range of energy technologies and for the broader economy, have become a major focus in global policy and trade discussions. Price volatility, supply chain bottlenecks and geopolitical concerns make the regular monitoring of their supply and demand extremely vital.

Earth’s albedo (reflectivity) declined over the 25 years of precise satellite data, with the decline so large that this change must be mainly reduced reflection of sunlight by clouds. Part of the cloud change is caused by reduction of human-made atmospheric aerosols, which act as condensation nuclei for cloud formation, but most of the cloud change is cloud feedback that occurs with global warming. The observed albedo change proves that clouds provide a large, amplifying, climate feedback. This large cloud feedback confirms high climate sensitivity, consistent with paleoclimate data and with the rate of global warming in the past century.

Nouveau "TALK" sur LIMIT avec Matthieu Auzanneau,, auteur et directeur du think tank de la transition énergétique The Shift Project nous abordons l’inexorable épuisement des ressources fossiles et ses conséquences géopolitiques (Golfe Persique, Irak, Ukraine) La dépendance de l’Europe au pétrole et au gaz. Les grands moments historiques du pétrole (pic de 1970, Mer du Nord, boom du shale aux USA) Les premiers accords climatiques (Protocole de Kyoto) et la croissance paradoxale de la consommation de gaz L’analogie du corps humain pour montrer que l’énergie est l’« organe vital » de nos sociétés Les pistes de sortie de la « marriage pétrolier » : sobriété organisée, souveraineté industrielle, transition vers les renouvelables Et un appel à l’élaboration d’un plan clair et collectif pour réduire la dépendance aux énergies carbonées « Decarbonons la France ! »

When it comes to our understanding of the unfolding global crisis, each of us seems to fit somewhere along a continuum of awareness that can be roughly divided into five stages:

Acute global food insecurity rose for the sixth year in a row in 2024, according to the 2025 Global Report on Food Crises (GRFC), a collaborative effort coordinated by the Food Security Information Network. The report shows that climate extremes, conflict, forced displacement and economic shocks continue to drive malnutrition and food insecurity around the world, with disastrous impacts on those living in many of the most vulnerable regions in the world.

Societies increasingly rely on scientists to guide decisions in times of uncertainty, from pandemic outbreaks to the rise of artificial intelligence. Addressing climate change is no different. For governments wanting to introduce ambitious climate policies, public trust in climate scientists is pivotal, because it can determine whether voters support or resist those efforts.

Small particulate matter (PM2.5) in air pollution raises the risks of respiratory problems, cardiovascular disease, and even cognitive decline. Heat waves, which are occurring more often with climate change, can cause heatstroke and exacerbate conditions such as asthma and diabetes. When heat and pollution coincide, they can create a deadly combination.

For around 2,000 years, global sea levels varied little. That changed in the 20th century. They started rising and have not stopped since — and the pace is accelerating. Scientists are scrambling to understand what this means for the future just as President Trump strips back agencies tasked with monitoring the oceans.