Articles 2020

Les sanctions occidentales poussent la Russie à emprunter des routes alternatives et à exploiter un « marché gris » pour ses approvisionnements. Une nouvelle géographie des échanges se dessine-t-elle ? Est-elle durablement viable ?

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.

De nombreuses publications indiquent que l’Union européenne va bientôt scanner tous les contenus échangés sur les plateformes numériques. À travers un projet de directive européenne surnommé Chat Control, les citoyens européens seraient exposés à une surveillance de masse. L’initiative vise à lutter contre la pédocriminalité en ligne mais elle est contestée et suscite de vifs débats car sa mise en pratique implique des risques de dérives. La version actuelle du projet ne vise cependant pas toutes les conversations et fichiers mais uniquement les échanges d’images. Des garde-fous sont également prévus dans le projet actuel, qui pourrait encore évoluer.

Predictably, soon, most young people will reject extremist views. This will be none too soon because it is the essential step leading to global political leadership that appreciates the threat posed by climate’s delayed response to human-made changes of Earth’s atmosphere. Then the annual fraud of goals for future “net zero” emissions announced at United Nations COP (Conference of Parties) meetings might be replaced by realistic climate policies. It is important, by that time, that we have better knowledge of the degree and rate at which human-made forcing of the climate system must be decreased to avoid irreversible, unacceptable consequences.

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

The vast ice of Antarctica has long seemed impregnable. But sudden changes are arriving – from shrinking sea ice to melting ice sheets and slowing ocean currents.

2024 was the hottest year on record [1], with global temperatures exceeding 1.5 °C above preindustrial climate conditions for the first time and records broken across large parts of Earth’s surface. Among the widespread impacts of exceptional heat, rising food prices are beginning to play a prominent role in public perception, now the second most frequently cited impact of climate change experienced globally, following only extreme heat itself [2]. Recent econometric analysis confirms that abnormally high temperatures directly cause higher food prices, as impacts on agricultural production [3] translate into supply shortages and food price inflation [4, 5]. These analyses track changes in overall price aggregates which are typically slow-moving, but specific food goods can also experience much stronger short-term price spikes in response to extreme heat.

In a rapidly changing climate, evidence-based decision-making benefits from up-to-date and timely information. Here we compile monitoring datasets (published at https://doi.org/10.5281/zenodo.15639576; Smith et al., 2025a) to produce updated estimates for key indicators of the state of the climate system: net emissions of greenhouse gases and short-lived climate forcers, greenhouse gas concentrations, radiative forcing, the Earth's energy imbalance, surface temperature changes, warming attributed to human activities, the remaining carbon budget, and estimates of global temperature extremes. This year, we additionally include indicators for sea-level rise and land precipitation change. We follow methods as closely as possible to those used in the IPCC Sixth Assessment Report (AR6) Working Group One report.

Dans le cadre d’une étude récente, des économistes européens ont simulé un arrêt des échanges alimentaires mondiaux. Selon les résultats, un seul pays brillant par son autosuffisance devrait survivre aisément à l’arrêt des échanges alimentaires.

La Belgique a assuré l'Ukraine de son soutien après l'altercation, vendredi soir à la Maison Blanche, entre le président des États-Unis Donald Trump et le président ukrainien Volodymyr Zelensky.

Alors qu’ils doivent signer dans le Bureau ovale un accord sur les minerais rares, les échanges entre les présidents américain et ukrainien ont dégénéré.

Le président ukrainien s’est dit prêt, mardi lors d’un entretien au « Guardian », à « un échange » de territoires avec le Kremlin, dans le cadre d’éventuelles négociations de paix sous l’égide des États-Unis.

Heatwaves can lead to considerable impacts on societal and natural systems. Accurate simulation of their response to warming is important for adaptation to potential climate futures. Here, we quantify changes of extreme temperatures worldwide over recent decades. We find an emergence of hotspots where the hottest temperatures are warming significantly faster than more moderate temperatures. In these regions, trends are largely underestimated in climate model simulations. Globally aggregated, we find that models struggle with both ends of the trend distribution, with positive trends being underestimated most, while moderate trends are well reproduced. Our findings highlight the need to better understand and model extreme heat and to rapidly mitigate greenhouse gas emissions to avoid further harm.

Le Hezbollah et son allié Amal ont annoncé mercredi soir huit morts dans leurs rangs, parmi lesquels des secouristes, dans des frappes israéliennes dans le sud du Liban portant à 16 le nombre de victimes d'une journée d'échanges de tirs transfrontaliers.

Après les attaques répétées de bateaux dans la mer Rouge par les rebelles houthis, les compagnies maritimes évitent l'un des principaux corridors du commerce mondial, ce qui devrait perturber les échanges, avec des retards et des surcoûts. Que s'est-il passé?Ces dernières semaines, des rebelles houthis du Yémen, proches de l'Iran, ont multiplié les attaques près du détroit stratégique de Bab al-Mandeb, qui sépare la péninsule arabique de l'Afrique.

Les Etats-Unis et le Japon ont signé mardi un accord visant à renforcer "les chaînes d'approvisionnement pour les minéraux critiques et les batteries pour véhicules électriques" et renforcer les échanges entre les deux pays concernant ces produits essentiels à la transition énergétique et jusqu'ici dominés par la Chine.

A recent paper suggested damaging climate tipping points could be closer than first thought.

Can we talk about it now? I mean the subject most of the media and most of the political class has been avoiding for so long. You know, the only subject that ultimately counts – the survival of life on Earth. Everyone knows, however carefully they avoid the topic, that, beside it, all the topics filling the front pages and obsessing the pundits are dust. Even the Times editors still publishing columns denying climate science know it. Even the candidates for the Tory leadership, ignoring or downplaying the issue, know it. Never has a silence been so loud or so resonant.

Food supply expert paints grim global picture hunger 05.23.2022 By Arvin Donley NEW YORK, NEW YORK, US — Global wheat inventories currently stand at about 10 weeks of global consumption, a food supply expert said during a special meeting of the United Nations Security Council on May 19. Sara Menker, chief executive officer of Gro Intelligence, an organization that gathers and analyzes global food and agricultural data, said she disputes official government agency estimates that put global wheat inventories at 33% of annual consumption, countering inventories are closer to 20%. “It is important to note that the lowest grain inventory levels the world has ever seen are now occurring while access to fertilizers is highly constrained, and drought in wheat growing regions around the world is the most extreme it’s been in over 20 years,” Menker said. “Similar inventory concerns also apply to corn and other grains. Government estimates are not adding up.” Menker told the security council that while much of the blame

The Gulf Stream has weakened substantially in the past decades, as revealed by the latest data and new studies. Weather in the United States and Europe depends strongly on this ocean current, so it’s important we understand the ongoing changes and what they mean for our weather now and in the near future.