Justice & Paix

Les grandes puissances déploient des initiatives de connectivité qui redessinent la carte du monde. La Chine avec ses Nouvelles Routes de la soie, l’Union européenne et son Global Gateway, les États-Unis et le G7 à travers le Build Back Better World ou B3W/PGII… Tous ces projets traduisent une même ambition : organiser, sécuriser et contrôler l’internationalisation de l’économie, plutôt que la subir.

Emerging climate extremes should draw public attention to human-caused climate change. We expect unusual sea surface temperature (SST) and global warming the rest of this year to make 2026 hotter than 2024, despite 2024 being a peak El Nino year, while 2026 is only the lead-in year of an emerging El Nino. Beware the “surprise” record high being blamed on an extreme El Nino on top of global warming otherwise consistent with IPCC estimates. Instead, record warmth provides additional evidence of high climate sensitivity and increased net climate forcing in the past decade. These two factors are driving an unusual increase in global SSTs with major consequences. If you bear with our discussion to the end, you will find some possible good news. Figures in this post are continually updated on our website.[2] We are now on Substack[3].

Le monde entier subit des canicules sans précédent. Un dôme de chaleur couvre le Nord de l’Amérique du Nord, apporte des températures de 46°C , et cette canicule a permis d’immenses feux de forêt au Canada dont la fumée se répand sur la Planète.

Scientists know how to alter our atmosphere to try and fix climate change, but doing so could bring other potential unintended impacts

Projections of near-term climate change are a potential research tool. However, for that tool to be most useful, the physical basis for a prediction must be made clear. The basis for our projection of record 2026 global temperature is high climate sensitivity, with its implication that aerosol cooling was still increasing during the period 1970-2005. One consequence, global sea surface warming, already has important effects. Causes of climate change must be understood for policy purposes. Figures in this post and our recent papers are continually updated on our website.[1] We are also now on Substack[2].

Vagues de chaleur marines en hausse, fonte du budget carbone... Ces indicateurs qui explosent témoignent du rythme sans précédent atteint par le réchauffement planétaire, estiment 73 chercheurs dans un rapport publié le 11 juin.

Climate change is causing measurable harm globally1,2. Political and legal efforts seek to link these damages with specific emissions, including in discussions of loss and damage (L&D)3,4; however, no quantitative definition of L&D exists5,6, nor is there a framework to link past and future emissions from specific sources to monetized, location-specific damages. Here we develop such a framework, which is integrated with recent efforts to estimate the social cost of carbon7. Using empirical estimates of the non-linear relationship between temperature and aggregate economic output, we show that future damages from past emissions—one component of L&D—are at least an order of magnitude larger than historical damages from the same emissions. For instance, one tonne of CO2 emitted in 1990 caused US$180 in discounted global damages by 2020 ($40–530) and will cause an additional $1,840 through 2100 ($500–5,700). Thus, settling debts for past damages will not settle debts for past emissions. In other illustrative esti

Welcome to the Global Climate Highlights 2025 report, compiled by the Copernicus Climate Change Service (C3S). The Global Climate Highlights 2025 report provides authoritative climate data and concise insight on a global scale about 2025's climate conditions, covering surface and sea surface temperature, heat stress, sea ice extent in the Arctic and Antarctic, among others.

Le climat a -et aura de plus en plus- des impacts bien réels pour les habitants partout sur le territoire français. Si agir au niveau global est essentiel, les enjeux climatiques doivent aussi impérativement être pensés et faire l’objet d’initiatives au niveau local. En fins connaisseurs de leurs territoires, les maires sont des acteurs incontournables de l’adaptation et – faut-il le rappeler – de l’accompagnement à la transition énergétique et écologique.

Les modèles climatiques qui calculent le climat futur sont basés sur l’Histoire de la Terre. La géologie nous a apporté des renseignements sur les glaces, les océans, et les animaux et végétaux du passé. L’air ancien a laissé des traces dans des bulles congelées dans les profondeurs des glaciers polaires et dans les coquilles de minuscules animaux marins. Un élément du passé restait inconnu. Les nuages étaient difficiles à reconstituer. Aujourd’hui, les observations satellites montrent que la couverture nuageuse est en train de changer, et ces changements amplifient déjà le réchauffement climatique.

22 of the planet’s 34 vital signs are at record levels, with many of them continuing to trend sharply in the wrong direction. This is the message of the sixth issue of the annual “State of the climate” report. The report was prepared by an international coalition with contribution from the Potsdam Institute for Climate Impact Research (PIK) and led by Oregon State University scientists. Published today in BioScience, it cites global data from the Intergovernmental Panel on Climate Change (IPCC) in proposing “high-impact” strategies.

Pour appréhender l’ampleur de la destruction du climat, le chercheur Gaspard Lemaire plaide pour l’utilisation du concept d’« atrocité climatique ». Un terme qui permettrait de mieux pointer les responsabilités des États.

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.

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.

Identifying the socio-economic drivers behind greenhouse gas emissions is crucial to design mitigation policies. Existing studies predominantly analyze short-term CO2 emissions from fossil fuels, neglecting long-term trends and other GHGs. We examine the drivers of all greenhouse gas emissions between 1820–2050 globally and regionally. The Industrial Revolution triggered sustained emission growth worldwide—initially through fossil fuel use in industrialized economies but also as a result of agricultural expansion and deforestation. Globally, technological innovation and energy mix changes prevented 31 (17–42) Gt CO2e emissions over two centuries. Yet these gains were dwarfed by 81 (64–97) Gt CO2e resulting from economic expansion, with regional drivers diverging sharply: population growth dominated in Latin America and Sub-Saharan Africa, while rising affluence was the main driver of emissions elsewhere. Meeting climate targets now requires the carbon intensity of GDP to decline 3 times faster than the global

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.

An international group of researchers has produced a third update to key indicators of the state of the climate system set out in the IPCC AR6 assessment, building on previous editions in 2023 and 2024. Forster et al. (2025) assess emissions, concentrations, temperatures, energy transfers, radiation balances, and the role of human activity and conclude that, while natural climate variability also played a role, the record observed temperatures in 2024 were dominated by human activity and the remaining carbon budget for 1.5° C is smaller than ever.

Recent simulations using the Community Earth System Model (CESM) indicate that a tipping event of the Atlantic Meridional Overturning Circulation (AMOC) would cause Europe to cool by several degrees. This AMOC tipping event was found under constant pre-industrial greenhouse gas forcing, while global warming likely limits this AMOC-induced cooling response. Here, we quantify the European temperature responses under different AMOC regimes and climate change scenarios. A strongly reduced AMOC state and intermediate global warming (C, Representative Concentration Pathway 4.5) has a profound cooling effect on Northwestern Europe with more intense cold extremes. The largest temperature responses are found during the winter months and these responses are strongly influenced by the North Atlantic sea-ice extent. Enhanced North Atlantic storm track activity under an AMOC collapse results in substantially larger day-to-day temperature fluctuations. We conclude that the (far) future European temperatures are dependent o

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.

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.