Les Formats courts de l’Observatoire

Neuf communes belges font partie des villes lauréates du programme international "Youth Climate Action Fund" de Bloomberg Philanthropies. Chacune d’elles recevra 34.000 euros pour soutenir des jeunes de 15 à 24 ans dans la mise en place et la réalisation, à l’échelle locale, de projets concrets liés au climat et au développement durable.

Exclusive: As wildfires rage, Frank Elderson says more work needed to assess risk from collapse of ecosystem services

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].

Daily Sea Surface Temperature

Climate scientists warn of unprecedented Antarctic heatwave, with temperatures 20C above normal. Loss of sea ice threatens marine life and penguins.

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.

- Artificial intelligence could pose a "more urgent" threat to humanity than climate change, AI pioneer Geoffrey Hinton told Reuters in an interview on Friday. Geoffrey Hinton, widely known as one of the "godfathers of AI", recently announced he had quit Alphabet, opens new tab after a decade at the firm, saying he wanted to speak out on the risks of the technology without it affecting his former employer.

Global effort needed to limit effects of pollution, industrial fishing and climate crisis, World Ocean Assessment says

The Global Justice Report offers a hopeful bargain: tax extreme wealth and replace consumer excess with social and economic security for all

Les scénarios socio-économiques et les niveaux de réchauffement planétaire qui en résultent structurent la compréhension des chaines de causalité entre les émissions de gaz à effet de serre, le contrôle de la pollution atmosphérique, les changements d’usage des terres, la réponse du système Terre, les facteurs climatiques générateurs d’impacts, l’exposition, la vulnérabilité, les réponses d’adaptation, et les risques liés au climat.

Exclusive: Commission says alert would trigger coordinated international response that could help avoid millions dying. The climate crisis should be declared a global public health emergency by the World Health Organization, or millions more people will die unnecessarily, leading international experts have said. The independent pan-European commission on climate and health, which was convened by the WHO, concluded the climate crisis was such a worldwide threat to health that the WHO should declare it “a public health emergency of international concern” (Pheic).

Vous êtes formateur ou formatrice et souhaitez aborder le sujet des modèles climatiques lors d’une formation ? Modéliser le climat dans votre classe est une ressource de formation professionnelle conçue pour aider les enseignants à comprendre comment les modèles climatiques sont construits, comment ils fonctionnent et comment ils permettent d’analyser le changement climatique, les projections futures et les enjeux climatiques en milieu urbain.

Environment News: UNITED NATIONS: Vanuatu will renew its climate justice fight at the United Nations General Assembly with a draft resolution that was watered down afte.

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

Closed-door talks over the World Bank’s climate agenda have stalled, as the US pushes to scrap green targets and expand support for fossil fuels

The critical Atlantic current system appears significantly more likely to collapse than previously thought after new research found that climate models predicting the biggest slowdown are the most realistic. Scientists called the new finding “very concerning” as a collapse would have catastrophic consequences for Europe, Africa and the Americas.

A team including scientists, Indigenous people and conservationists point to the ecosystem connecting Yellowstone and the Yukon as an example of a region where humans and nature are flourishing together.

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

By the end of this century, parts of Africa could face heatwaves for 250-300 days a year, which will make it difficult for people to survive.

Climate change is making it challenging to identify future host cities.

Climate change could lead to half a million more deaths from malaria in Africa over the next 25 years, according to new research.

As climate and geopolitics shocks bite, countries are rebuilding food buffers. The UK clings to neoliberal ideas while households pay the price

The datasets used to diagnose the modern history of the planet’s climate — and to proclaim that the world is now very near to 1.5 degrees Celsius (2.7 degrees Fahrenheit) of warming — typically begin with the year 1850. The new one goes all the way back to 1781. This extended time frame matters because greenhouse gases in the atmosphere increased 2.5 percent between 1750 and 1850, enough to have caused some warming that the data hasn’t accounted for.

Rob Hopkins has spent the past decades exploring one question: what if we could fall in love with the future? As co-founder of Transition Network and Transition Town Totnes, and author of four books, he travels the world helping communities cultivate imagination, longing and possibility. He believes that the transition we so urgently need depends on one thing above all: imagination.

James Hansen : « Ce à quoi nous assistons aujourd'hui, c'est à une réticence scientifique poussée...

I always say that models are not predictions; they are qualitative illustrations of what the future could be. But as the future gets closer to the present, models can start being seen as predictive tools. It is the weather/climate dichotomy, so aptly exploited to confuse matters by politically minded people in the discussion about climate. Right now, we are getting close to the point that we could forecast a collapse in the same way as we can forecast the trajectory of a tropical storm. So, you remember how “The Limits to Growth” generated a long term forecast in 1972. Here it is

A “pushing and triggering” mechanism has has driven the Arctic climate system to a new state, which will likely see consistently increased frequency and intensity of extreme events across the atmosphere, ocean and cryosphere this century.

We are an international group of researchers and practitioners interested in the emerging fields of post-growth and ecological macroeconomics. Our aim is to advance economic theory, methodology and policy in order to adequately address some of the biggest challenges of our time: climate change, rising inequality, and financial instability.

We make meaningful climate action faster and easier by mobilizing the global tech community to track greenhouse gas (GHG) emissions with unprecedented detail.

How does one talk about climate change when armed conflicts are spiralling out of control?

Conservative leader Kemi Badenoch has described her plan to “maximise extraction” of the UK’s oil and gas from the North Sea as a “common sense” energy policy. Politicians are using language like this increasingly often – calling themselves “pragmatic” on climate change and invoking “common sense”. It sounds reasonable, reassuring, and grownup – the opposite of “hysterical” campaigners or “unrealistic” targets.

Avant l’été, un site gouvernemental américain d’information sur le climat a été invisibilisé par l’administration Trump. Depuis, d’anciens employés fédéraux travaillent bénévolement pour ressusciter son contenu.

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

This article examines the technocentric bias that characterizes climate mitigation literature, focusing on the reports of the IPCC's Working Group III. This bias stems from structural features of the scientific field that prioritizes innovation, leading to the overrepresentation of technological solutions in climate research. Funding mechanisms further reinforce this tendency by incentivizing collaboration with industrial R&D, creating a self-reinforcing loop in which scientific authority and industrial interests converge. The IPCC's institutional positioning—as a policy-relevant yet politically cautious body—amplifies this dynamic by favoring allegedly “cost-effective” technological pathways that lack practical feasibility.

Passing 1.5ºC is now inevitable. Overshoot scenarios tell us that we can relatively safely pass this level but then bring temperatures back down again, but how realistic are they, and how safe?

Climate sensitivity is substantially higher than IPCC’s best estimate (3°C for doubled CO2), a conclusion we reach with greater than 99 percent confidence. We also show that global climate forcing by aerosols became stronger (increasingly negative) during 1970-2005, unlike IPCC’s best estimate of aerosol forcing. High confidence in these conclusions is based on a broad analysis approach. IPCC’s underestimates of climate sensitivity and aerosol cooling follow from their disproportionate emphasis on global climate modeling, an approach that will not yield timely, reliable, policy advice.

Farming seaweed, changing ocean chemistry, breeding corals and restoring mangroves could help fight climate change – if assessed and managed responsibly.

The constant deluge of bad news about rising global temperatures and their impacts can make it feel like the world is ending. Is it?

C’est une tendance qui ne faiblit pas sur les réseaux sociaux. Face à la crise écologique, des centaines de jeunes témoignent de leur pessimisme quant à notre capacité à redresser la barre : on les appelle les "climate doomers". Résultat d’une éco-anxiété grandissante, ce phénomène participe à freiner l’action climatique.

For decades, the surface of the polar Southern Ocean (south of 50°S) has been freshening—an expected response to a warming climate. This freshening enhanced upper-ocean stratification, reducing the upward transport of subsurface heat and possibly contributing to sea ice expansion. It also limited the formation of open-ocean polynyas. Using satellite observations, we reveal a marked increase in surface salinity across the circumpolar Southern Ocean since 2015. This shift has weakened upper-ocean stratification, coinciding with a dramatic decline in Antarctic sea ice coverage. Additionally, rising salinity facilitated the reemergence of the Maud Rise polynya in the Weddell Sea, a phenomenon last observed in the mid-1970s.

Real world measurements of how much extra heat the Earth is trapping are well beyond most climate models. That’s a real problem.

Les financements aux industries du pétrole et du gaz repartent de plus belle. Le rapport Banking on climate chaos, signé par huit ONG, estime à près de 900 milliards de dollars les financements octroyés en 2024 par 65 banques aux industriels du secteur, en augmentation de 23%. Le backlash contre la finance durable n’est pas étranger à ce nouvel appétit de la finance pour les hydrocarbures.

Mark Lynas has spent decades pushing for action on climate emissions but now says nuclear war is even greater threat Climate breakdown is usually held up as the biggest, most urgent threat humans pose to the future of the planet today. But what if there was another, greater, human-made threat that could snuff out not only human civilisation, but practically the entire biosphere, in the blink of an eye?

Despite mounting evidence of global warming’s costs, the Trump administration has made multiple moves to avoid tracking climate-related economics.

On 21 April 2019, I was on Waterloo Bridge in London with my younger siblings. Around us were planters full of flowers where there were once cars, and people singing. This was the spring iteration of Extinction Rebellion, when four bridges in London were held by protesters. My siblings, then 14, had been going out on school strike inspired by Greta Thunberg, and wanted to see her speak.

The Global Justice Project is a collective research initiative developed by the World Inequality Lab. Combining comparative historical data series from the World Inequality Database with global input-output tables, environmental accounts, labour force surveys and other sources, the project explores what a just distribution of socio-economic and environmental resources could look like at the global level from 2025 to 2100 – both between and within countries – in a way that is compatible with planetary boundaries. The project partly builds on the analysis and proposals set out in Thomas Piketty’s Brief History of Equality, extending them into a broader and more comprehensive global framework. The Global Justice Project is now available to explore on a dedicated website, that includes an interactive tool to explore the distributional pathways and climate scenarios behind the report.

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.

Les 10% des personnes les plus riches de la planète sont responsables des deux tiers du réchauffement climatique depuis 1990, selon une étude quantifiant pour la première fois l'impact de la concentration des richesses privées sur les événements climatiques extrêmes.