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Cet été a été marqué par d'importantes vagues de chaleur entraînant une forte surmortalité. Entre le 18 juin et le 3 juillet 2026, 2 035 décès supplémentaires ont été recensés en Belgique, soit 50% de plus que la normale à cette période. Sur l'ensemble de l'été 2026, on arrive à 2 935 décès liés à la chaleur en Belgique. Quelle part de responsabilité le réchauffement climatique a-t-il dans cette surmortalité ? Comment notre corps réagit-il aux températures élevées ? Sommes-nous toutes et tous égaux·ales face aux canicules ? Comment s’adapter à ce monde de plus en plus chaud ? Cette Lettre synthétise les principaux liens entre climat et santé. L’épidémiologiste français Kévin Jean a répondu à nos questions de manière à la fois précise et pédagogique; nous l’en remercions chaleureusement, ainsi que pour sa disponibilité.

The term ‘Anthropocene’ was coined in recognition that human activities have ended the relatively stable environment of the Holocene epoch. However, its widespread adoption across the humanities, arts and sciences has led to diverse and sometimes incompatible definitions. In this Perspective, we argue for a stabilized definition of the Anthropocene epoch to help address contemporary environmental challenges, and explore various applications of the Anthropocene across disciplines. The Anthropocene epoch, with a proposed start point in 1952, underscores that human-driven global-scale environmental disruption differs from earlier human impacts of the Holocene, which did not cause such profound destabilization. This clear distinction enables quantitative and qualitative comparisons between the Holocene and Anthropocene epochs, as already utilized, for instance, within the planetary boundaries framework. As the Anthropocene Earth system transformation is systemic, political responses also need be systemic, rather

La sensibilité climatique caractérise l'évolution de la température de l'atmosphère terrestre en réponse à un forçage radiatif donné. C'est un paramètre de la modélisation du réchauffement climatique. La sensibilité du climat au CO2 est souvent exprimée comme la variation de température en degrés Celsius associée à un doublement de la concentration de dioxyde de carbone dans l'atmosphère terrestre.

En France, la chute du puits de carbone forestier est régulièrement présentée par les pouvoirs publics comme une fatalité. Cette note démontre que cet argument n’est qu’en partie fondé : il existe des leviers politiques pour amortir cette chute et respecter les engagements internationaux de la France. Le principal de ces leviers est de limiter les prélèvements de bois plutôt que de chercher à les augmenter comme le propose la Stratégie nationale bas carbone.

« Les rapports du GIEC » : on en entend souvent parler dans les médias, mais on ne sait pas toujours ce qui se cache derrière. Que renferment ces fameux rapports ? Qui les rédige ? Quel rôle jouent les réprésentant·e·s gouvernementaux·ales ? Où en est le GIEC aujourd’hui ? Quels sont les prochains sujets qui seront abordés ? À quoi servent les groupes de travail ? Dans cette Lettre, nous tentons d’apporter une réponse à ces différentes questions. Nous revenons d’abord sur la logique et le fonctionnement des rapports du GIEC, avant de présenter les rapports en cours de préparation ainsi que leur calendrier de publication. Ces explications sont enrichies par des témoignages et éclairages d’expert·e·s impliqué·e·s dans la rédaction des rapports. Bonne lecture !

We infer that 2026 is likely to be the warmest year in the period of instrumental data, based on a physics-based approach with identifiable assumptions. This approach may help us learn something in 2026 about the mechanisms of climate change. The figures in this post and our other current papers will be continually updated on our website,2 when they remain relevant. We are also now on Substack3.

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

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.

Retranscription de la conférence d'Olivier Hamant organisée par le CAL Namur […] Olivier Hamant nous invite à questionner notre quête permanente de contrôle et de performance. A l'heure des bouleversements écologiques, il propose un regard original : et si nous nous inspirons du vivant ? Lent, imparfait et vulnérable, il nous montre qu'une autre manière d'organiser nos sociétés est possible, plus robuste et plus humaine.

Comprendre pourquoi l’hydrogène est en difficulté en France, en 2 minutes

Alors que les scientifiques s’inquiètent depuis de nombreuses années de l’imminence d’un point de bascule de l’Amazonie, à partir duquel la forêt, à force de déforestation et dégradation, s’assècherait au point de devenir une savane, notre analyse démontre que les négociants Bunge et Cargill sont exposés à un risque de déforestation liée au soja, sur une surface de 102 800 hectares au Brésil, depuis janvier 2024.

We propose a new paradigm, as toxicology currently lacks the proper perspective. From the 1950s to the 1970s, at least one-third of all toxicological testing in the United States, including for chemicals and drugs, was misleading scientists, and this worldwide issue persists today. Moreover, petroleum-based waste and heavy metals have been discovered in pesticide and plasticizer formulations. These contaminations have now reached all forms of life. Widespread exposure to chemical mixtures promotes health and environmental risks. We discovered that pesticides have never undergone long-term testing on mammals in their full commercial formulations by regulatory authorities or the pesticide industry; instead, only their declared active ingredients have been assessed, contrary to environmental law recommendations. The ingredients of these formulations are not fully disclosed, yet the formulations are in general at least 1000 times more toxic at low environmentally relevant doses than the active ingredients alone u

We are hurtling toward climate chaos. The planet's vital signs are flashing red. The consequences of human-driven alterations of the climate are no longer future threats but are here now. This unfolding emergency stems from failed foresight, political inaction, unsustainable economic systems, and misinformation. Almost every corner of the biosphere is reeling from intensifying heat, storms, floods, droughts, or fires. The window to prevent the worst outcomes is rapidly closing. In early 2025, the World Meteorological Organization reported that 2024 was the hottest year on record (WMO 2025a). This was likely hotter than the peak of the last interglacial, roughly 125,000 years ago (Gulev et al. 2021, Kaufman and McKay 2022). Rising levels of greenhouse gases remain the driving force behind this escalation. These recent developments emphasize the extreme insufficiency of global efforts to reduce greenhouse gas emissions and mark the beginning of a grim new chapter for life on Earth.

Analysis and forecast to 2030

Première école supérieure dédiée à l’agriculture biologique et à l’agroécologie bio.

Purpose Animal emissions account for nearly 60% of total greenhouse gas emissions from the livestock sector. To estimate these emissions, the Food and Agriculture Organization of the United Nations (FAO) developed a dedicated module within the Global Livestock Environmental Assessment Model (GLEAM). Although previous studies have explored selected inputs for specific animals and emission types, a comprehensive analysis of all 92 inputs (parameters and emission factors) had not been conducted. This study aimed to identify the most influential inputs affecting ruminant emissions in GLEAM.

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.

Cette nouvelle étude du Forum Vies Mobiles analyse le coût global du système voiture en France, sur la base des chiffres les plus récents portant sur l’année 2023. Ce travail, réalisé avec le Laboratoire Economie Aménagement Transport (LAET) de Lyon, prend en compte non seulement les dépenses directes des usagers (ménages, entreprises, administrations), mais aussi les coûts supportés par la puissance publique et la société, incluant les externalités négatives telles que la pollution de l’air, le CO2 ou les accidents. L’objectif est d’identifier les différents postes de dépense liés à la voiture et de les quantifier, afin de proposer un panorama complet et inédit des coûts associés à l’automobile.

Why is the Trump Administration trying to kill a small space science institute in New York City? Explanation begins with Galileo’s method of scientific inquiry and ends with the role of special interest money in the United States government. Galileo improved the telescope, allowing clearer observations of the planets and the Sun. Galileo differed from his peers, as he was unafraid to challenge authority. He claimed that the world should be understood based on observations, and he spoke directly to the public. He obtained philanthropic support for his observations and openly described the conclusion that Earth was not the center of the solar system – Earth revolved around the Sun.

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