Jean-Marc Jancovici

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.

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 ! »

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.

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.

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.

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.

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.

Climate change is driving rising global temperatures, ecological degradation, and widespread human suffering. Yet, as a collective, humanity has failed to implement sufficient changes to mitigate these threats. This paper introduces the concept of “global narcissism” as a speculative lens to analyze the psychological barriers to climate action. By examining different levels of narcissism and their manifestations in human responses to climate change, this framework highlights key obstacles to meaningful action. While humanity is diverse, and lived experiences vary greatly, this perspective offers a way to discuss patterns of response and resistance. A central challenge lies in humanity’s difficulty in recognizing its symbiotic relationship with the non-human world. Through the metaphor of “global narcissism” this paper explores how humanity’s response to ecological crisis mirrors narcissistic defense mechanisms and suggests a collapse is taking place. This framework provides insights into how psychological int

Paper in Nature Climate Change journal reveals major role wealthy emitters play in driving climate extremes. The world’s wealthiest 10% are responsible for two-thirds of global heating since 1990, driving droughts and heatwaves in the poorest parts of the world, according to a study.

Springtails illustrate in new research how global warning and antibiotic resistance creates synergistic effects: warming increases pesticide toxicity, triggering antibiotic resistance which spreads through horizontal gene transfer and predation.

2023 set a number of alarming new records. The global mean temperature also rose to nearly 1.5 degrees Celsius above the preindustrial level, another record.A team led by the Alfred Wegener Institute puts forward a possible explanation for the rise in global mean temperature: our planet has become less reflective because certain types of clouds have declined. The work is published in the journal Science.

Metals and metalloids are ubiquitous in soils, originating from bedrock and from human activities and infrastructure. These compounds can be toxic to humans and other organisms, and their soil distribution and concentrations at global scale are not well known. Hou et al. analyzed data from more than 1000 regional studies to identify areas of metal toxicity and explore drivers of these trends. They estimate that 14 to 17% of cropland exceeds agricultural thresholds for at least one toxic metal.

A superpower in the fight against global heating is hiding in plain sight. It turns out that the overwhelming majority of people in the world – between 80% and 89%, according to a growing number of peer-reviewed scientific studies – want their governments to take stronger climate action.

We investigate the probabilities of triggering climate tipping points under five Shared Socioeconomic Pathways (SSPs) and how they are altered by including the additional carbon emissions that could arise from tipping points within the Earth's carbon cycle. The crossing of a climate tipping point at a threshold level of global mean surface temperature (threshold temperature) would commit the affected subsystem of the Earth to abrupt and largely irreversible changes with negative impacts on human well-being. However, it remains unclear which tipping points would be triggered under the different SSPs due to uncertainties in the climate sensitivity to anthropogenic greenhouse gas emissions, the threshold temperatures and timescales of climate tipping points, and the response of tipping points within the Earth's carbon cycle to global warming. We include those uncertainties in our analysis to derive probabilities of triggering for 16 previously identified climate tipping points within the Earth system.

La Suisse et le Nord de l’Italie ont subi des précipitations exceptionnelles, qui ne se produisaient avant qu’une fois par siècle. Un courant du sud très humide est monté vers les Alpes où un front froid est arrivé mercredi (MétéoSuisse 14 avril). Une pluie torrentielle a suivi ce choc de masses d’air.

Global temperature for 2025 should decline little, if at all, from the record 2024 level. Absence of a large temperature decline after the huge El Nino-spurred temperature increase in 2023-24 will provide further confirmation that IPCC’s best estimates for climate sensitivity and aerosol climate forcing were both underestimates. Specifically, 2025 global temperature should remain near or above +1.5C relative to 1880-1920, and, if the tropics remain ENSO-neutral, there is good chance that 2025 may even exceed the 2024 record high global temperature.

Tipping elements within the Earth system are increasingly well understood. Scientists have identified more than 25 parts of the Earth’s climate system that are likely to have “tipping points” – thresholds where a small additional change in global warming will cause them to irreversibly shift into a new state. The “tipping” of these systems – which include the Atlantic Meridional Overturning Circulation (AMOC), the Amazon rainforest and the Greenland ice sheet – would have profound consequences for both the biosphere and people. More recent research suggests that triggering one tipping element could cause subsequent changes in other tipping elements, potentially leading to a “tipping cascade”. For example, a collapsed AMOC could lead to dieback of the Amazon rainforest and hasten the melt of the Greenland ice sheet.

Les températures de la Planète augmenteront pendant les prochaines décennies. Les catastrophes climatiques s’aggraveront au cours de cette période. A 2°C, il y aura beaucoup plus d’inondations et des vagues de chaleur plus fortes. Nous les subirons de plein fouet, probablement au cours des vingt prochaines années (James E.Hansen).

Eat-Lancet report recommended shift to more plant-based, climate-friendly diet but was extensively attacked online [...] The report recommended that if global red meat eating was cut by 50%, the “planetary health diet” would provide nutritious food to all while tackling the harms caused by animal agriculture, which accounts for over 14% of all greenhouse gas emissions worldwide. It suggested individuals – particularly in wealthy countries – should increase their consumption of nuts, pulses and other plant-based foods while cutting meat and sugar from their diets.