Jean Jouzel

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.

Scenarios serve as a critical tool in climate change analysis, enabling the exploration of future evolution of the climate system, climate impacts, and the human system (including mitigation and adaptation actions). This paper describes the scenario framework for ScenarioMIP as part of CMIP7. The design process has involved various rounds of interaction with the research community and user groups at large. The proposal covers a set of scenarios exploring high levels of climate change (to explore high-end climate risks), medium levels of climate change (anchored to current policy), and low levels of climate change (aligned with current international agreements). These scenarios follow very different trajectories in terms of emissions, with some likely to experience peaks and subsequent declines in greenhouse gas concentrations in this century. An important innovation is that most scenarios are intended to be run, if possible, in emission-driven mode, providing a better representation of the Earth system uncert

Dario Amodei questions if human systems are ready to handle the ‘almost unimaginable power’ that is ‘potentially imminent’

The decline in the health of nature around the world poses a threat to the UK's security and prosperity, an intelligence committee has concluded in a long-awaited report. The document warns of "cascading risks" from the degradation of some of the planet's most important ecosystems, including conflict, migration and increased competition for resources.

Climate regime shifts (CRSs), characterized by abrupt and persistent transitions between alternative stable states in the climate system, pose serious threats to ecosystems and human well-being. Understanding the potential drivers of CRSs is crucial, particularly in a warming world where CRSs are becoming more frequent.

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

Le Future Risks Report explore les risques auxquels nous pourrions être confrontés à l'avenir. Ce rapport s’appuie sur les conclusions d’une enquête annuelle menée auprès de 3 600 experts issus de 57 pays et 23 000 personnes représentatives de la population dans 18 pays, les invitant à classer les 10 principaux risques du futur, en fonction de leur impact potentiel sur la société pour les cinq à dix prochaines années.

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

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.

Ten kinds of possible collapses examined.