.Contribution to (a) effective radiative forcing (ERF) and (b) global surface temperature change from component emissions for1750–2019based on Coupled Model Intercomparison Project Phase 6 (CMIP6) models and (c) net aerosol ERF for 1750–2014 from different lines of evidence.
Evidence shows a continuing increase in the frequency and severity of global heatwaves1,2, raising concerns about the future impacts of climate change and the associated socioeconomic costs3,4. Here we develop a disaster footprint analytical framework by integrating climate, epidemiological and hybrid input–output and computable general equilibrium global trade models to estimate the midcentury socioeconomic impacts of heat stress. We consider health costs related to heat exposure, the value of heat-induced labour productivity loss and indirect losses due to economic disruptions cascading through supply chains. Here we show that the global annual incremental gross domestic product loss increases exponentially from 0.03 ± 0.01 (SSP 245)–0.05 ± 0.03 (SSP 585) percentage points during 2030–2040 to 0.05 ± 0.01–0.15 ± 0.04 percentage points during 2050–2060. By 2060, the expected global economic losses reach a total of 0.6–4.6% with losses attributed to health loss (37–45%), labour productivity loss (18–37%) and i
Anthropogenic emissions drive global-scale warming yet the temperature increase relative to pre-industrial levels is uncertain. Using 300 years of ocean mixed-layer temperature records preserved in sclerosponge carbonate skeletons, we demonstrate that industrial-era warming began in the mid-1860s, more than 80 years earlier than instrumental sea surface temperature records. The Sr/Ca palaeothermometer was calibrated against ‘modern’ (post-1963) highly correlated (R2 = 0.91) instrumental records of global sea surface temperatures, with the pre-industrial defined by nearly constant (<±0.1 °C) temperatures from 1700 to the early 1860s. Increasing ocean and land-air temperatures overlap until the late twentieth century, when the land began warming at nearly twice the rate of the surface oceans. Hotter land temperatures, together with the earlier onset of industrial-era warming, indicate that global warming was already 1.7 ± 0.1 °C above pre-industrial levels by 2020. Our result is 0.5 °C higher than IPCC estim
Une expérience de 4 mois pour repenser notre rapport au vivant grâce aux low-tech
Produite à partir de cellules en prolifération dans des bioréacteurs, la « viande de culture » est présentée comme une solution à la demande grandissante en protéines animales sans certains des inconvénients de l’élevage. Ce premier article décrit les qualités sanitaires, nutritionnelles et organoleptiques à partir des connaissances disponibles. Un point d’attention concerne la composition et le coût du milieu de culture, notamment concernant les alternatives au sérum de veau fœtal. L’innocuité de ce nouvel aliment fait débat entre les scientifiques, avec, d’un côté ceux qui affirment que la consommation de la « viande de culture » sera plus sûre que celle de la viande conventionnelle, et ceux qui, au contraire, sont plus prudents, considérant que les risques sanitaires ne sont pas entièrement connus.
Les forêts françaises couvrent 31% du territoire métropolitain. Elles contribuent de multiples façons au bienêtre humain (production de bois, purification de l’air et de l’eau, maintien des sols, habitat pour la biodiversité, alimentation, santé, activités récréatives, etc.) et participent aux Objectifs de Développement Durable fixés par l’ONU. En particulier, la France s’étant engagée à atteindre la neutralité carbone dès 2050, le rôle de puits et de stockage de carbone des forêts est considéré comme un élément majeur de sa Stratégie Nationale Bas Carbone (SNBC). Depuis quelques années, les forêts françaises, dont la surface n’avait cessé de croître depuis plus d’un siècle, connaissent, de façon inquiétante, une diminution de productivité, des dépérissements massifs et un risque incendie accru. Le changement climatique en cours met ainsi en péril les ressources forestières et leur contribution attendue pour préserver la biodiversité, favoriser le développement rural et la bioéconomie, renforcer la production
Permafrost and glaciers in the high Arctic form an impermeable ‘cryospheric cap’ that traps a large reservoir of subsurface methane, preventing it from reaching the atmosphere. Cryospheric vulnerability to climate warming is making releases of this methane possible. On Svalbard, where air temperatures are rising more than two times faster than the average for the Arctic, glaciers are retreating and leaving behind exposed forefields that enable rapid methane escape. Here we document how methane-rich groundwater springs have formed in recently revealed forefields of 78 land-terminating glaciers across central Svalbard, bringing deep-seated methane gas to the surface. Waters collected from these springs during February–May of 2021 and 2022 are supersaturated with methane up to 600,000 times greater than atmospheric equilibration. Spatial sampling reveals a geological dependency on the extent of methane supersaturation, with isotopic evidence of a thermogenic source. We estimate annual methane emissions from prog
Terrestrial ecosystems have taken up about 32% of the total anthropogenic CO2 emissions in the past six decades1. Large uncertainties in terrestrial carbon–climate feedbacks, however, make it difficult to predict how the land carbon sink will respond to future climate change2. Interannual variations in the atmospheric CO2 growth rate (CGR) are dominated by land–atmosphere carbon fluxes in the tropics, providing an opportunity to explore land carbon–climate interactions3–6. It is thought that variations in CGR are largely controlled by temperature7–10 but there is also evidence for a tight coupling between water availability and CGR11. Here, we use a record of global atmospheric CO2, terrestrial water storage and precipitation data to investigate changes in the interannual relationship between tropical land climate conditions and CGR under a changing climate. We find that the interannual relationship between tropical water availability and CGR became increasingly negative during 1989–2018 compared to 1960–1989
Flash drought, characterized by unusually rapid drying, can have substantial impact on many socioeconomic sectors, particularly agriculture. However, potential changes to flash drought risk in a warming climate remain unknown. In this study, projected changes in flash drought frequency and cropland risk from flash drought are quantified using global climate model simulations. We find that flash drought occurrence is expected to increase globally among all scenarios, with the sharpest increases seen in scenarios with higher radiative forcing and greater fossil fuel usage. Flash drought risk over cropland is expected to increase globally, with the largest increases projected across North America (change in annual risk from 32% in 2015 to 49% in 2100) and Europe (32% to 53%) in the most extreme emissions scenario. Following low-end and medium scenarios compared to high-end scenarios indicates a notable reduction in annual flash drought risk over cropland. Flash droughts are projected to become more frequent unde
Climate change and human activities increasingly threaten lakes that store 87% of Earth’s liquid surface fresh water. Yet, recent trends and drivers of lake volume change remain largely unknown globally. Here, we analyze the 1972 largest global lakes using three decades of satellite observations, climate data, and hydrologic models, finding statistically significant storage declines for 53% of these water bodies over the period 1992–2020. The net volume loss in natural lakes is largely attributable to climate warming, increasing evaporative demand, and human water consumption, whereas sedimentation dominates storage losses in reservoirs. We estimate that roughly one-quarter of the world’s population resides in a basin of a drying lake, underscoring the necessity of incorporating climate change and sedimentation impacts into sustainable water resources management.
Global CO2 emissions for 2022 increased by 1.5% relative to 2021 (+7.9% and +2.0% relative to 2020 and 2019, respectively), reaching 36.1 GtCO2. These 2022 emissions consumed 13%–36% of the remaining carbon budget to limit warming to 1.5 °C, suggesting permissible emissions could be depleted within 2–7 years (67% likelihood).
Gestational exposure to ambient fine particles (PM2.5) increases the risk of stillbirth, but the related disease burden is unknown, particularly in low- and middle-income countries (LMICs). We combine state-of-the-art estimates on stillbirths, and multiple exposure–response functions obtained from previous meta-analyses or derived by a self-matched case-control study in 54 LMICs. 13,870 stillbirths and 32,449 livebirths are extracted from 113 geocoded surveys from the Demographic and Health Surveys. Each stillbirth is compared to livebirth(s) of the same mother using a conditional logit regression. We find that 10-µg/m3 increase of PM2.5 is associated with an 11.0% (95% confidence interval [CI] 6.4, 15.7) increase in the risk of stillbirth, and the association is significantly enhanced by maternal age. Based on age-specific nonlinear PM2.5–stillbirth curves, we evaluate the PM2.5-related stillbirths in 137 countries. In 2015, of 2.09 (95% CI: 1.98, 2.20) million stillbirths, 0.83 (0.54, 1.08) million or 39.7%
Météo, climat et GIEC Quel que soit l’endroit où nous habitons, nous vivons tous avec la météo : comment les conditions de notre atmosphère évoluent au fil des minutes, des heures, des jours et des semaines. Nous vivons également tous avec le climat, c’est-à-dire, en un lieu donné, l’ensemble des caractéristiques météorologiques moyennes sur plusieurs décennies. On parle de changement climatique lorsque ces conditions moyennes commencent à se modifier, du fait de causes naturelles ou du fait des activités humaines. La hausse des températures, les variations des précipitations, l’intensification de phénomènes météorologiques extrêmes sont autant d’exemples de changements climatiques, parmi bien d’autres caractéristiques
Understanding the recent history of Thwaites Glacier, and the processes controlling its ongoing retreat, is key to projecting Antarctic contributions to future sea-level rise. Of particular concern is how the glacier grounding zone might evolve over coming decades where it is stabilized by sea-floor bathymetric highs. Here we use geophysical data from an autonomous underwater vehicle deployed at the Thwaites Glacier ice front, to document the ocean-floor imprint of past retreat from a sea-bed promontory. We show patterns of back-stepping sedimentary ridges formed daily by a mechanism of tidal lifting and settling at the grounding line at a time when Thwaites Glacier was more advanced than it is today. Over a duration of 5.5 months, Thwaites grounding zone retreated at a rate of >2.1 km per year—twice the rate observed by satellite at the fastest retreating part of the grounding zone between 2011 and 2019. Our results suggest that sustained pulses of rapid retreat have occurred at Thwaites Glacier in the past
Climate change affects the Arctic and sub-Arctic regions by exposing previously frozen permafrost to thaw, unlocking soil nutrients, changing hydrological processes, and boosting plant growth. As a result, sub-Arctic tundra is subject to a shrub expansion, called “shrubification”, at the expense of sedge species. Depending on the intrinsic foliar properties of these plant species, changes in foliar mineral element fluxes with shrubification in the context of permafrost degradation may influence topsoil mineral element composition. Despite the potential implications of changes in topsoil mineral element concentrations for the fate of organic carbon, this remains poorly quantified. Here, we investigate vegetation foliar and topsoil mineral element composition (Si, K, Ca, P, Mn, Zn, Cu, Mo, V) across a natural gradient of permafrost degradation at a typical sub-Arctic tundra at Eight Mile Lake (Alaska, USA). Results show that foliar mineral element concentrations are higher (up to 9 times; Si, K, Mo for all spec
The fate, effects, and treatment of per- and polyfluoroalkyl substances (PFAS), an anthropogenic class of chemicals used in industrial and commercial production, are topics of great interest in recent research and news cycles. This interest stems from the ubiquity of PFAS in the global environment as well as their significant toxicological effects in humans and wildlife. Research on toxicity, sequestration, removal, and degradation of PFAS has grown rapidly, leading to a flood of valuable knowledge that can get swamped out in the perpetual rise in the number of publications. Selected papers from the Journal of Hazardous Materials between January 2018 and May 2022 on the toxicity, sequestration, and degradation of PFAS are reviewed in this article and made available as open-access publications for one year, in order to facilitate the distribution of critical knowledge surrounding PFAS. This review discusses routes of toxicity as observed in mammalian and cellular models, and the observed human health effects i
Ces fiches "radionucléides" (voir la liste ci-dessous) présentent sous forme synthétique le comportement et l'action des principaux radionucléides dans l'environnement (fiches environnement) et les conséquences connues sur l'homme (fiches santé). Rédigées par l’IRSN, elles sont volontairement simplifiées afin de mettre à la disposition de tous un support de connaissances facilement accessibles et compréhensibles ; elles ne traduisent donc pas toujours les nuances qui apparaissent dans la bibliographie. Elles permettent, en quelques pages, de connaître les caractéristiques essentielles qui gouvernent le comportement des radionucléides étudiés.
Human activity is putting the Earth on a trajectory towards environmental collapse. The SDGs were adopted in2015 to reconcile human activity with planetary boundaries. So far, the SDGs have not lived up to their promise in European Union member states. Most EU countries have seen socioeconomic development alongside environmental degradation. Progress towards environmental sustainability only occurs in countries with slow or negative socioeconomic trends.
L'empreinte environnementale du secteur numérique fait toujours l'objet de nombreux débats en France et en Europe. Du fait du manque de connaissances en sciences environnementales appliquées au secteur numérique, de nombreuses choses sont publiées et répétées sans être confrontées aux recherches récentes et vérifiées.
Solène Ducretot, co-fondatrice du collectif Les Engraineuses, explique l’importance d’imbriquer les luttes et de prendre conscience de l’interdépendance des problèmes de notre société.
The Working Group I contribution to the Sixth Assessment Report addresses the most up-to-date physical understanding of the climate system and climate change, bringing together the latest advances in climate science, and combining multiple lines of evidence from paleoclimate, observations, process understanding, and global and regional climate simulations.
An extreme technologically adapted future has not been defined in the literature. Such a future could be argued to be morally justifiable.However, a highly technologically mediated relationship with the biosphere introduces unique risks. These are likely to endanger humanity and future Earth-originating life-forms as well as creating moral hazard. An extreme technologically adapted future is therefore undesirable compared to restabilising the biosphere.
This Summary for Policymakers (SPM) presents key findings of the Working Group I (WGI) contribution to the IPCC’s Sixth Assessment Report (AR6)1 on the physical science basis of climate change. The report builds upon the 2013 Working Group I contribution to the IPCC’s Fifth Assessment Report (AR5) and the 2018–2019 IPCC Special Reports2 of the AR6 cycle and incorporates subsequent new evidence from climate science3.
The Working Group I contribution to the Sixth Assessment Report addresses the most up-to-date physical understanding of the climate system and climate change, bringing together the latest advances in climate science, and combining multiple lines of evidence from paleoclimate, observations, process understanding, and global and regional climate simulations.
The Summary for Policymakers (SPM) is the approved version from the 14th session of Working Group I and 54th Session of the Intergovernmental Panel on Climate Change and remains subject to final copy-editing and layout.
Meeting human needs at sustainable levels of energy use is fundamental for avoiding catastrophic climate change and securing the well-being of all people. In the current political-economic regime, no country does so. Here, we assess which socio-economic conditions might enable societies to satisfy human needs at low energy use, to reconcile human well-being with climate mitigation.
Editor’sNote: This essay by esteemed scientist James Hansen is a hybrid ofthe books’ foreword and an independent treatise on the accelerated warming of the planet
SI vous vous êtes déjà demandé quel était le lien entre la montée du niveau des océans et le changement climatique, nous espérons que cette planche vous aidera à y voir plus clair. Nous avons bénéficié de l'aide d'Anny Cazenave, chercheuse CNES au LEGOS (Laboratoire d'études en géophysique et océanographie spatiales), membre de l’Académie des sciences et l’un des principaux auteurs du chapitre « Élévation du niveau de la mer » du 5e rapport du Groupe d'experts intergouvernemental sur l'évolution du climat (GIEC).
Human activities are threatening to push the Earth system beyond its planetary boundaries, risking catastrophic and irreversible global environmental change. Action is urgently needed, yet well-intentioned policies designed to reduce pressure on a single boundary can lead, through economic linkages, to aggravation of other pressures. In particular, the potential policy spillovers from an increase in the global carbon price onto other critical Earth system processes has received little attention to date. To this end, we explore the global environmental effects of pricing carbon, beyond its effect on carbon emissions. We find that the case for carbon pricing globally becomes even stronger in a multi-boundary world, since it can ameliorate many other planetary pressures. It does however exacerbate certain planetary pressures, largely by stimulating additional biofuel production. When carbon pricing is allied with a biofuel policy, however, it can alleviate all planetary pressures. In the light of nine Earth Syst
Figurant comme une des obligations de l’Accord de Paris ratifié en 2016, l’éducation au changement climatique est un outil précieux pour agir à grande échelle sur les comportements et les choix des sociétés.
– Sites – Documents – Des Appels – Livres – B&L – Vidéos – 