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Global Change
05 juin 2024
Annually updated, IPCC AR6 consistent indicators of human-induced global warming, greenhouse gas emissions, and the remaining global carbon budget.
Abstract. Intergovernmental Panel on Climate Change (IPCC) assessments are the trusted source of scientific evidence for climate negotiations taking place under the United Nations Framework Convention on Climate Change (UNFCCC). Evidence-based decision-making needs to be informed by up-to-date and timely information on key indicators of the state of the climate system and of the human influence on the global climate system. However, successive IPCC reports are published at intervals of 5–10 years, creating potential for an information gap between report cycles. We follow methods as close as possible to those used in the IPCC Sixth Assessment Report (AR6) Working Group One (WGI) report. We compile monitoring datasets to produce estimates for key climate indicators related to forcing of the climate system: emissions of greenhouse gases and short-lived climate forcers, greenhouse gas concentrations, radiative forcing, the Earth's energy imbalance, surface temperature changes, warming attributed to human activit
22 avril 2024
Over the past 50 years, humans have extracted the Earth’s groundwater stocks at a steep rate, largely to fuel global agro-economic development. Given society’s growing reliance on groundwater, we explore ‘peak water limits’ to investigate whether, when and where humanity might reach peak groundwater extraction. Using an integrated global model of the coupled human–Earth system, we simulate groundwater withdrawals across 235 water basins under 900 future scenarios of global change over the twenty-first century. Here we find that global non-renewable groundwater withdrawals exhibit a distinct peak-and-decline signature, comparable to historical observations of other depletable resources (for example, minerals), in nearly all (98%) scenarios, peaking on average at 625 km3 yr−1 around mid-century, followed by a decline through 2100. The peak and decline occur in about one-third (82) of basins, including 21 that may have already peaked, exposing about half (44%) of the global population to groundwater stress. Most
17 avril 2024
Global projections of macroeconomic climate-change damages typically consider impacts from average annual and national temperatures over long time horizons1–6. Here we use recent empirical findings from more than 1,600 regions worldwide over the past 40 years to project sub-national damages from temperature and precipitation, including daily variability and extremes7,8. Using an empirical approach that provides a robust lower bound on the persistence of impacts on economic growth, we find that the world economy is committed to an income reduction of 19% within the next 26 years independent of future emission choices (relative to a baseline without climate impacts, likely range of 11–29% accounting for physical climate and empirical uncertainty). These damages already outweigh the mitigation costs required to limit global warming to 2 °C by sixfold over this near-term time frame and thereafter diverge strongly dependent on emission choices. Committed damages arise predominantly through changes in average tempe
13 mars 2024
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
09 février 2024
Mitigating climate change necessitates global cooperation, yet global data on individuals’ willingness to act remain scarce. In this study, we conducted a representative survey across 125 countries, interviewing nearly 130,000 individuals. Our findings reveal widespread support for climate action. Notably, 69% of the global population expresses a willingness to contribute 1% of their personal income, 86% endorse pro-climate social norms and 89% demand intensified political action. Countries facing heightened vulnerability to climate change show a particularly high willingness to contribute. Despite these encouraging statistics, we document that the world is in a state of pluralistic ignorance, wherein individuals around the globe systematically underestimate the willingness of their fellow citizens to act. This perception gap, combined with individuals showing conditionally cooperative behaviour, poses challenges to further climate action. Therefore, raising awareness about the broad global support for climat
05 février 2024
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
28 août 2023
As we mark 100 days until the COP28 UN climate summit, the urgency of addressing the climate crisis has never been more palpable. Global failures to mitigate emissions and adapt to the impacts continue to wreak havoc on the planet, and we’re seeing this in a range of ways. Unprecedented extreme weather events have occurred with frightening regularity in 2023. In March, over 500 people lost their lives when Cyclone Freddy struck Malawi. Last month, flooding in the Philippines caused by Typhoons Doksuri and Khanun displaced more than 300,000 people, and the recent wildfires that ravaged Hawaii – in part exacerbated by climate change – continue to make for distressing headlines. This list is likely to become even longer by the end of the year, when COP28 gets underway in the United Arab Emirates (UAE).
09 juin 2023
Een internationaal team van wetenschappers werkt aan een systeem dat de achtjaarlijkse rapporten van het VN-klimaatpanel aanvult met een actuele stand van zaken per jaar. Klimaatexpert Piers Forster van de Universiteit van Leeds legt uit waarom dat zo belangrijk is, en wat de laatste bevindingen zijn.
08 juin 2023
Abstract. Intergovernmental Panel on Climate Change (IPCC) assessments are the trusted source of scientific evidence for climate negotiations taking place under the United Nations Framework Convention on Climate Change (UNFCCC), including the first global stocktake under the Paris Agreement that will conclude at COP28 in December 2023. Evidence-based decision-making needs to be informed by up-to-date and timely information on key indicators of the state of the climate system and of the human influence on the global climate system. However, successive IPCC reports are published at intervals of 5–10 years, creating potential for an information gap between report cycles. We follow methods as close as possible to those used in the IPCC Sixth Assessment Report (AR6) Working Group One (WGI) report. We compile monitoring datasets to produce estimates for key climate indicators related to forcing of the climate system: emissions of greenhouse gases and short-lived climate forcers, greenhouse gas concentrations, radia
11 janvier 2023
Cette première partie de conférence traite de l'histoire de nos sociétés de consommation à la mode occidentale grâce aux énergies modernes esssentiellement f...
19 octobre 2022
Concerns about climate change shrank across the world last year, with fewer than half of those questioned in a new survey believing it posed a “very serious threat” to their countries over the next 20 years.
17 août 2022
L’introduction du concept d’Anthropocène – sous ce terme et avec les arguments scientifiques de la recherche contemporaine, en glaciologie et paléoclimatologie notamment – se situe significativement dans le cadre du Programme International Géosphère-Biosphère (IGBP), c’est-à-dire au cœur de la coopération scientifique internationale mobilisée autour du fameux « Global Change » : expression d’origine américaine (proche des « recherches biosphériques » et atmosphériques de la Nasa) qui désigne la problématique des transformations environnementales, naturelles et anthropogéniques (d’origine humaine), à l’échelle du Globe, notre « globe terraqué » (composé de terre et d’eau), comme disait les naturalistes et natural philosophers de l’Europe chrétienne classique, ou si l’on préfère préindustrielle et encore néolithique. ...
28 juillet 2022
Increasing risks posed by climate change are causing rare extreme events that can kill more than 10 million people or lead to damages of $10 trillion-plus, posing threats of total societal collapse, a UN report finds.
23 mai 2022
Food supply expert paints grim global picture hunger 05.23.2022 By Arvin Donley NEW YORK, NEW YORK, US — Global wheat inventories currently stand at about 10 weeks of global consumption, a food supply expert said during a special meeting of the United Nations Security Council on May 19. Sara Menker, chief executive officer of Gro Intelligence, an organization that gathers and analyzes global food and agricultural data, said she disputes official government agency estimates that put global wheat inventories at 33% of annual consumption, countering inventories are closer to 20%. “It is important to note that the lowest grain inventory levels the world has ever seen are now occurring while access to fertilizers is highly constrained, and drought in wheat growing regions around the world is the most extreme it’s been in over 20 years,” Menker said. “Similar inventory concerns also apply to corn and other grains. Government estimates are not adding up.” Menker told the security council that while much of the blame
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22 mai 2022
Long before the current political divide over climate change, and even before the U.S. Civil War (1861-1865), an American scientist named Eunice Foote documented the underlying cause of today’s climate change crisis. The year was 1856. Foote’s brief scientific paper was the first to describe the extraordinary power of carbon dioxide gas to absorb heat – the driving force of global warming. Carbon dioxide is an odorless, tasteless, transparent gas that forms when people burn fuels, including coal, oil, gasoline and wood.
21 mai 2022
The Bank of England governor warned last week of ‘apocalyptic’ food price rises. Yet war in Ukraine, climate change and inflation are already taking their toll all over the world. Apocalypse is an alarming idea, commonly taken to denote catastrophic destruction foreshadowing the end of the world. But in the original Greek, apokálypsis means a revelation or an uncovering. One vernacular definition is “to take the lid off something”.
12 mai 2022
When people talk about ways to slow climate change, they often mention trees, and for good reason. Forests take up a large amount of the planet-warming carbon dioxide that people put into the atmosphere when they burn fossil fuels. But will trees keep up that pace as global temperatures rise? With companies increasingly investing in forests as offsets, saying it cancels out their continuing greenhouse gas emissions, that’s a multibillion-dollar question.
06 mai 2022
Des chercheurs ont récemment mis en lumière un mécanisme par lequel les changements de banquise en Arctique parviennent à influencer le climat de régions situées bien au-delà du cercle polaire. Les résultats ont été publiés dans la revue Nature Communications le 19 avril dernier.
04 mai 2022
Previous studies show that city metrics having to do with growth, productivity and overall energy consumption scale superlinearly, attributing this to the social nature of cities. Superlinear scaling results in crises called ‘singularities’, where population and energy demand tend to infinity in a finite amount of time, which must be avoided by ever more frequent ‘resets’ or innovations that postpone the system's collapse. Here, we place the emergence of cities and planetary civilizations in the context of major evolutionary transitions. With this perspective, we hypothesize that once a planetary civilization transitions into a state that can be described as one virtually connected global city, it will face an ‘asymptotic burnout’, an ultimate crisis where the singularity-interval time scale becomes smaller than the time scale of innovation. If a civilization develops the capability to understand its own trajectory, it will have a window of time to affect a fundamental change to prioritize long-term homeosta
02 mai 2022
A new study describes a period of rapid global climate change in an ice-capped world much like the present—but 304 million years ago. Within about 300,000 years, atmospheric carbon dioxide levels doubled, oceans became anoxic, and biodiversity dropped on land and at sea.
20 avril 2022
The world may be facing a devastating “hidden” collapse in insect species due to the twin threats of climate change and habitat loss.
15 avril 2022
Le changement climatique a augmenté les précipitations de 5% lors de la saison record des ouragans de l’Atlantique en 2020. Au cours des 14 tempêtes qui ont atteint le statut d’ouragan, les précipitations ont été 8 % plus importantes, selon une étude publiée dans Nature Communications.
05 avril 2022
Rapid decarbonization of energy is non-negotiable if we are to avert catastrophic global heating, says the latest UN climate report.
04 avril 2022
The Working Group III report provides an updated global assessment of climate change mitigation progress and pledges, and examines the sources of global emissions. It explains developments in emission reduction and mitigation efforts, assessing the impact of national climate pledges in relation to long-term emissions goals.
27 mars 2022
Une plateforme de glace de la taille de la ville de Rome s’est effondrée en Antarctique de l’Est le 15 mars 2022, dans une zone longtemps considérée comme relativement épargnée par le changement climatique. L’effondrement s’est produit au début d’une « vague de chaleur » exceptionnelle dans la région de l’Antarctique de l’Est, qui a vu par endroits des température dépasser de 40°C les normales de saison.
17 mars 2022
Environmentalists once saw abstraction as the biggest obstacle to climate action. How, they wondered, could one focus the public on the distant future? Today, we confront the opposite problem, with the very immediacy of the crisis generating a strange paralysis. When the Intergovernmental Panel on Climate Change warned that global heating made extreme flooding more common, its new report at the end of February spurred relatively little discussion – in part because of the water covering swathes of Queensland and New South Wales. As tinnies plucked desperate residents from the deluge, who could give due weight to the warning from Prof Brendan Mackey, one of the IPPC authors, that the science clearly projected “an increase of heavy rainfall events?”
16 mars 2022
Capitalism isn’t what it used to be. Since 2008, critics of the world’s dominant economic system have been lamenting its imperviousness to change. And for good reason. In earlier epochs, financial crises and pandemics wrought economic transformation. In our own, they seem to have yielded more of the same. Before the 2008 crash, global capitalism was characterized by organized labor’s weakness, rising inequality within nations, and a growth model that offset mediocre wage gains with asset-price appreciation. All of these have remained features of the world’s economic order.
01 mars 2022
The inventor of the Brics acronym says sanctions against Russia have exposed nations’ dependence on the western economic system
28 février 2022
The Working Group II contribution to the IPCC Sixth Assessment Report assesses the impacts of climate change, looking at ecosystems, biodiversity, and human communities at global and regional levels. It also reviews vulnerabilities and the capacities and limits of the natural world and human societies to adapt to climate change.
11 février 2022
Momentum to phase out unabated coal use is growing globally. This transition is critical to meeting the Paris climate goals but can potentially lead to large amounts of stranded assets, especially in regions with newer and growing coal fleets. Here we combine plant-level data with a global integrated assessment model to quantify changes in global stranded asset risks from coal-fired power plants across regions and over time. With new plant proposals, cancellations, and retirements over the past five years, global net committed emissions in 2030 from existing and planned coal plants declined by 3.3 GtCO2 (25%). While these emissions are now roughly in line with initial Nationally Determined Contributions (NDCs) to the Paris Agreement, they remain far off track from longer-term climate goals. Progress made in 2021 towards no new coal can potentially avoid a 24% (503 GW) increase in capacity and a 55% ($520 billion) increase in stranded assets under 1.5 °C. Stranded asset risks fall disproportionately on emergin
08 février 2022
Tree diversity is fundamental for forest ecosystem stability and services. However, because of limited available data, estimates of tree diversity at large geographic domains still rely heavily on published lists of species descriptions that are geographically uneven in coverage. These limitations have precluded efforts to generate a global perspective. Here, based on a ground-sourced global database, we estimate the number of tree species at biome, continental, and global scales. We estimated a global tree richness (≈73,300) that is ≈14% higher than numbers known today, with most undiscovered species being rare, continentally endemic, and tropical or subtropical. These results highlight the vulnerability of global tree species diversity to anthropogenic changes.
12 janvier 2022
Berkeley Earth, a California-based non-profit research organization, has been preparing independent analyses of global mean temperature changes since 2013. The following is our report on global mean temperature during 2021.
03 décembre 2021
Climate change has important implications for the health and futures of children and young people, yet they have little power to limit its harm, making them vulnerable to climate anxiety. This is the first large-scale investigation of climate anxiety in children and young people globally and its relationship with perceived government response.
18 novembre 2021
Emerging ice-sheet modeling suggests once initiated, retreat of the Antarctic Ice Sheet (AIS) can continue for centuries. Unfortunately, the short observational record cannot resolve the tipping points, rate of change, and timescale of responses. Iceberg-rafted debris data from Iceberg Alley identify eight retreat phases after the Last Glacial Maximum that each destabilized the AIS within a decade, contributing to global sea-level rise for centuries to a millennium, which subsequently re-stabilized equally rapidly.
24 octobre 2021
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.
20 octobre 2021
Total a sciemment minimisé son rôle dans la menace du changement climatique, selon des scientifiques
- AfpChristophe Bonneuil, directeur de recherche au CNRS, Pierre-Louis Choquet, sociologue à Sciences po, et Benjamin Franta, chercheur en histoire à l'université américaine de Stanford, ont étudié les archives du groupe pétrolier, devenu TotalEnergies, ainsi que des revues internes et des interviews, selon cet article publié dans la revue Global Environmental Change.
04 octobre 2021
Les forêts européennes sont jusqu'à dix degrés plus froides en été et jusqu'à 12 degrés plus chaudes en hiver, ressort-il d'une étude à grande échelle de la KU Leuven, de l'UAntwerp et de l'UGent. C'est la première fois que l'effet isolant des forêts est cartographié de manière aussi détaillée. L'étude a été publiée lundi dans la revue scientifique Global Change Biology.
The most important climate talk at the highest political level—since the Paris climate conference in 2015—is set to take place in Glasgow, Scotland this year, from October 31 to November 12. This is the 26th Conference of Parties (COP26) of the United Nations Framework Convention on Climate Change (UNFCCC). This is not only the largest global climate summit, but also the largest global event as the sheer existence of the world will depend on the outcome of this year's conference.
19 août 2021
Texte de Jean-David Zeitoun, docteur en médecine, docteur en épidémiologie clinique et auteur de La grande extension : histoire de la santé humaine. En 2006, le British Medical Journal écrivait que « le changement climatique en lien avec le réchauffement global est le problème de santé publique le plus urgent dans le monde ».