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climate

mai 2024

Climate Obstruction Across Europe, coordinated by the Climate Social Science Network (CSSN) and published via Oxford University Press, reveals extensive networks impeding climate action within the region and surrounding states. In Italy and Germany, far-right networks spread misinformation by questioning climate science’s validity, while in Spain and the UK, blame-shifting and deflecting responsibility for climate action are common. European-based fossil fuel industries, like Shell, engage in greenwashing, by framing gas as a ‘bridging technology crucial for the energy transition’, delaying genuine progress.
Climate Obstruction Across Europe, coordinated by the Climate Social Science Network (CSSN), is the first book to document the development and nature of climate obstruction activities across Europe, which are efforts to deliberately slow or block climate action. Climate obstruction strategies range from outright denial to more subtle forces of delay and the spread of disinformation

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

mars 2024

.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.
Taking into account all known factors, the planet warmed 0.2 °C more last year than climate scientists expected. More and better data are urgently needed. Taking into account all known factors, the planet warmed 0.2 °C more last year than climate scientists expected. More and better data are urgently needed.
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

février 2024

We owe all children a planet Earth as wonderful as the one we have enjoyed!
Ce rapport analyse les obstacles et leviers à la lumière de projets inspirants en matière d'adaptation des villes à l'élévation du niveau de la mer dans le Pacifique.
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
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

novembre 2023

The State of the Cryosphere 2023 – Two Degrees is Too High report shows that all of the Earth’s frozen parts will experience irreversible damage at 2°C of global warming, with disastrous consequences for millions of people, societies, and nature. Confirming that just 2°C of global warming will trigger irreversible loss to Earth’s ice sheets, mountain glaciers and snow, sea ice, permafrost, and polar oceans, it updates the latest science and highlights the global impacts from cryosphere loss.

octobre 2023

Life on planet Earth is under siege. We are now in an uncharted territory. For several decades, scientists have consistently warned of a future marked by extreme climatic conditions because of escalating global temperatures caused by ongoing human activities that release harmful greenhouse gasses into the atmosphere. Unfortunately, time is up. We are seeing the manifestation of those predictions as an alarming and unprecedented succession of climate records are broken, causing profoundly distressing scenes of suffering to unfold. We are entering an unfamiliar domain regarding our climate crisis, a situation no one has ever witnessed firsthand in the history of humanity.
Ocean-driven melting of floating ice-shelves in the Amundsen Sea is currently the main process controlling Antarctica’s contribution to sea-level rise. Using a regional ocean model, we present a comprehensive suite of future projections of ice-shelf melting in the Amundsen Sea. We find that rapid ocean warming, at approximately triple the historical rate, is likely committed over the twenty-first century, with widespread increases in ice-shelf melting, including in regions crucial for ice-sheet stability. When internal climate variability is considered, there is no significant difference between mid-range emissions scenarios and the most ambitious targets of the Paris Agreement. These results suggest that mitigation of greenhouse gases now has limited power to prevent ocean warming that could lead to the collapse of the West Antarctic Ice Sheet. The authors use a regional ocean model to project ocean-driven ice-shelf melt in the Amundsen Sea. Already committed rapid ocean warming drives increased melt, regard

juillet 2023

Simultaneous harvest failures across major crop-producing regions are a threat to global food security. Concurrent weather extremes driven by a strongly meandering jet stream could trigger such events, but so far this has not been quantified. Specifically, the ability of state-of-the art crop and climate models to adequately reproduce such high impact events is a crucial component for estimating risks to global food security. Here we find an increased likelihood of concurrent low yields during summers featuring meandering jets in observations and models. While climate models accurately simulate atmospheric patterns, associated surface weather anomalies and negative effects on crop responses are mostly underestimated in bias-adjusted simulations. Given the identified model biases, future assessments of regional and concurrent crop losses from meandering jet states remain highly uncertain. Our results suggest that model-blind spots for such high-impact but deeply-uncertain hazards have to be anticipated and acc
This Research Plan was prepared in response to a requirement in the joint explanatory statement accompanying Division B of the Consolidated Appropriations Act, 2022, directing the Office of Science and Technology Policy (OSTP), with support from the National Oceanic and Atmospheric Administration (NOAA), to provide a research plan for “solar and other rapid climate interventions.”

juin 2023

Summary for Policymakers. A Report of the Intergovernmental Panel on Climate Change
Improved knowledge of glacial-to-interglacial global temperature change implies that fastfeedback equilibrium climate sensitivity (ECS) is 1.2 ± 0.3°C (2σ) per W/m2 . Consistent analysis of temperature over the full Cenozoic era – including “slow” feedbacks by ice sheets and trace gases – supports this ECS and implies that CO2 was about 300 ppm in the Pliocene and 400 ppm at transition to a nearly ice-free planet, thus exposing unrealistic lethargy of ice sheet models. Equilibrium global warming including slow feedbacks for today’s human-made greenhouse gas (GHG) climate forcing (4.1 W/m2) is 10°C, reduced to 8°C by today’s aerosols. Decline of aerosol emissions since 2010 should increase the 1970-2010 global warming rate of 0.18°C per decade to a post-2010 rate of at least 0.27°C per decade. Under the current geopolitical approach to GHG emissions, global warming will likely pierce the 1.5°C ceiling in the 2020s and 2°C before 2050. Impacts on people and nature will accelerate as global warming pumps up hydr

mai 2023

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
WMO's annual State of the Climate in Europe report explores changes in climate indicators, extreme events and climate policy.
Mitigation of Climate Change - Working Group III contribution to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change

avril 2023

Wind and solar reached a record 12% of global electricity in 2022, and power sector emissions may have peaked.

mars 2023

This paper catalogues current efforts to address climate change within multilateral economic and financial institutions and related organizations. It also proposes a minimum set of policy measures that need to be prioritized by such institutions to support climate change mitigation and adaptation. The proposals include expanding public climate finance via multilateral development banks, doing more to mobilize private investment, mainstreaming climate considerations across institutional operations, making climate disclosures mandatory, and addressing sovereign debt distress to unlock private climate finance.
La Niña is present.* Equatorial sea surface temperatures (SSTs) are below average across most of the Pacific Ocean. The tropical Pacific atmosphere is consistent with La Niña. La Niña is expected to continue into the winter, with equal chances of La Niña and ENSO-neutral during January-March 2023. In February-April 2023, there is a 71% chance of ENSO-neutral.*
The IPCC is currently in its Sixth Assessment cycle, during which the IPCC will produce the Assessment reports of its three Working Groups, three Special Reports, a refinement to the methodology report and the Synthesis Report. The Synthesis Report will be the last of the AR6 products, due for release in March 2023.
INTERLAKEN, Switzerland, March 20, 2023 -- There are multiple, feasible and effective options to reduce greenhouse gas emissions and adapt to human-caused climate change, and they are available now, said scientists in the latest Intergovernmental Panel on Climate Change (IPCC) report released today. ...
AR6 Synthesis Report
Net-zero targets imply that continuing residual emissions will be balanced by carbon dioxide removal. However, residual emissions are typically not well defined, conceptually or quantitatively. We analysed governments’ long-term strategies submitted to the UNFCCC to explore projections of residual emissions, including amounts and sectors. We found substantial levels of residual emissions at net-zero greenhouse gas emissions, on average 18% of current emissions for Annex I countries. The majority of strategies were imprecise about which sectors residual emissions would originate from, and few offered specific projections of how residual emissions could be balanced by carbon removal. Our findings indicate the need for a consistent definition of residual emissions, as well as processes that standardize and compare expectations about residual emissions across countries. This is necessary for two reasons: to avoid projections of excessive residuals and correspondent unsustainable or unfeasible carbon-removal level

janvier 2023

The climate crisis has begun to disrupt human societies by severely affecting the very foundations of human livelihood and social organisation. Climate impacts are not equally distributed across the world: on average, low- and middle-income countries suffer greater impacts than their richer counterparts. At the same time, the climate crisis is also marked by significant inequalities within countries. Recent research reveals a high concentration of global greenhouse gas emissions among a relatively small fraction of the population, living in emerging and rich countries. In addition, vulnerability to numerous climate impacts is strongly linked to income and wealth, not just between countries but also within them.
We are writing to urge you to push the United Arab Emirates to withdraw the appointment of Sultan Al Jaber, head of the Abu Dhabi National Oil Company, as President-designate of the United Nations Framework Convention on Climate Change Conference of Parties 28 (COP 28). The decision to name the chief executive of one of the world’s largest oil and gas companies as president of the next U.N. Climate Change Conference risks jeopardizing climate progress from successive U.N. Climate Conferences. To help ensure that COP 28 is a serious and productive climate summit, we believe the United States should urge the United Arab Emirates to name a different lead for COP 28 or, at a minimum, seek assurances that it will promote an ambitious COP 28 aligned with the 1.5 degrees Celsius limit and Intergovernmental Panel on Climate Change (IPCC) findings and take concrete steps to demonstrate domestic and regional leadership toward this end.

décembre 2022

Improved knowledge of glacial-to-interglacial global temperature change implies that fast- feedback equilibrium climate sensitivity is at least ~4°C for doubled CO2 (2×CO2), with likely range 3.5-5.5°C. Greenhouse gas (GHG) climate forcing is 4.1 W/m2 larger in 2021 than in 1750, equivalent to 2×CO2 forcing. Global warming in the pipeline is greater than prior estimates. Eventual global warming due to today’s GHG forcing alone – after slow feedbacks operate – is about 10°C. Human-made aerosols are a major climate forcing, mainly via their effect on clouds. We infer from paleoclimate data that aerosol cooling offset GHG warming for several millennia as civilization developed. A hinge-point in global warming occurred in 1970 as increased GHG warming outpaced aerosol cooling, leading to global warming of 0.18°C per decade. Aerosol cooling is larger than estimated in the current IPCC report, but it has declined since 2010 because of aerosol reductions in China and shipping. Without unprecedented global actions to
Mitigation of Climate Change - Working Group III contribution to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change

novembre 2022

Read Prime Minister Alexander De Croo's full speech at the climate conference in Sharm El Sheikh here. In his speech, the Prime Minister made the case for inclusivity and cooperation to tackle the climate crisis. Young, old, private, public sector, north, south, we must all go all-in to tackle today's challenges

octobre 2022

UN Climate Change News, 26 October 2022 – A new report from UN Climate Change shows countries are bending the curve of global greenhouse gas emissions downward but underlines that these efforts remain insufficient to limit global temperature rise to 1.5 degrees Celsius by the end of the century.
Loss and damage from climate change is already costing vulnerable communities dearly. These communities have played almost no role in causing the climate crisis, yet they are now paying for it with damaged and destroyed homes and schools, lost crops and livelihoods, and the loss of loved ones.

août 2022

Atmospheric soot loadings from nuclear weapon detonation would cause disruptions to the Earth’s climate, limiting terrestrial and aquatic food production. Here, we use climate, crop and fishery models to estimate the impacts arising from six scenarios of stratospheric soot injection, predicting the total food calories available in each nation post-war after stored food is consumed. In quantifying impacts away from target areas, we demonstrate that soot injections larger than 5 Tg would lead to mass food shortages, and livestock and aquatic food production would be unable to compensate for reduced crop output, in almost all countries. Adaptation measures such as food waste reduction would have limited impact on increasing available calories. We estimate more than 2 billion people could die from nuclear war between India and Pakistan, and more than 5 billion could die from a war between the United States and Russia—underlining the importance of global cooperation in preventing nuclear war.
Climate endgame is the name some scientists have given to the hypothesis of a global societal collapse due to effects of climate change. The real chance of happening is considered small, but the researchers who warned most resoundingly about this danger in August 2022 seek to improve risk management by putting a higher priority on worst-case scenarios, to "galvanise action, improve resilience, and inform policy".
Prudent risk management requires consideration of bad-to-worst-case scenarios. Yet, for climate change, such potential futures are poorly understood. Could anthropogenic climate change result in worldwide societal collapse or even eventual human extinction? At present, this is a dangerously underexplored topic. Yet there are ample reasons to suspect that climate change could result in a global catastrophe...

juillet 2022

Ce policy brief propose une série de recommandations et appelle au renforcement des connaissances en amont de l’implantation d’éoliennes en mer. Il prône une meilleure connaissance du fonctionnement des écosystèmes marins, des impacts cumulés des activités humaines existantes et des impacts sur le milieu marin du changement climatique, afin de guider la planification notamment dans le choix des zones d’implantation des éoliennes.