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Under current emission trajectories, temporarily overshooting the Paris global warming limit of 1.5 °C is a distinct possibility. Permanently exceeding this limit would substantially increase the probability of triggering climate tipping elements. Here, we investigate the tipping risks associated with several policy-relevant future emission scenarios, using a stylised Earth system model of four interconnected climate tipping elements. We show that following current policies this century would commit to a 45% tipping risk by 2300 (median, 10–90% range: 23–71%), even if temperatures are brought back to below 1.5 °C. We find that tipping risk by 2300 increases with every additional 0.1 °C of overshoot above 1.5 °C and strongly accelerates for peak warming above 2.0 °C. Achieving and maintaining at least net zero greenhouse gas emissions by 2100 is paramount to minimise tipping risk in the long term. Our results underscore that stringent emission reductions in the current decade are critical for planetary stabili

A new record high, but is there light at the end of the tunnel?

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

Alors que les émissions de particules à l’échappement des transports routiers ont très nettement baissé avec la généralisation des filtres à particules, celles hors échappement provenant de l’abrasion des freins, des pneumatiques et des chaussées deviennent prépondérantes. L’ADEME, à partir des données de la bibliographie et des résultats de projets de recherche qu’elle a financés, a dressé un état des connaissances sur : Les particules d’abrasion des freins, des pneus et de la chaussée avec leurs caractéristiques, leurs compositions et les quantités émises Les solutions technologiques pour les réduire Leur impact sanitaire et environnemental Le volet réglementaire

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).

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

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.

Following record-level declines in 2020, near-real-time data indicate that global CO2 emissions rebounded by 4.8% in 2021, reaching 34.9 GtCO2. These 2021 emissions consumed 8.7% of the remaining carbon budget for limiting anthropogenic warming to 1.5 °C, which if current trajectories continue, might be used up in 9.5 years at 67% likelihood.

Measures implemented this year could bring down gas imports from Russia by over one-third, with additional temporary options to deepen these cuts to well over half while still lowering emissions.

Satisfying the increased demand for food is placing pressure on the world’s water, land and soil resources. Agriculture has its part to play in alleviating these pressures and contributing positively to climate and development goals. Sustainable agricultural practices can lead to direct improvements in the state of land, soil and water, and generate ecosystem benefits as well as reduce emissions from land. Accomplishing all these requires accurate information and a major change in how we manage the resources. It also requires complementing efforts from outside the natural resources management domain to maximize synergies and manage trade-offs.

World leaders must commit to boosting cycling levels to reduce carbon emissions and reach global climate goals quickly and effectively

In Paris, all governments solemnly promised to come to COP26 with more ambitious 2030 commitments to close the massive 2030 emissions gap that was already evident in 2015. Three years later the IPCC Special Report on 1.5°C reinforced the scientific imperative, and earlier this year it called a climate “code red.” Now, at the midpoint of Glasgow, it is clear there is a massive credibility, action and commitment gap that casts a long and dark shadow of doubt over the net zero goals put forward by more than 140 countries, covering 90% of global emissions.

Plateforme Wallonne / GIEC - Septembre 2021 - n°22 Les émissions associées à l’alimentation représentent de l’ordre de 1/4 à 1/3 des émissions de gaz à effet de serre mondiales. Le premier article de cette Lettre synthétise les connaissances à propos de l’origine de ces émissions et des moyens de les réduire. Comme la stratégie que s’est fixée l’Union européenne sous le titre « De la ferme à la table », nous avons tenté d’aborder l’ensemble des systèmes alimentaires, de la production à la consommation.

Table des émissions cumulatives de CO2 par pays et années

Plug gaps to measure ozone-destroying chemicals and greenhouse gases and verify compliance with Paris and Montreal treaties.

La neutralité climatique introduite à l’article 4 de l’accord de Paris s’applique à l’échelle de la planète. Elle vise à équilibrer les rejets anthropiques de gaz à effet de serre et leur élimination par les puits. Autrement dit, à atteindre une situation « ZEN » (« Zéro Emissions Nettes ») dans laquelle le flux des émissions entrant dans l’atmosphère s’équilibre avec celui qui s’en échappe.

Today, the average global temperature has increased by more than 1°C compared to pre-industrial values (Figure 1-1); atmospheric CO2 concentrations have risen from 280 to more than 400 ppm. At the current pace of emissions, the carbon budget that is left for staying below the 2°C target of the Paris Agreement will be depleted in a few tens of years. For the 1.5°C target, this budget will be exhausted before the decade is out.

The growing threat of abrupt and irreversible climate changes must compel political and economic action on emissions.