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Les pays du monde entier se trouvent à un moment critique de la bataille contre la pollution plastique. Alors que les négociations autour d’un traité mondial sur les matières plastiques touchent à leur fin, l’OCDE présente, dans ce rapport, les résultats d’un exercice de modélisation de scénarios d’action fondés sur différents types d’intervention : limiter la production et la demande, promouvoir l’écoconception, augmenter le recyclage et fermer les voies de rejet. Ce rapport éclaire sur les avantages environnementaux et les conséquences économiques qui pourraient découler des actions engagées pour mettre fin à la pollution par les plastiques d’ici à 2040, selon différents niveaux d’ambition : quels pays agissent, le caractère rigoureux des mesures et les phases du cycle de vie des plastiques auxquelles elles s'appliquent.

Previous health impact assessments of temperature-related mortality in Europe indicated that the mortality burden attributable to cold is much larger than for heat. Questions remain as to whether climate change can result in a net decrease in temperature-related mortality. In this study, we estimated how climate change could affect future heat-related and cold-related mortality in 854 European urban areas, under several climate, demographic and adaptation scenarios. We showed that, with no adaptation to heat, the increase in heat-related deaths consistently exceeds any decrease in cold-related deaths across all considered scenarios in Europe. Under the lowest mitigation and adaptation scenario (SSP3-7.0), we estimate a net death burden due to climate change increasing by 49.9% and cumulating 2,345,410 (95% confidence interval = 327,603 to 4,775,853) climate change-related deaths between 2015 and 2099. This net effect would remain positive even under high adaptation scenarios, whereby a risk attenuation of 50%

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...

Avec le 6ème rapport d’évaluation du Groupe d'experts intergouvernemental sur l'évolution du climat (GIEC), une nouvelle génération de scénarios climatiques permet de mieux appréhender les futurs possibles en termes de dérive climatique. Les scénarios dits SSP (Shared Socio-economic Pathways) viennent remplacer les scénarios dits RCP (Representative Concentration Pathways).

1.5 °C scenarios reported by the Intergovernmental Panel on Climate Change (IPCC) rely on combinations of controversial negative emissions and unprecedented technological change, while assuming continued growth in gross domestic product (GDP). Thus far, the integrated assessment modelling community and the IPCC have neglected to consider degrowth sce- narios, where economic output declines due to stringent climate mitigation. Hence, their potential to avoid reliance on negative emissions and speculative rates of technological change remains unexplored. As a first step to address this gap, this paper compares 1.5 °C degrowth scenarios with IPCC archetype scenarios, using a simplified quantitative repre- sentation of the fuel-energy-emissions nexus.

1.5 °C degrowth scenarios suggest the need for new mitigation pathways

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A novel methodology is developed to dynamically assess the energy and material investments required over time to achieve the transition from fossil fuels to renewable energy sources in the electricity sector. The obtained results indicate that a fast transition achieving a 100% renewable electric system globally by 2060 consistent with the Green Growth narrative could decrease the EROI of the energy system from current ~12:1 to ~3:1 by the mid-century, stabilizing thereafter at ~5:1. These EROI levels are well below the thresholds identified in the literature required to sustain industrial complex societies. Moreover, this transition could drive a substantial re-materialization of the economy, exacerbating risk availability in the future for some minerals. Hence, the results obtained put into question the consistence and viability of the Green Growth narrative.

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