Quelles transitions pour l’atténuation du changement climatique ? Transformations globales, enjeux sociétaux, et leçons pour la décision

The IPCC Special report on “Global Warming of 1.5 °C” identifies the greenhouse gas emissions trajectories compatible with the global mitigation goal of the Paris Agreement, presents the mitigation actions required to follow these trajectories and analyses the synergies and trade-offs with sustainable development objectives. The assessment highlights the necessity to implement drastic global carbon emissions reductions in the short term, to reach global carbon neutrality between 2050 and 2070 and to implement targeted actions to limit other greenhouse gases. To this aim, rapid and far-reaching transformations are required in energy, industrial, infrastructure and land-use systems. Adopting systemic strategies combining policy packages elaborated according to the specificities of each country context and with a long-term perspective is a requirement for ensuring that these low-emission transformations can be compatible with the achievement of socio-economic and development objectives

Quelles transitions pour l’atténuation du changement climatique ? Transformations globales, enjeux sociétaux, et leçons pour la décision

The IPCC Special report on “Global Warming of 1.5 °C” identifies the greenhouse gas emissions trajectories compatible with the global mitigation goal of the Paris Agreement, presents the mitigation actions required to follow these trajectories and analyses the synergies and trade-offs with sustainable development objectives. The assessment highlights the necessity to implement drastic global carbon emissions reductions in the short term, to reach global carbon neutrality between 2050 and 2070 and to implement targeted actions to limit other greenhouse gases. To this aim, rapid and far-reaching transformations are required in energy, industrial, infrastructure and land-use systems. Adopting systemic strategies combining policy packages elaborated according to the specificities of each country context and with a long-term perspective is a requirement for ensuring that these low-emission transformations can be compatible with the achievement of socio-economic and development objectives

Towards a Better Understanding of Disparities in Scenarios of Decarbonization: Sectorally Explicit Results from the RECIPE Project

This paper presents results from a model intercomparison exercise among regionalized global energy-economy models conducted in the context of the RECIPE project. The economic adjustment effects of long-term climate policy aiming at stabilization of atmospheric CO2 concentrations at 450 ppm are investigated based on the cross-comparison of the intertemporal optimization models REMIND-R and WITCH as well as the recursive dynamic computable general equilibrium model IMACLIM-R. The models applied in the project differ in several respects and the comparison exercise tracks differences in the business as usual forecasts as well as in the mitigation scenarios to conceptual differences in the model structures and assumptions. In particular, the models have different representation of the sectoral structure of the energy system. A detailed sectoral analysis conducted as part of this study reveals that the sectoral representation is a crucial determinant of the mitigation strategy and costs. While all models project that the electricity sector can be decarbonized readily, emissions abatement in the non-electric sectors, particularly transport, is much more challenging. Mitigation costs and carbon prices were found to depend strongly on the availability of low-carbon options in the non-electric sectors.Decarbonization, Energy and Climate Policy

IMACLIM-R: a modelling framework to simulate sustainable development pathways

To assess the sustainability of future development pathways requires models to compute long-run Economy-Energy-Environment scenarios. This paper presents the IMACLIM-R framework, aimed at investigating climate, energy and development inter-related issues. The model was built in an attempt to address three methodological challenges: to incoporate knowledge from economics and engineering sciences, to support the dialogue with and between stakeholders, to produce scenarios with a strong consistency, concerning especially the interplay between development patterns, technology and growth. These goals led to the development of a recursive structure articulating a static general equilibrium framework including innovative features and sectorspecific dynamic modules now concerning energy, transportation and industry. This paper provides the general rationale of the model and the description of all its components.

IMACLIM-R: a modelling framework to simulate sustainable development pathways

International audienceTo assess the sustainability of future development pathways requires models to compute long-run Economy-Energy-Environment scenarios. This paper presents the IMACLIM-R framework, aimed at investigating climate, energy and development inter-related issues. The model was built in an attempt to address three methodological challenges: to incoporate knowledge from economics and engineering sciences, to support the dialogue with and between stakeholders, to produce scenarios with a strong consistency, concerning especially the interplay between development patterns, technology and growth. These goals led to the development of a recursive structure articulating a static general equilibrium framework including innovative features and sectorspecific dynamic modules now concerning energy, transportation and industry. This paper provides the general rationale of the model and the description of all its components

Climate policies as a hedge against the uncertainty on future oil supply

International audienceDespite the inextricable link between oil scarcity and climate change, the interplay between these two issues is paradoxically an underworked area. This article uses a global energy-economy model to address the link between future oil supply and climate change and assesses in a common framework both the costs of climate policies and oil scarcity. It shows that, in the context of a limited and uncertain amount of ultimately recoverable oil resources, climate policies reduce the world vulnerability to peak oil. Climate policies, therefore, appear as a hedging strategy against the uncertainty on oil resources, in addition to their main aim of avoiding dangerous climate change. This co-benefit is estimated at the net present value of US$11,500 billion. Eventually, reducing the risk of future economic losses due to oil scarcity may appear as a significant side-benefit of climate policies to many decision-makers

Special Report on Global warming of 1.5°C (SR15) - Chapter 5:Sustainable Development, Poverty Eradication and Reducing Inequalities

The Special Report on 1.5°C assesses three main themes: • What would be required to limit warming to 1.5°C (mitigation pathways) • The impacts of 1.5°C of warming, compared to 2ºC and higher • Strengthening the global response to climate change; mitigation and adaptation options The connections between climate change and sustainable development and efforts to eradicate poverty are discussed throughout the report. This chapter takes sustainable development as the starting point and focus for analysis. It considers the broad and multifaceted bi-directional interplay between sustainable development, including its focus on eradicating poverty and reducing inequality in their multidimensional aspects, and climate actions in a 1.5°C warmer world. These fundamental connections are embedded in the Sustainable Development Goals (SDGs). The chapter also examines synergies and trade-offs of adaptation and mitigation options with sustainable development and the SDGs and offers insights into possible pathways, especially climate-resilient development pathways towards a 1.5°C warmer world

Les clés d’une négociation planétaire. Quelle prise en compte de la justice climatique ?

National audienceL’Accord de Paris entérine une nouvelle approche de la justice climatique dans les négociations internationales sur le climat par rapport à celle qui a prévalu jusqu’à Copenhague. Ainsi, les discussions ne sont plus ancrées sur le principe de "partage du fardeau", qui se heurte à la question du critère d’équité à utiliser pour répartir les efforts. Le processus qui a conduit à Paris a, lui, été construit autour des contributions nationales reflétant la vision domestique des transitions bas-carbone articulées avec les besoins du pays en matière de développement socio-économique. Dans cette approche bottom-up, la justice climatique passe notamment par les mécanismes de coopération internationale requis pour accompagner et soutenir collectivement les transitions nationales compatibles avec l’objectif des +2°C. Pour informer ce processus, les trajectoires menant à la décarbonation des économies doivent satisfaire trois conditions: i) considérer le long-terme pour assurer les exigences de réductions d’émissions telles qu’évaluées par le GIEC, ii) intégrer explicitement les spécificités sociales, économiques, physiques... du contexte et iii) être transparentes, c’est-à-dire révéler les sous-jacents concrets de la transformation. Le Deep Decarbonization Pathways Project (DDPP) a mis en œuvre ces principes pour définir et analyser des trajectoires de décarbonisation profonde dans 16 pays, parmi les plus gros émetteurs de gaz à effet de serre. Cette étude permet d’identifier les sous-jacents des transformations à mettre en œuvre et les axes cruciaux de coopération pour les rendre possibles

Systèmes urbains et politiques climatiques

International audienc