Measures to enhance the effectiveness of international climate agreements: The case of border carbon adjustments

Actions on climate change which are not supported by all countries are not very effective. However, full participation in a global climate treaty with meaningful emission reductions is difficult to achieve. The non-excludability of the public good mitigation provides an incentive to abstain from global action. Moreover, carbon leakage renders it unattractive to join a treaty without full participation. We study whether and under which conditions border carbon adjustments (BCAs) can mitigate free-riding and reduce carbon leakage in a simple strategic trade model. We show that BCAs can lead to large stable climate agreements, including full participation, associated with large global welfare gains if treaties do not restrict membership (open membership), as this is typical for environmental agreements. We caution against restricting accession to treaties (exclusive membership), as this is typical for trade agreements, which may serve individual but not global interests

Summary for Policymakers

The Working Group III (WGIII) contribution to the IPCC’s Sixth Assessment Report (AR6) assesses literature on the scientific, technological, environmental, economic and social aspects of mitigation of climate change.The report reflects new findings in the relevant literature and builds on previous IPCC reports, including the WGIII contribution to the IPCC’s Fifth Assessment Report (AR5), the WGI and WGII contributions to AR6 and the three Special Reports in the Sixth Assessment cycle, as well as other UN assessments

Implementation of FAIR principles in the IPCC: the WGI AR6 Atlas repository

The Sixth Assessment Report (AR6) of the Intergovernmental Panel on Climate Change (IPCC) has adopted the FAIR Guiding Principles. We present the Atlas chapter of Working Group I (WGI) as a test case. We describe the application of the FAIR principles in the Atlas, the challenges faced during its implementation, and those that remain for the future. We introduce the open source repository resulting from this process, including coding (e.g., annotated Jupyter notebooks), data provenance, and some aggregated datasets used in some figures in the Atlas chapter and its interactive companion (the Interactive Atlas), open to scrutiny by the scientific community and the general public. We describe the informal pilot review conducted on this repository to gather recommendations that led to significant improvements. Finally, a working example illustrates the re-use of the repository resources to produce customized regional information, extending the Interactive Atlas products and running the code interactively in a web browser using Jupyter notebooks.Peer reviewe

Innovations for Sustainability: Pathways to an efficient and post-pandemic future

3rd Report prepared by The World in 2050 initiativ

Intergovernmental Panel on Climate Change: transparency and integrated assessment modeling

Integrated assessment models (IAMs) connect trends in future socioeconomic and technological development with impacts on the environment, such as global climate change. They occupy a critical position at the global science-policy interface. IAMs and associated scenarios have come under intense scrutiny, with critiques addressing both methodological and substantive issues, such as land use, carbon dioxide removal and technology performance. Criticisms have also addressed the transparency of IAM methods and assumptions as well as the transparency of the Intergovernmental Panel on Climate Change (IPCC) assessment of IAMs. This paper, authored by the co-chairs of IPCC Working Group III and members of the Technical Support Unit, documents activities aiming to enhance the transparency of IAMs and their assessment. It includes a history of IPCC's approach to scenarios covering the formation of the Integrated Assessment Modeling Consortium (IAMC) in 2007 and the emergence of the approach by which IPCC facilitates the development of scenarios, but does not produce them itself. An IPCC Expert Meeting at the start of the current assessment cycle made transparency recommendations targeted at both the research community and IPCC. The community has taken steps to “open the black box” by moving toward open-source and web-publishing IAM documentation. IPCC has included an Annex to its next report focusing on scenarios and modeling methodologies. An open call for scenario data linked to the current IPCC report includes an expanded set of input and output variables. This paper ends with suggested criteria for measuring the success of these efforts to improve transparency

Little room for new fossil fuel development if global temperatures are to stay below 1.5 degrees C

A new paper in Nature by Welsby et al. makes clear that pursuing efforts to limit global average temperature increase to 1.5°C above pre-industrial levels—the most frequently stated goal of the 2015 Paris Agreement—implies the vast majority of coal, crude oil, and natural gas must remain underground and undeveloped

Outlooks, explorations and normative scenarios: approaches to global energy futures compared

This paper compares recent global energy scenarios developed by governments, international bodies, businesses and the scientific community. We divide the scenarios into three broad classes: outlooks which extrapolate current trends and anticipate policy developments; exploratory scenarios which may consider disruptions; and normative scenarios which derive energy system pathways consistent with a long-term goal. Many organisations are starting to blend outlooks, exploratory and normative approaches. The paper covers trends in primary energy demand to 2040, snapshots of the energy mix in 2040, drivers of demand, and the evolution of scenarios projections developed in recent years. We find sharp divergences between outlooks and normative scenarios compatible with the Paris Agreement on climate change. All published outlooks imply that the world is not on an energy pathway compatible with the Paris Agreement. We conclude with an assessment of emerging themes including: scenario benchmarking and group think; adaptation of scenarios to real world developments; and the plausibility of different types of scenarios. We propose that more dialogue between scenario developers from the scientific community and those working in governments and commercial organisations could be beneficial. Research focusing on the organisational processes through which scenarios are developed could usefully extend this work

NGFS Climate Scenarios Data Set Version 3.0

This dataset contains a set of climate scenario that have been developed for the Network for Greening the Financial System (NGFS). The NGFS is a group of 83 central banks and supervisors and 12 observers committed to sharing best practices, contributing to the development of climate– and environment–related risk management in the financial sector and mobilising mainstream finance to support the transition toward a sustainable economy. The scenarios in this dataset were produced by NGFS Workstream 3 in partnership with an academic consortium from the Potsdam Institute for Climate Impact Research (PIK), International Institute for Applied Systems Analysis (IIASA), University of Maryland (UMD), Climate Analytics (CA), the Eidgenössische Technische Hochschule Zürich (ETH) and the National Institute of Economic and Social Research (NIESR). The Phase 3 bespoke scenarios are generated by state-of-the-art well-established integrated assessment models (IAMs), namely GCAM, MESSAGEix-GLOBIOM and REMIND-MAgPIE. These models allow the estimation of global and regional mitigation costs, the analysis of energy system transition characteristics, the quantification of investments required to transform the energy system, and the identification of synergies and trade-off of sustainable development pathways. Technical documentation is available to help users access the datasets. The documentation describes the models and variables, as well as provides detailed guidance for database users. Scenario presentation materials and the user guide are also available at the NGFS portal

NGFS Climate Scenarios Data Set Version 4.0

This dataset contains a set of climate scenario that have been developed for the Network for Greening the Financial System (NGFS). The NGFS is a group of 83 central banks and supervisors and 12 observers committed to sharing best practices, contributing to the development of climate– and environment–related risk management in the financial sector and mobilising mainstream finance to support the transition toward a sustainable economy. The scenarios in this dataset were produced by NGFS Workstream 3 in partnership with an academic consortium from the Potsdam Institute for Climate Impact Research (PIK), International Institute for Applied Systems Analysis (IIASA), University of Maryland (UMD), Climate Analytics (CA), the Eidgenössische Technische Hochschule Zürich (ETH) and the National Institute of Economic and Social Research (NIESR). The Phase 3 bespoke scenarios are generated by state-of-the-art well-established integrated assessment models (IAMs), namely GCAM, MESSAGEix-GLOBIOM and REMIND-MAgPIE. These models allow the estimation of global and regional mitigation costs, the analysis of energy system transition characteristics, the quantification of investments required to transform the energy system, and the identification of synergies and trade-off of sustainable development pathways. Technical documentation is available to help users access the datasets. The documentation describes the models and variables, as well as provides detailed guidance for database users. Scenario presentation materials and the user guide are also available at the NGFS portal