IPCC Climate Change 2023: The AR6 Synthesis Report

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Intergovernmental Panel on Climate Change | 2023

This Synthesis Report (SYR) constitutes the final product of the Sixth Assessment Report (AR6) of the Intergovernmental Panel on Climate Change (IPCC). It summarizes the state of knowledge of climate change, its widespread impacts and risks, and climate change mitigation and adaptation, based on the peer-reviewed scientific, technical, and socio-economic literature since the publication of the IPCC’s Fifth Assessment Report (AR5) in 2014.

This SYR distills, synthesizes, and integrates the key findings of the three Working Group contributions:
Climate Change 2021: The Physical Science Basis;
Climate Change 2022: Impacts, Adaptation and Vulnerability;
and Climate Change 2022: Mitigation of Climate Change.

The SYR also draws on the findings of three Special Reports completed as part of the Sixth Assessment:
Global Warming of 1.5°C (2018): an IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty (SR1.5);
Climate Change and Land (2019): an IPCC Special Report on climate change, desertification, land degradation, sustainable land management, food security, and greenhouse gas fluxes in terrestrial ecosystems (SRCCL);
and The Ocean and Cryosphere in a Changing Climate (2019) (SROCC).

The SYR, therefore, is a comprehensive, timely compilation of assessments of the most recent scientific, technical, and socio-economic literature dealing with climate change.

Scope of the report

The SYR is a self-contained synthesis of the most policy-relevant material drawn from the scientific, technical, and socio-economic literature assessed during the Sixth Assessment. This report integrates the main findings of the AR6 Working Group reports and the three AR6 Special Reports. It recognizes the interdependence of climate, ecosystems and biodiversity, and human societies; the value of diverse forms of knowledge; and the close linkages between climate adaptation, mitigation, ecosystem health, human well-being, and sustainable development. Building on multiple analytical frameworks, including those from the physical and social sciences, this report identifies opportunities for transformative action which are effective, feasible, just and equitable systems transitions, and climate resilient development pathways. Different regional classification schemes are used for physical, social and economic aspects, reflecting the underlying literature.

The Synthesis Report emphasizes near-term risks and options for addressing them to give policymakers a sense of the urgency required to address global climate change. The report also provides important insights about how climate risks interact with not only one another but non-climate-related risks. It describes the interaction between mitigation and adaptation and how this combination can better confront the climate challenge as well as produce valuable co-benefits. It highlights the strong connection between equity and climate action and why more equitable solutions are vital to addressing climate change. It also emphasizes how growing urbanization provides an opportunity for ambitious climate action to advance climate resilient development and sustainable development for all. And it underscores how restoring and protecting land and ocean ecosystems can bring multiple benefits to biodiversity and other societal goals, just as a failure to do so presents a major risk to ensuring a healthy planet.

Structure of the report

The SYR comprises a Summary for Policymakers (SPM) and a longer report from which the SPM is derived, as well as annexes.

To facilitate access to the findings of the SYR for a wide readership, each part of the SPM carries highlighted headline statements. Taken together, these 18 headline statements provide an overarching summary in simple, non-technical language for easy assimilation by readers from different walks of life.

The SPM follows a structure and sequence like that in the longer report, but some issues covered in more than one section of the longer report are summarized in a single location in the SPM. Each paragraph of the SPM contains references to the supporting text in the longer report. In turn, the longer report contains extensive references to relevant portions of the Working Group Reports or Special Reports mentioned above.

The longer report is structured around three topic headings as mandated by the Panel. A brief Introduction (Section1) is followed by three sections.

Section 2, ‘Current Status and Trends’, opens with the assessment of observational evidence for our changing climate, historical and current drivers of human-induced climate change, and its impacts. It assesses the current implementation of adaptation and mitigation response options.

Section 3, ‘Long-Term Climate and Development Futures’, provides an assessment of climate change to 2100 and beyond in a broad range of socio-economic futures. It considers long-term impacts, risks and costs in adaptation and mitigation pathways in the context of sustainable development.

Section 4, ‘Near-Term Responses in a Changing Climate’, assesses opportunities for scaling up effective action in the period to 2040, in the context of climate pledges, and commitments, and the pursuit of sustainable development.

Annexes containing a glossary of terms used, list of acronyms, authors, Review Editors, the SYR Scientific Steering Committee, and Expert Reviewers complete the report.

Process to build the report

The SYR was prepared in accordance with the procedures of the IPCC. A scoping meeting to develop a detailed outline of the AR6 Synthesis Report was held in Singapore from 21 to 23 October 2019 and the outline produced in that meeting was approved by the Panel at the 52nd IPCC Session from 24 to 28 February 2020 in Paris, France.

In accordance with IPCC procedures, the IPCC Chair, in consultation with the Co-Chairs of the Working Groups, nominated authors for the Core Writing Team (CWT) of the SYR. A total of 30 CWT members and 9 Review Editors were selected and accepted by the IPCC Bureau at its 58th Session on 19 May 2020. In the process of developing the SYR, 7 Extended Writing Team (EWT) authors were selected by the CWT and approved by the Chair and the IPCC Bureau, and 28 Contributing Authors were selected by the CWT with the approval of the Chair. These additional authors were to enhance and deepen the expertise required for the preparation of the Report. The Chair established at the 58th Session of the Bureau an SYR Scientific Steering Committee (SSC) with a mandate to advise the development of the SYR. The SYR SSC comprised the members of the IPCC Bureau, excluding those members who served as Review Editors for the SYR.

Due to the covid pandemic, the first two meetings of the CWT were held virtually from 25 to 29 January 2021 and from 16 to 20 August 2021. The First Order Draft (FOD) was released to experts and governments for review on 10 January 2022 with comments due on 20 March 2022. The CWT met in Dublin from 25 to 28 March 2022 to discuss how best to revise the FOD to address the more than 10,000 comments received. The Review Editors monitored the review process to ensure that all comments received appropriate consideration. The IPCC circulated a final draft of the Summary for Policymakers and a longer report of the SYR to governments for review from 21 November 2022 to 15 January 2023 which resulted in over 6,000 comments. A final SYR draft for approval incorporating the comments from the final government distribution was submitted to the IPCC member governments on 8 March 2023.

The Panel at its 58th Session, held from 13 to 17 March 2023 in Interlaken, Switzerland, approved the SPM line by line and adopted the longer report section by section.

Download here the IPCC Climate Change 2023: The AR6 Synthesis Report

Climate Change 2023: Synthesis Report is based on the assessments carried out by the three Working Groups of the IPCC and written by a dedicated Core Writing Team of authors. It provides an integrated assessment of climate change and addresses the following topics:

  • Current Status and Trends
  • Long-Term Climate and Development Futures
  • Near-Term Responses in a Changing Climate
    ISBN: 978-92-9169-164-7
    doi: 10.59327/IPCC/AR6-9789291691647

Source: The AR6 Synthesis Report of Climate Change 2023