IPCC opens meeting to approve physical science report

GENEVA, July 26 – The Intergovernmental Panel on Climate Change (IPCC) opened a meeting on Monday to approve its next report on the physical science basis of climate change, the first part of the Sixth Assessment Report.

The report, prepared by IPCC Working Group I, will provide the most up-to-date physical understanding of the climate system and climate change, bringing together the latest advances in climate science and multiple lines of evidence.

The meeting is being held remotely, the first time the IPCC has conducted an approval session in this format, from 26 July to 6 August 2021, because of the impact of the COVID-19 pandemic. Subject to the decisions of the Panel, the report will be released on 9 August.

“This report has been prepared in exceptional circumstances, and this is an unprecedented IPCC approval session,” IPCC Chair Hoesung Lee told the opening session of the meeting.

Lee thanked the 234 report authors for their commitment and determination to produce the report in the conditions of the pandemic.

“This work has required multiple series of virtual meetings across time zones, disrupting daily lives and work rhythms, especially in the most critical phase of the last 16 months as we shaped the final draft,” he said.

The report, Climate Change 2021: the Physical Science Basis,will provide the latest knowledge on past warming and future warming projections, showing how and why the climate has changed to date, and including an improved understanding of human influence on the climate including extreme events.

There will be a greater focus on regional information that can be used for climate risk assessments.

At the meeting the 14th Session of Working Group I will consider the Summary for Policymakers of the Working Group I contribution to the Sixth Assessment Report for approval in line-by-line scrutiny and the full report for acceptance. The 54th Session of the IPCC will then accept the work of Working Group I, formally accepting the report.

The aim of this process is to ensure that the Summary for Policymakers is accurate, well-balanced and presents the scientific findings of the underlying report clearly.

The approval plenary is the culmination of the rigorous process of drafting and review that IPCC reports undergo. The first-order draft of the Working Group I report received 23,462 review comments from 750 expert reviewers, the second-order draft received 51,387 review comments from governments and 1,279 experts, and the final government distribution of the Summary for Policymakers that ended on 20 June received over 3,000 comments from 47 governments. Over 14,000 scientific papers are referenced in the report.

The remaining parts of the Sixth Assessment Report will be finalized in 2022.

For more information, please contact:
IPCC Press Office, Email: ipcc-media@wmo.int  
Jonathan Lynn, +41 22 730 8066, Werani Zabula, +41 22 730 8120

Notes for Editors

 About the IPCC

The Intergovernmental Panel on Climate Change (IPCC) is the UN body for assessing the science related to climate change. It was established by the United Nations Environment Programme (UNEP) and the World Meteorological Organization (WMO) in 1988 to provide political leaders with periodic scientific assessments concerning climate change, its implications and risks, as well as to put forward adaptation and mitigation strategies. In the same year the UN General Assembly endorsed the action by the WMO and UNEP in jointly establishing the IPCC. It has 195 member states.

Thousands of people from all over the world contribute to the work of the IPCC. For the assessment reports, IPCC scientists volunteer their time to assess the thousands of scientific papers published each year to provide a comprehensive summary of what is known about the drivers of climate change, its impacts and future risks, and how adaptation and mitigation can reduce those risks.

The IPCC has three working groups: Working Group I, dealing with the physical science basis of climate change; Working Group II, dealing with impacts, adaptation and vulnerability; and Working Group III, dealing with the mitigation of climate change. It also has a Task Force on National Greenhouse Gas Inventories that develops methodologies for measuring emissions and removals.

IPCC assessments provide governments, at all levels, with scientific information that they can use to develop climate policies. IPCC assessments are a key input into the international negotiations to tackle climate change. IPCC reports are drafted and reviewed in several stages, thus guaranteeing objectivity and transparency.

About the Sixth Assessment Cycle

Comprehensive scientific assessment reports are published every 6 to 7 years; the latest, the Fifth Assessment Report, was completed in 2014 and provided the main scientific input to the Paris Agreement. 

At its 41st Session in February 2015, the IPCC decided to produce a Sixth Assessment Report (AR6). At its 42nd Session in October 2015 it elected a new Bureau that would oversee the work on this report and Special Reports to be produced in the assessment cycle. At its 43rd Session in April 2016, it decided to produce three Special Reports, a Methodology Report and AR6. 

The IPCC also publishes special reports on more specific issues between assessment reports.

Global Warming of 1.5°C, an IPCC special report on the impacts of global warming of 1.5 degrees Celsius 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 was launched in October 2018.

Climate Change and Land, an IPCC special report on climate change, desertification, land degradation, sustainable land management, food security, and greenhouse gas fluxes in terrestrial ecosystems was launched in August 2019, and the Special Report on the Ocean and Cryosphere in a Changing Climate was released in September 2019.

In May 2019 the IPCC released the 2019 Refinement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories, an update to the methodology used by governments to estimate their greenhouse gas emissions and removals. 

The contributions of the three IPCC Working Groups to the Sixth Assessment Report are currently under preparation. The concluding Synthesis Report is due in 2022.

For more information visit www.ipcc.ch.

The website includes outreach materials including videos about the IPCC and video recordings from outreach events conducted as webinars or live-streamed events.

Most videos published by the IPCC can be found on our YouTube and Vimeo channels.