GENEVA, Mar 24 – Over 100 experts from more than 40 countries are meeting in Bilbao, Spain this week for the first meeting of authors and review editors of the 2027 IPCC Methodology Report on Inventories for Short-lived Climate Forcers (SLCF). This will be the first report released by IPCC in the seventh assessment cycle and it is being prepared by the Task Force on National Greenhouse Gas Inventories (TFI).
The 2027 Methodology Report is expected to provide guidance on anthropogenic emissions for Short-lived Climate Forcers, not including secondary human-induced substances.
“The report aims to provide clear guidance on measuring emissions from key short-lived climate forcing substances, including nitrogen oxides, carbon monoxide, and others, which significantly contribute to global and regional air quality and climate change,” said Takeshi Enoki, one of the Co-Chairs of the TFI.
This week´s meeting in Bilbao marks the beginning of the drafting process of this Methodology Report which is scheduled to be released in March 2027. The Coordinating Lead Authors and Lead Authors at this meeting will start developing the report based on the outline agreed by the Panel during its 61st Session held in Sofia, Bulgaria in July/August 2024.
“We are excited to begin work on this report with a diverse group of experts selected from the 394 nominations we received. Their work will be important for enhancing the data used in climate models,” said Mazhar Hayat, TFI Co-Chair.
Following the Panel’s 61st Session, the IPCC called for nominations of experts to act as Authors and Review Editors of the 2027 Methodology Report in August 2024. The TFI Bureau, also known as the Task Force Bureau, in consultation with relevant Working Group Co-Chairs selected the report’s Coordinating Lead Authors, Lead Authors and Review Editors. In their selection, they considered scientific and technical expertise, geographical and gender balance in line with Appendix A to the Principles Governing IPCC Work.
A preliminary list of the Authors for the 2027 Methodology Report is available here.
Following the Lead Author Meeting, there will be an outreach event hosted by the Spanish Climate Change Office at the Bizkaia Aretoa in Bilbao on 27 March 2025. More details on the event are available here.
For more information, contact:
IPCC Press Office, Email: ipcc-media@wmo.int;
Andrej Mahecic, +41 22 730 8516; Werani Zabula, +41 22 730 8120.
Notes for Editors
What is 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, scientists and experts volunteer their time as IPCC authors 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 Seventh Assessment Cycle
Comprehensive scientific assessment reports are published every 5 to 7 years. The IPCC is currently in its seventh assessment cycle, which formally began in July 2023 with the elections of the new IPCC and Task Force Bureaus at the IPCC’s Plenary Session in Nairobi.
At its first Plenary Session in the seventh assessment cycle – the 60th Plenary Session in Istanbul, Türkiye, in January 2024 – the Panel agreed to produce in this cycle the three Working Group contributions to the Seventh Assessment Report (AR7), namely the Working Group I report on the Physical Science Basis, the Working Group II report on Impacts, Adaptation and Vulnerability and the Working Group III report on Mitigation of Climate Change. The Synthesis Report of the Seventh Assessment Report will be produced after the completion of the Working Group reports and released by late 2029.
During its 62nd Plenary Session held in Hangzhou, China, in February 2025, the Panel has agreed on the outlines of the three Working Group contributions to the Seventh Assessment Report (AR7).
The Panel decided already during the previous cycle to produce a Special Report on Climate Change and Cities and a Methodology Report on Short-lived Climate Forcers during AR7.. Scientists have also been asked to deliver a Methodology Report on Carbon Dioxide Removal Technologies, Carbon Capture Utilization and Storage.
At the IPCC’s 61st Plenary Session held in Sofia, Bulgaria, from 27 July to 2 August 2024, the Panel agreed upon the outlines for the Special Report on Climate Change and Cities scheduled for approval and publication in March 2027 and for the 2027 IPCC Methodology Report on Inventories for Short-lived Climate Forcers scheduled for publication in the second half 2027.
In addition, a revision of the 1994 IPCC Technical Guidelines on impacts and adaptation as well as adaptation indicators, metrics and guidelines, will be developed in conjunction with the Working Group II report and published as a separate product.
IPCC’s latest report, the Sixth Assessment Report, was completed in March 2023 with the release of its Synthesis Report, which provided direct scientific input to the First Global Stocktake process under the United Nations Framework Convention on Climate Change at COP28 in Dubai.
The Sixth Assessment Report comprises three Working Group contributions and a Synthesis Report. The Working Group I contribution Climate Change 2021: the Physical Science Basis was released on 9 August 2021. The Working Group II contribution, Climate Change 2022: Impacts, Adaptation and Vulnerability, was released on 28 February 2022. The Working Group III contribution, Climate Change 2022: Mitigation of Climate Change, was released on 4 April 2022 and the Synthesis Report on 20 March 2023. The Synthesis Report to the Sixth Assessment Report, distils and integrates the findings of the three Working Group assessments as well as the three Special Reports released in 2018 and 2019.
The special reports were on Global Warming of 1.5°C (October 2018.), Climate Change and Land (August 2019) and, the Ocean and Cryosphere in a Changing Climate (September 2019).
For more information visit www.ipcc.ch.
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