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The IPCC Working Group I (WG I) aims at assessing the physical scientific basis of the climate system and climate change. Its main topics include: changes in greenhouse gases and aerosols in the atmosphere; observed changes in air, land and ocean temperatures, rainfall, glaciers and ice sheets, oceans and sea level; historical and paleoclimatic perspective on climate change; biogeochemistry, carbon cycle, gases and aerosols; satellite data and other data; climate models; climate projections, causes and attribution of climate change.








Latest news: IPCC Special Report on Global Warming of 1.5°C

Expert Review of the First Order Draft and start of the Third Lead Author Meeting

MALMÖ, Oct 23 - Nearly 500 experts from around the world took part in the recent review of the First Order Draft of the Intergovernmental Panel on Climate Change (IPCC) Special Report on Global Warming of 1.5°C (SR15). At a meeting in Malmð, Sweden, this week, the authors will work on addressing nearly 13,000 comments from expert reviewers in 61 countries as they prepare the Second Order Draft.

The Third Lead Author Meeting for the Special Report on Global Warming of 1.5°C is being held in Malmð at the kind invitation of the Swedish government. The meeting is being hosted by the Swedish Meteorological and Hydrological Institute (SMHI) and taking place at MalmõMässan from 23-27 October 2017.

This week's meeting marks the culmination of the first round of expert review of the draft report: Global Warming of 1.5°C: 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.

Key statistics

  • Two thousand experts from 124 different countries registered to be reviewers (based on citizenship)
  • Overall, the First Order Draft of the Special Report on 1.5°C attracted 12,895 review comments.
  • These comments came from 489 expert reviewers representing 61 different countries.
  • Based on citizenship, half of expert reviewers were from Europe (51%). North America, Central America and the Caribbean accounted for a further 19%, Asia (13%), South America (7%), South West Pacific (6%) and Africa (5%).
  • A third (31%) of expert reviewers were female, two thirds (69%) were male.
  • Three quarters of reviewers (77%) were citizens of developed countries, 23% of developing countries.
  • Chapter 3 on impacts of 1.5°C global warming on natural and human systems attracted the most review comments (3,894, 30% of total comments). See full breakdown below.

All IPCC reports go through two stages of formal review. Feedback received in the first round of expert review will be incorporated, as appropriate, by the authors into the Second Order Draft. The Second Order Draft will then be open for review by governments and experts around the world from 8 January to 25 February 2018. The final report is due to be finalised and made publicly available in October 2018.

"The Second Order Draft will include a first version of the Summary for Policymakers (SPM), which is a distillation of the most policy-relevant findings from each chapter. Governments have asked us for a very concise SPM this time (about 10 pages)," said Valérie Masson-Delmotte, WGI Co-Chair.

The IPCC's comprehensive review process ensures that the reports cover the most up-to-date scientific, technical and socio-economic findings, and are representative of a broad range of independent expertise from developed and developing countries.

"An indicator of success for the IPCC process is the involvement of the scientists worldwide. Having about five times more expert reviewers than authors and nearly 13,000 comments is crucial. There is not a single section, table or figure that did not receive any comments," said Masson-Delmotte.

Of the 86 experts from 39 countries selected by the members of all three IPCC Working Groups in February to be authors of the Special Report on 1.5°C, 38% are women, 51% come from developing countries and economies in transition (based on citizenship) and 26% are new to the IPCC process.

The IPCC Special Report on Global Warming of 1.5°C is being prepared in response to an invitation from the 21st Conference of the Parties (COP21) to the United Nations Framework Convention on Climate Change. The report will be wide-ranging, assessing possible ways for limiting global warming to 1.5°C, as well as considering these issues in the broader context of sustainable development. More details are available on the report page.

The Special Report on Global Warming of 1.5°C is part of the IPCC's sixth assessment cycle. This cycle will produce three Special Reports, a Methodology Report on national greenhouse gas inventories and the Sixth Assessment Report (AR6), consisting of contributions from Working Groups I, II and III and a Synthesis Report.










IPCC calls for nominations of authors for the Sixth Assessment Report
The deadline for the nominations is Friday 27th October 2017 midnight GMT+1


The Intergovernmental Panel on Climate Change (IPCC), the UN body for assessing the science related to climate change, is calling for nominations of authors for the Sixth Assessment Report (AR6).

"We are seeking scientists with expertise across the disciplines assessed by the IPCC," said Hoesung Lee, Chair of the IPCC. "We also hope that more scientists from developing countries and more women scientists will be nominated as IPCC authors to give us diverse author teams that can provide a range of relevant perspectives."

The report outline consists of chapters with indicative bullets, listing topics to be considered in the assessment. Expertise is sought in the call for nominations to undertake the assessment of these topics.

To view the detailed chapter outlines of the WGI report:

How To Apply

To apply you will need to fill in the nomination form and provide a short (4 page max.) CV that needs to be submitted via the your national focal point or an observer organisation.

The nomination form asks for information about the candidate (including highest degree, sector, past IPCC experience and areas of expertise). Candidates are requested to select a maximum of three chapters from the report outline that they wish to contribute, and indicate which role they volunteer for (Coordinating Lead Author, Lead Author or Review Editor). Finally, candidates can list a maximum of three most relevant scientific publications. The nomination forms should be accompanied by an up-to-date CV (4 pages maximum).

Nomination Form: WGI_AR6_Nomination.xlsx

IPCC WGI Nomination Factsheet: IPCC WGI Nomination Factsheet.pdf

Focal Points:

Observer Organisations:

For more information, contact:

WGI Technical Support Unit











SR1.5 Expert Review of the First Order Draft


The Expert Review of the IPCC Special Report on Global Warming of 1.5°C (SR15) First Order Draft (FOD) will take place from 31 July to 24 September 2017. To register as an Expert Reviewer please complete the registration form via the dedicated website:

The expert review of draft reports is a central component of the IPCC assessment process that aims to ensure that the Report represents scientific findings comprehensively and in a balanced way, as judged by a very broad range of experts. Expert Reviewers can play an important role in identifying the key literature, ensuring a balanced interpretation and placing topics in context. The SR15 Lead Authors will consider all review comments on the FOD.

Registration will be available from 17 July 2017 and will close a week before the review ends, on the 17 September 2017. All review comments must be uploaded on or before Sunday, 24 September 2017.

More information on the expert review process is available in the guidance note

Please direct any technical questions on the review process to the WGI Technical Support Unit at .














SR1.5 Second Lead Author Meeting, Exeter, United Kingdom


The Second Lead Author Meeting for the Special Report on Global Warming on 1.5°C was hosted by the UK Met Office (Day 1) and the University of Exeter (days 2 to 5) from 5 to 9 June 2017, in Exeter, United Kingdom with the very kind funding of the University of Exeter and the support of the UK Met Office.














AR6 Scoping Meeting, Addis Ababa, Ethiopia


The meeting to draft the outlines of each of the three Working Group contributions to the AR6 was held on 1 - 5 May 2017 in Addis Ababa, Ethiopia. The draft outlines will be considered by the Panel when it meets in September 2017.














45th Session of IPCC, Guadalajara, Mexico


The 45th Session of the IPCC was held in the hotel Fiesta Americana, in the city of Guadalajara, Jalisco, United Mexican States, from 28 to 31 March 2017, preceded by the 53rd Session of the IPCC Bureau. The Panel has agreed the outlines of two Special Reports (Special Report on Climate Change and Oceans and the Cryosphere - Special Report on Climate Change and Land)














SR1.5 First Lead Author Meeting, Sao José dos Campos, Brazil


The First Lead Author Meeting for the Special Report on Global Warming on 1.5°C was hosted by the National Institute for Space Research (INPE) from 6 to 10 March 2017, in Sao José dos Campos, Brazil with the very kind support of the Brazilian government, through the Ministry of Foreign Affairs, and the National Institute for Space Research (INPE).














Women-ACS side event during COP22 in Marrakech, Morocco


Technical Support Unit of WGI and Association Marocaine des Sciences Regionales organized the side event "Women Advancing Climate and Climate Change Sciences" on November 14. Women-ACS is a new international initiative that aims to increase women's participation and accomplishments in the domain of climate and climate change sciences.














WGI co-organizes side event at COP22, Marrakech, Morocco, on urgent questions in climate research


On the opening day of COP22, IPCC Working Group I, the International Council for Science in partnership with the Scientific Committee on Antarctic Research (SCAR), the Inter-American Institute for Global Change Research (IAI) and the World Climate Research Programme (WCRP) convened a side event on key pressing issues in fundamental climate research following the Paris Agreement. Read more.



Speakers at the COP22 side event


Photo by IISD












44th Session of IPCC, Bangkok, Thailand


The 44 Session of the IPCC was held in the United Nations Convention Centre (UNCC) in Bangok, Thailand from 17 to 20 October 2016. The Intergovernmental Panel on Climate Change (IPCC) has agreed the outlines of two new reports that will help governments implement the Paris Climate Change Agreement. Download the press release



Some of the WGI Bureau and TSU members in Bangkok













SR1.5 Scoping meeting, Geneva, Switzerland


A scoping meeting for the Special Report on 1.5°C was held on 15-18 August 2016 in Geneva Switzerland. The meeting resulted in a draft Scoping Paper describing the objectives and an annotated outline of the Special Report as well as the process and timeline for its preparation to be considered by the 44th Session of the IPCC in October 2016. All the details on the scoping meeting of the Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways are available here and in the Scoping meeting report



SR1.5 Scoping Meeting particiapnts












43rd Session of IPCC, Nairobi, Kenya


The 43rd Session of the IPCC was held in the United Nations Office at Nairobi (UNON) in Gigiri from 11 to 13 April 2016. The Intergovernmental Panel on Climate Change (IPCC) has decided the strategy and timeline for its next series of reports, the Sixth Assessment Report (AR6), and the special reports that will be prepared in the next few years. Download the press release



Some of the WGI Bureau and TSU members


Photo by IISD/Kiara Worth












WGI Technical Support Unit implemented


WGI is glad to report on the implementation of our Technical Support Unit, acknowledging support from the French governement through the Ministery of Environment, Energy and Sea; the Ministery of Foreign Affairs; and the Ministery of Research and Education and thank the French focal point for his support to prepare and implement our TSU. The TSU is hosted at the Paris Saclay University, in close partnership with the Institut Pierre Simon Laplace research center. TSU information here.









Election of WGI Co-Chairs and Bureau


At the 42nd Session of the IPCC in Dubrovnik, Croatia, 5-8 October 2015, the Fifth Assessment Report period officially came to an end and a new bureau was elected for the Sixth Assessment Report.



The new Working Group I Co-Chairs



Panmao Zhai (China) and Valérie Masson-Delmotte (France)



The Co-Chairs will be supported by the newly elected Working Group I Vice Chairs:


Edvin Aldrian (Indonesia)

Fatima Driouech (Morocco)

Gregory Flato (Canada)

Jan Fuglestvedt (Norway)

Muhammad Tariq (Pakistan)

Carolina Vera (Argentina)

Noureddine Yassaa (Algeria)



The outgoing Co-Chairs of WGI, Thomas Stocker and Qin Dahe, as well as the WGI TSU for AR5, wish the new Co-Chairs and the WGI Bureau all the best and plenty of success for their important contributions to the Sixth Assessment cycle.