The Intergovernmental Panel on Climate Change (IPCC) was established in 1988 by the United Nations Environment Programme (UNEP) and the World Meteorological Organization (WMO). Scientists all over the world compile the current state of climate change for the panel. The IPCC provides the foundations for science-based decisions for policy makers without making political recommendations for action. The IPCC itself does not conduct any scientific research work. Scientists all over the world assess the current state of climate change research based on reviewed publications. Detailed rules of procedure, a multi-tiered review process and the inclusion of experts from around the globe ensure that the reports are balanced, reliable and complete. Government representatives of currently 195 parties to UNEP or WMO are given the opportunity to comment on the drafts of IPCC reports before publication and formally agree to the reports.
Products and organisation of the IPCC
Since its establishment, the IPCC has already published five comprehensive assessment reports. These lay out the latest findings in climate research, point out the risks and consequences of climate change and highlight options for mitigation and adaptation strategies. After the IPCC concluded its Fifth Assessment Report in 2013 and 2014, and the new IPCC bureau was elected in October 2015, work began on the Sixth Assessment Report, to be published in 2021 and 2022.
The IPCC also published more than ten special reports. Special reports are drawn up following the same procedure as assessment reports, but they deal with special topics. In addition, the IPCC draws up methodological guidelines and software for greenhouse gas inventories and offers emission factors for the calculation of greenhouse gas emissions. The IPCC data centre provides information on climate change and environmental and socio-economic data that are relevant for the assessment reports.
There are three working groups in the IPCC, each of which produces one part of the assessment reports. Working group I deals with the physical science basis of climate change. Working group II assesses the climate change vulnerability of socio-economic and natural systems and describes options for human adaptation to global warming. Working group III focusses on strategies for mitigation of climate change. In addition, IPCC task forces are established to tackle selected topics, usually within a specific time frame. For example, one task force is devoted to methods for calculating greenhouse gas emissions for national inventories. The working groups and the task forces work on the basis of mandates adopted by the plenary session.
Government representatives from the parties convene regularly for plenary sessions. At these sessions, the plenary determines topics for future assessment reports, adopts summaries of the respective assessment reports for political decision makers and consults on rules of procedure, for example, for drawing up reports. The plenary session also elects the IPCC bureau.
In October 2015, Hoesung Lee of South Korea was elected as the new chair of the IPCC. German biologist and climate researcher Hans-Otto Pörtner of the Alfred Wegener Institute was elected as co-chair of working group II. Both terms of office cover the period of drawing up the Sixth IPCC Assessment Report up to 2022.
The IPCC, its executive committee and bureau are supported in their work by the Secretariat in Geneva and the national IPCC focal points – Germany's is the Federal Environment Ministry. The German IPCC Coordination Office, run jointly by the Federal Environment Ministry and the Federal Ministry of Education and Research, supports the IPCC focal point in its work.
Products of the sixth IPCC assessment cycle (2016-22)
In 2021/22 the main product of the IPCC, the Sixth Assessment Report (AR&) will be published. The AR6 will consist of three parts, which are the responsibility of the respective IPCC working group, and a synthesis report.
Three special reports and a refinement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories have already been published. The special reports focus on land use, oceans/cryosphere and 1.5 degree Celsius global warming.
- Special Report Global Warming of 1.5 degree Celsius (SR1.5), October 2018
This special report summarises the scientific state of knowledge on the consequences of a global warming of 1.5 degree Celsius and the emission pathways consistent with such a warming. It also studies concrete measures for strengthening and accelerating the fight against climate change. A special chapter deals with the interactions with the Sustainable Development Goals (SDGs). The report was drawn up at the request of the United Nations Framework Convention on Climate Change (UNFCCC) in the context of the Paris Agreement.
- Special Report Climate Change and Land (SRCCL), August 2019
The Special Report Climate Change and Land addresses the interactions between climate change, desertification, land degradation, sustainable land management, food security and greenhouse gas fluxes in terrestrial ecosystems. It also assess the scientific knowledge on risk management and decision-making with a view to sustainable land management and sustainable development.
- Special Report on the Ocean and Cryosphere in a Changing Climate (SROCC), September 2019
The Special Report on the Ocean and Cryosphere in a Changing Climate deals with high mountain and polar regions, sea level rise, changes in the world’s oceans and extreme and abrupt shifts. It also addresses the consequences and risks for low-lying islands, coastal regions and communities, marine ecosystems and communities that depend on them as well as risk management and adaptation.
Products of the fifth IPCC assessment cycle
In 2013/2014, the IPCC adopted its Fifth Assessment Report (AR5). The synthesis report contains the reports drawn up by the three IPCC working groups, summarises the results and puts them in an overarching context. The AR5 substantiates human influence on the climate system and therefore confirms the reality of an anthropogenic climate change. It also describes the associated risks and consequences as well as strategies for adaptation and mitigation.
The first volume of this report, on the physical science basis of climate change, was published in Stockholm in September 2013. Volumes II and III were adopted in Yokohama in March 2014 and in Berlin in April 2014 respectively. The session in Berlin was presided over by German economist Ottmar Edenhofer of the Potsdam Institute for Climate Impact Research (PIK), co-chair of IPCC Working Group III during the assessment cycle for the Fifth Assessment Report. The synthesis report was published in Copenhagen in October 2014.
The IPCC also presented two special reports during the fifth assessment cycle, one on the topic of climate change and extreme events in November 2011 (SREX), and one on renewable energy sources in May 2011 (SRREN).
The preparation of reports must follow certain procedures. At the outset, the plenary session makes the decision to prepare a report and determines the scope for the working groups. Authors are then selected for the three working groups. The governments of the 195 member countries and around 100 accredited observer organisations may suggest suitable authors. The working group bureaus select the authors from the list of nominees.
These teams are composed of many experts – the co-chairs of the working groups, coordinating lead authors and lead authors, contributing authors and reviewers for the respective chapters. Some 830 authors were involved in preparing the Fifth Assessment Report, including 40 experts from German universities, research institutes and the private sector. The composition of the groups of authors ensures that they represent a variety of points of view, in addition to pertinent expertise.
In addition to this, different world regions and both genders must be represented in each team to ensure that author teams are balanced. To compile a report, authors mainly draw from articles published in peer-reviewed journals. Authors have to agree on a way to present and scientifically assess the facts. Disparate views, knowledge gaps and uncertainties are explicitly mentioned in the report. The first drafts prepared by the working groups are reviewed several times by experts and government representatives and revised in the process.
Governments adopt the summary for policymakers of a IPCC report in a plenary meeting line by line. The plenary takes particular care that the statements are complete, understandable and balanced. The authors decide whether the phrasing suggested by the governments is correct. Through the adoption of the IPCC reports, the governments recognise the scientific results of the assessment reports. The reports will then be published and presented.