The Intergovernmental Panel on Climate Change (IPCC) is an
intergovernmental body
An international organization or international organisation (see spelling differences), also known as an intergovernmental organization or an international institution, is a stable set of norms and rules meant to govern the behavior of states an ...
of the
United Nations
The United Nations (UN) is an intergovernmental organization whose stated purposes are to maintain international peace and international security, security, develop friendly relations among nations, achieve international cooperation, and be ...
. Its job is to advance scientific knowledge about
climate change
In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to E ...
caused by human activities. The
World Meteorological Organization
The World Meteorological Organization (WMO) is a specialized agency of the United Nations responsible for promoting international cooperation on atmospheric science, climatology, hydrology and geophysics.
The WMO originated from the Internati ...
(WMO) and the
United Nations Environment Programme
The United Nations Environment Programme (UNEP) is responsible for coordinating responses to environmental issues within the United Nations system. It was established by Maurice Strong, its first director, after the United Nations Conference on th ...
(UNEP) established the IPCC in 1988. The
United Nations
The United Nations (UN) is an intergovernmental organization whose stated purposes are to maintain international peace and international security, security, develop friendly relations among nations, achieve international cooperation, and be ...
endorsed the creation of the IPCC later that year.
It has a secretariat in
Geneva
Geneva ( ; french: Genève ) frp, Genèva ; german: link=no, Genf ; it, Ginevra ; rm, Genevra is the List of cities in Switzerland, second-most populous city in Switzerland (after Zürich) and the most populous city of Romandy, the French-speaki ...
, Switzerland, hosted by the WMO. It has 195
member states who govern the IPCC. The member states elect a bureau of scientists to serve through an assessment cycle. A cycle is usually six to seven years. The bureau selects experts to prepare IPCC reports.
It draws the experts from nominations by governments and observer organisations. The IPCC has three working groups and a task force, which carry out its scientific work.
The IPCC informs governments about the state of knowledge of climate change. It does this by examining all the relevant scientific literature on the subject. This includes the natural,
economic
An economy is an area of the production, distribution and trade, as well as consumption of goods and services. In general, it is defined as a social domain that emphasize the practices, discourses, and material expressions associated with the ...
and social impacts and
risks
In simple terms, risk is the possibility of something bad happening. Risk involves uncertainty about the effects/implications of an activity with respect to something that humans value (such as health, well-being, wealth, property or the environme ...
. It also covers possible
response options. The IPCC does not conduct its own original research. It aims to be objective and comprehensive. Thousands of scientists and other experts volunteer to
review
A review is an evaluation of a publication, product, service, or company or a critical take on current affairs in literature, politics or culture. In addition to a critical evaluation, the review's author may assign the work a rating to indi ...
the publications. They compile key findings into "Assessment Reports" for policymakers and the general public;
Experts have described this work as the biggest
peer review
Peer review is the evaluation of work by one or more people with similar competencies as the producers of the work (peers). It functions as a form of self-regulation by qualified members of a profession within the relevant field. Peer review ...
process in the scientific community.
The IPCC is an internationally accepted authority on climate change. Leading climate scientists and all member governments endorse its findings.
Media, governments, civil society organisations and businesses cite its reports. IPCC reports play a key role in the annual climate negotiations held by the
United Nations Framework Convention on Climate Change
The United Nations Framework Convention on Climate Change (UNFCCC) established an international environmental treaty to combat "dangerous human interference with the climate system", in part by stabilizing greenhouse gas concentrations in th ...
(UNFCCC).
[IPCC. . Approved 1–3 October 1998, last amended 14–18 October 2013.] The IPCC
Fifth Assessment Report
The Fifth Assessment Report (AR5) of the United Nations Intergovernmental Panel on Climate Change (IPCC) is the fifth in a series of such reports and was completed in 2014.IPCC (2014The IPCC’s Fifth Assessment Report (AR5) leaflet/ref> As ha ...
was an important influence on the landmark
Paris Agreement
The Paris Agreement (french: Accord de Paris), often referred to as the Paris Accords or the Paris Climate Accords, is an international treaty on climate change. Adopted in 2015, the agreement covers climate change mitigation, Climate change a ...
in 2015.
The IPCC shared the
2007 Nobel Peace Prize with
Al Gore
Albert Arnold Gore Jr. (born March 31, 1948) is an American politician, businessman, and environmentalist who served as the 45th vice president of the United States from 1993 to 2001 under President Bill Clinton. Gore was the Democratic Part ...
for contributions to the understanding of climate change.
In 2015 the IPCC began its sixth assessment cycle. It will complete it in 2023. In August 2021, the IPCC published its Working Group I contribution to the
Sixth Assessment Report
The Sixth Assessment Report (AR6) of the United Nations (UN) Intergovernmental Panel on Climate Change (IPCC) is the sixth in a series of reports which assess scientific, technical, and socio-economic information concerning climate change. Thre ...
(IPCC AR6) on the physical science basis of climate change.
[IPCC, 2021: ]
Climate Change 2021: The Physical Science Basis
Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change''[Masson-Delmotte, V., P. Zhai, A. Pirani, S.L. Connors, C. Péan, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M.I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J.B.R. Matthews, T.K. Maycock, T. Waterfield, O. Yelekçi, R. Yu, and B. Zhou (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, In press, doi:10.1017/9781009157896. ''The Guardian'' described this report as the "starkest warning yet" of "major inevitable and irreversible climate changes".
Many newspapers around the world echoed this theme.
In February 2022, the IPCC released its Working Group II report on impacts and adaptation. It published Working Group III's "mitigation of climate change" contribution to the Sixth Assessment in April 2022. The Sixth Assessment Report is due to conclude with a Synthesis Report in March 2023.
During this period of the Sixth Assessment Report, the IPCC has released three special reports. The first and most influential was the
Special Report on Global Warming of 1.5°C in 2018. In 2019 the
Special Report on Climate Change and Land (SRCCL), and the
(SROCC) came out. The IPCC also updated its methodologies in 2019. So the sixth assessment cycle is the most ambitious in the IPCC's history.
Origins
The predecessor of the IPCC was the
Advisory Group on Greenhouse Gases The Advisory Group on Greenhouse Gases, created in 1986, was an advisory body for the review of studies into the greenhouse effect. The group was created by the International Council of Scientific Unions, the United Nations Environment Programme, a ...
(AGGG). Three organizations set up the AGGG in 1986. These were the
International Council of Scientific Unions
The International Council for Science (ICSU, after its former name, International Council of Scientific Unions) was an international non-governmental organization devoted to international cooperation in the advancement of science. Its members ...
, the
United Nations Environment Programme
The United Nations Environment Programme (UNEP) is responsible for coordinating responses to environmental issues within the United Nations system. It was established by Maurice Strong, its first director, after the United Nations Conference on th ...
(UNEP), and the
World Meteorological Organization
The World Meteorological Organization (WMO) is a specialized agency of the United Nations responsible for promoting international cooperation on atmospheric science, climatology, hydrology and geophysics.
The WMO originated from the Internati ...
(WMO). The AGGG reviewed scientific research on greenhouse gases. It also studied increases in greenhouse gases.
Climate science
Climatology (from Greek , ''klima'', "place, zone"; and , '' -logia'') or climate science is the scientific study of Earth's climate, typically defined as weather conditions averaged over a period of at least 30 years. This modern field of stu ...
was becoming more complicated and covering more disciplines. This small group of scientists lacked the resources to cover climate science.
The
United States Environmental Protection Agency
The Environmental Protection Agency (EPA) is an independent executive agency of the United States federal government tasked with environmental protection matters. President Richard Nixon proposed the establishment of EPA on July 9, 1970; it be ...
sought an international convention to restrict
greenhouse gas emissions
Greenhouse gas emissions from human activities strengthen the greenhouse effect, contributing to climate change. Most is carbon dioxide from burning fossil fuels: coal, oil, and natural gas. The largest emitters include coal in China and ...
. The
Reagan Administration
Ronald Reagan's tenure as the 40th president of the United States began with his first inauguration on January 20, 1981, and ended on January 20, 1989. Reagan, a Republican from California, took office following a landslide victory over ...
worried that independent scientists would have too much influence. The WMO and UNEP therefore created the IPCC as an intergovernmental body in 1988. Scientists take part in the IPCC as both experts and government representatives. The IPCC produces reports backed by all leading relevant scientists. Member governments must also endorse the reports by consensus agreement. So the IPCC is both a scientific body and an organization of governments. Its job is to tell governments what scientists know about climate change. It also examines the
impacts of climate change
The effects of climate change impact the physical environment, ecosystems and human societies. The environmental effects of climate change are broad and far-reaching. They affect the water cycle, oceans, sea and land ice (glaciers), sea leve ...
and options for dealing with it. The IPCC does this by assessing peer-reviewed scientific literature.
The
United Nations
The United Nations (UN) is an intergovernmental organization whose stated purposes are to maintain international peace and international security, security, develop friendly relations among nations, achieve international cooperation, and be ...
endorsed the creation of the IPCC in 1988. The
General Assembly resolution
A United Nations General Assembly resolution is a decision or declaration voted on by all member states of the United Nations in the General Assembly.
General Assembly resolutions usually require a simple majority (50 percent of all votes plus on ...
noted that human activity could change the climate. This could lead to severe economic and social consequences. It said increasing concentrations of greenhouse gases could
warm the planet. This would cause the
sea level to rise. The effects for humanity would be disastrous if timely steps were not taken.
Organization
![IPCC adoption of the Summary for Policymakers of the Special Report on Global Warming of 1](https://upload.wikimedia.org/wikipedia/commons/f/fc/IPCC_adoption_of_the_Summary_for_Policymakers_of_the_Special_Report_on_Global_Warming_of_1.5%C2%B0C.jpg)
Way of working
The IPCC does not conduct original research. It produces comprehensive assessments on the state of knowledge of climate change. It prepares reports on special topics relevant to climate change. It also produces methodologies. These methodologies help countries estimate their greenhouse gas emissions and removals through sinks. Its assessments build on previous reports and scientific publications. Over the course of six assessments the reports reflect the growing evidence for a changing climate. And they show how this is due to human activity.
Rules and governing principles
The IPCC has adopted its rules of procedure in the "Principles Governing IPCC Work". These state that the IPCC will assess:
* the risk of
climate change
In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to E ...
caused by human activities,
* its
potential impacts, and
* possible
options for prevention.
Under IPCC rules its assessments are comprehensive, objective, open and transparent. They cover all the information relevant to the scientific understanding of climate change. This draws on scientific, technical and socioeconomic information. IPCC reports must be neutral regarding policy recommendations. However, they may address the objective factors relevant to enacting policies.
Structure
The IPCC has the following structure:
* IPCC Panel: Meets in
plenary session
A plenary session or plenum is a session of a conference which all members of all parties are to attend. Such a session may include a broad range of content, from keynotes to panel discussions, and is not necessarily related to a specific st ...
about twice a year. It may meet more often for the approval of reports.
It controls the IPCC's structure, procedures, work program and budget. It accepts and approves IPCC reports. The Panel is the IPCC corporate entity.
* Chair: Elected by the Panel. Chairs the Bureau and other bodies. Represents the organization.
* Bureau: Elected by the Panel. It currently has 34 members from different geographic regions. Besides the Chair and three IPCC Vice-Chairs, they provide the leadership for the IPCC's three Working Groups and Task Force.
It provides guidance to the Panel on the scientific and technical aspects of its work.
* Working Groups: Each has two Co-Chairs, one from a developed and one from a developing country. A technical support unit supports each Working Group. Working Group sessions approve the Summary for Policymakers of assessment and special reports. Each Working Group has a Bureau. This consists of its Co-Chairs and Vice-Chairs, who are also members of the IPCC Bureau.
** Working Group I: Assesses scientific aspects of the climate system and climate change. Co-Chairs:
Valérie Masson-Delmotte
Valerie Masson-Delmotte is a French climate scientist and Research Director at the French Alternative Energies and Atomic Energy Commission, where she works in the Climate and Environment Sciences Laboratory (LSCE). She uses data from past clim ...
and
Panmao Zhai
** Working Group II: Assesses the impacts of climate change on human and natural systems. Assesses adaptation options. Co-Chairs: Hans-Otto Pörtner and
Debra Roberts
Debra C. Roberts is a South African government worker and one of the six co-chairs of the Intergovernmental Panel on Climate Change. She was elected co-chair of Working Group II for the sixth assessment in 2015.
She is head of the Sustainable a ...
** Working Group III: Assesses how to stop climate change by limiting greenhouse gas emissions. (Known as "mitigation".) Co-Chairs: Priyadarshi R. Shukla and
Jim Skea
* Task Force on National Greenhouse Gas Inventories.
Develops methodologies for estimating greenhouse gas emissions. Co-Chairs: Kiyoto Tanabe and Eduardo Calvo Buendía
** Task Force Bureau: Comprises the two Co-Chairs, who are also members of the IPCC Bureau, and 12 members.
* Executive Committee: Comprises the Chair, IPCC Vice-Chairs and the Co-Chairs of the Working Groups and Task Force. It addresses urgent issues that arise between sessions of the Panel.
* Secretariat: Administers activities, supports the Chair and Bureau, point of contact for governments. Supported by UNEP and the WMO.
Chair
The chair of the IPCC is Korean economist
Hoesung Lee
Hoesung Lee (born December 31, 1945) is a South Korean economist and current chair of the Intergovernmental Panel on Climate Change. He is professor in the economics of climate change, energy and sustainable development in thGraduate School of ...
. Lee has served since 8 October 2015 with the election of the new IPCC Bureau. His predecessor
Rajendra K. Pachauri
Rajendra Kumar Pachauri (20 August 1940 – 13 February 2020) was the chairman of the Intergovernmental Panel on Climate Change (IPCC) from 2002 to 2015, during the fourth and fifth assessment cycles. Under his leadership the IPCC was awarded ...
, elected in 2002, resigned in February 2015. Vice-Chair
Ismail El Gizouli
Ismail Abdel Rahim El Gizouli is a Sudanese civil servant specializing in energy and environment and a member of the bureau of the Intergovernmental Panel on Climate Change (IPCC). He has acted as interim chairman of the IPCC since 24 February 2015 ...
served as acting chair until the election of the new Bureau. The previous chairs were
Robert Watson, elected in 1997, and
Bert Bolin, elected in 1988.
Panel
The Panel consists of representatives appointed by governments. They take part in plenary sessions of the IPCC and its Working Groups. Non-governmental and intergovernmental organizations may attend as observers. Meetings of IPCC bodies are by invitation only.
About 500 people from 130 countries attended the 48th Session of the Panel in Incheon, Republic of Korea. This took place in October 2018. They included 290 government officials and 60 representatives of observer organizations. The opening ceremonies of sessions of the Panel and of Lead Author Meetings are open to media. Otherwise IPCC meetings are closed.
Funding
The IPCC receives funding through a dedicated
trust fund
A trust is a legal relationship in which the holder of a right gives it to another person or entity who must keep and use it solely for another's benefit. In the Anglo-American common law, the party who entrusts the right is known as the " sett ...
. UNEP and the WMO established the fund in 1989. The trust fund receives annual financial contributions from member governments. The WMO, UNEP and other organizations also contribute. Payments are voluntary and there is no set amount required. The WMO covers the operating costs of the secretariat. It also sets the IPCC's financial regulations and rules. The Panel sets the annual budget.
List of all reports
Activities other than report preparation
The IPCC bases its work on the decisions of the WMO and UNEP, which established the IPCC. It also supports the work of the UNFCCC.
The main work of the IPCC is to prepare assessment and other reports. It also supports other activities such as the Data Distribution Centre. This helps manage data related to IPCC reports.
The IPCC has a "Gender Policy and Implementation Plan" to pay attention to gender in its work. It aims to carry out its work in an inclusive and respectful manner. The IPCC aims for balance in participation in IPCC work. This should offer all participants equal opportunity.
Communications and dissemination activities
The IPCC enhanced its communications activities for the Fifth Assessment Report. For instance it made the approved report and press release available to registered media under embargo before the release. And it expanded its outreach activities with an outreach calendar. The IPCC held an Expert Meeting on Communication in February 2016, at the start of the Sixth Assessment Report cycle. Members of the old and new Bureaus worked with communications experts and practitioners at this meeting. This meeting produced a series of recommendations. The IPCC adopted many of them. One was to bring people with communications expertise into the Working Group Technical Support Units. Another was to consider communications questions early on in the preparation of reports.
Following these steps in communications, the IPCC saw a significant increase in media coverage of its reports. This was particularly the case with the ''
Special Report on Global Warming of 1.5 °C
The Special Report on Global Warming of 1.5°C (SR15) was published by the Intergovernmental Panel on Climate Change (IPCC) on 8 October 2018. The report, approved in Incheon, South Korea, includes over 6,000 scientific references, and was prep ...
'' in 2018 and ''Climate Change 2021: The Physical Science Basis'', the Working Group I contribution to the
Sixth Assessment Report
The Sixth Assessment Report (AR6) of the United Nations (UN) Intergovernmental Panel on Climate Change (IPCC) is the sixth in a series of reports which assess scientific, technical, and socio-economic information concerning climate change. Thre ...
, in 2021. There was also much greater public interest, reflected in the youth and other movements that emerged in 2018.
IPCC reports are important for
public awareness of climate change
file:20210126 Peoples' Climate Vote - Public belief in climate emergency - United Nations Development Programme.svg, upright=1.3, ''Perception of seriousness:'' Results of a survey overseen by the United Nations Development Programme on belief ...
and related policymaking. This has led to a number of academic studies of IPCC communications, for example in 2021.
Archiving
The IPCC archives its reports and electronic files on its website. They include the review comments on drafts of reports. The Environmental Science and Public Policy Archives in the
Harvard Library also archives them..
Assessment reports
Between 1990 and 2022, the IPCC has published six comprehensive assessment reports reviewing the latest climate science. The IPCC has also produced 14 special reports on particular topics.
Each assessment report has four parts. These are a contribution from each of the three working groups, plus a synthesis report. The synthesis report integrates the working group contributions. It also integrates any special reports produced in that assessment cycle.
Review process of scientific literature
The IPCC does not carry out its own research. It does not monitor climate-related data. The reports by IPCC assess scientific papers and independent results from other scientific bodies. The IPCC sets a deadline for publication of scientific papers that a report will cover. That report will not include new information that emerges after this deadline. However, there is a steady evolution of key findings and levels of
scientific confidence from one assessment report to the next. Each IPCC report notes areas where the science has improved since the previous report. It also notes areas that would benefit from further research.
Selection and role of authors
The IPCC Bureau or Working Group Bureau selects the authors of the reports from government nominations. Lead authors of IPCC reports assess the available information about climate change based on published sources.
[
] According to IPCC guidelines, authors should give priority to
peer-reviewed sources.
Authors may refer to non-peer-reviewed sources ("grey literature"), if they are of sufficient quality.
These could include reports from government agencies and non-governmental organizations. Industry journals and
model results are other examples of non-peer-reviewed sources.
Authors prepare drafts of a full report divided into chapters. They also prepare a technical summary of the report, and a
summary for policymakers.
Each chapter has a number of authors to write and edit the material. A typical chapter has two coordinating lead authors, ten to fifteen lead authors and a larger number of contributing authors. The coordinating lead authors assemble the contributions of the other authors. They ensure that contributions meet stylistic and formatting requirements. They report to the Working Group co-chairs. Lead authors write sections of chapters. They invite contributing authors to prepare text, graphs or data for inclusion.
The Bureau aims for a range of views, expertise and geographical representation in its choice of authors. This ensures the author team includes experts from both developing and developed countries. The Bureau also seeks a balance between male and female authors. And it aims for a balance between those who have worked previously on IPCC reports and those new to the process.
Scientists who work as authors on IPCC reports do not receive any compensation for this work. They depend on the salaries they receive from their home institutions or other work. The work is labour-intensive with a big time commitment. It can disrupt participating scientists' research. This has led to concern that the IPCC process may discourage qualified scientists from participating.
Review process for assessment reports
Expert reviewers comment at different stages on the drafts. Reviewers come from member governments and IPCC observers. Also, anyone may become an IPCC reviewer by stating they have the relevant expertise.
There are generally three stages in the review process.
First comes expert review of the first draft of the chapters. The next stage is a review by governments and experts of the revised draft of the chapters and the first draft of the Summary for Policymakers. The third stage is a government review of the revised Summary for Policymakers. Review comments and author responses remain in an open archive for at least five years. Finally government representatives together with the authors review the Summary for Policymakers. They go through the Summary for Policymakers line by line to ensure it is a good summary for the underlying report. This final review of the Summary of Policymakers takes place at sessions of the responsible working group or of the Panel.
There are several types of endorsement which documents receive:
* Approval - Material has been subject to detailed, line by line discussion and agreement. (The relevant Working Groups ''approve'' Working Group Summaries for Policymakers. The Panel ''approves'' the Synthesis Report Summary for Policymakers.)
* Adoption - Endorsed section by section (not line by line). (The Panel ''adopts'' the full IPCC Synthesis Report. It also ''adopts'' Overview Chapters of Methodology Reports.)
* Acceptance - Not been subject to line by line discussion and agreement. But it presents a comprehensive, objective and balanced view of the subject matter. (Working Groups ''accept'' their reports. The Panel ''accepts'' Working Group Summaries for Policymakers after working group approval. The Panel ''accepts'' Methodology Reports.)
Key findings and impacts
Assessment reports one to five (1990 to 2014)
![John Houghton High Wycombe 20050226](https://upload.wikimedia.org/wikipedia/commons/8/81/John_Houghton_High_Wycombe_20050226.jpg)
* The IPCC’s
First Assessment Report (FAR) appeared in 1990. The report gave a broad overview of climate change science. It discussed uncertainties and provided evidence of warming. The authors said they are certain that greenhouse gases are increasing in the atmosphere because of human activity. This is resulting in more warming of the
Earth
Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surfa ...
's surface. The report led to the establishment of the
United Nations Framework Convention on Climate Change
The United Nations Framework Convention on Climate Change (UNFCCC) established an international environmental treaty to combat "dangerous human interference with the climate system", in part by stabilizing greenhouse gas concentrations in th ...
(UNFCCC).
* The
Second Assessment Report (SAR), was published in 1995. It strengthened the findings of the First Assessment Report. The evidence suggests that there is a discernible human influence on the global climate, it said. The Second Assessment Report provided important material for the negotiations leading to the UNFCCC’s
Kyoto Protocol.
* The
Third Assessment Report
The IPCC Third Assessment Report (TAR), ''Climate Change 2001'', is an assessment of available scientific and socio-economic information on climate change by the IPCC. Statements of the IPCC or information from the TAR are often used as a referenc ...
(TAR) was completed in 2001. It found more evidence that most of the global warming seen over the previous 50 years was due to human activity. The report includes a graph reconstructing global temperature since the year 1000. The sharp rise in temperature in recent years gave it the name “
hockey stick
A hockey stick is a piece of sports equipment used by the players in all the forms of hockey to move the ball or puck (as appropriate to the type of hockey) either to push, pull, hit, strike, flick, steer, launch or stop the ball/ puck during pla ...
”. This became a powerful image of how temperature is soaring with climate change. The report also shows how adaptation to the effects of climate change can reduce some of its ill effects.
* The IPCC’s
Fourth Assessment Report (AR4) was published in 2007. It gives much greater certainty about climate change. It states: “Warming of the climate system is unequivocal..." The report helped make people around the world aware of climate change. The IPCC shared the
Nobel Peace Prize
The Nobel Peace Prize is one of the five Nobel Prizes established by the will of Swedish industrialist, inventor and armaments (military weapons and equipment) manufacturer Alfred Nobel, along with the prizes in Chemistry, Physics, Physiolog ...
in the year of the report’s publication for this work (see below).
* The
Fifth Assessment Report
The Fifth Assessment Report (AR5) of the United Nations Intergovernmental Panel on Climate Change (IPCC) is the fifth in a series of such reports and was completed in 2014.IPCC (2014The IPCC’s Fifth Assessment Report (AR5) leaflet/ref> As ha ...
(AR5) was published in 2013 and 2014. This report again stated the fact of climate change. It warned of the dangerous risks. And it emphasized how the world can counter climate change. Three key findings were for example: Firstly, human influence on the
climate system
Earth's climate system is a complex system having five interacting components: the atmosphere (air), the hydrosphere (water), the cryosphere (ice and permafrost), the lithosphere (earth's upper rocky layer) and the biosphere (living things). '' ...
is clear. Secondly, the more we disrupt our climate, the more we risk severe, pervasive and irreversible
impacts. And thirdly, we have the means to limit climate change and build a more prosperous,
sustainable future. The report's findings were the scientific foundation of the UNFCCC’s 2015
Paris Agreement
The Paris Agreement (french: Accord de Paris), often referred to as the Paris Accords or the Paris Climate Accords, is an international treaty on climate change. Adopted in 2015, the agreement covers climate change mitigation, Climate change a ...
.
Sixth assessment report (2021/2022)
The IPCC's most recent report is the
Sixth Assessment Report (AR6). The first three instalments of AR6 appeared in 2021 and 2022. Its final synthesis report is due in March 2023.
The IPCC published the Working Group I report, ''Climate Change 2021: The Physical Science Basis'', in August 2021.
It confirms that the climate is already changing in every region. Many of these changes have not been seen in thousands of years. Many of them such as
sea-level rise
Globally, sea levels are rising due to human-caused climate change. Between 1901 and 2018, the globally averaged sea level rose by , or 1–2 mm per year on average.IPCC, 2019Summary for Policymakers InIPCC Special Report on the Ocean and Cryo ...
are irreversible over hundreds of thousands of years. Strong reductions in greenhouse gas emissions would limit climate change. But it could take 20-30 years for the climate to stabilize. This report attracted enormous media and public attention. U.N. Secretary-General
António Guterres described it as “code red for humanity”.
The IPCC published the Working Group II report, ''Climate Change 2022: Impacts, Adaptation and Vulnerability'', in February 2022. Climate change due to human activities is already affecting the lives of billions of people, it said. It is disrupting nature. The world faces unavoidable hazards over the next two decades even with global warming of 1.5ºC, it said.
The IPCC published the Working Group III report, ''Climate Change 2022: Mitigation of Climate Change'', in April 2022. It will be impossible to limit warming to 1.5ºC without immediate and deep cuts in greenhouse gas emissions. It is still possible to halve emissions by 2050, it said.
Other reports
Special reports
The IPCC also publishes other types of reports. It produces Special Reports on topics proposed by governments or observer organizations. Between 1994 and 2019 the IPCC published 14 special reports. Now usually more than one working group cooperates to produce a special report. The preparation and approval process is the same as for assessment reports.
Special reports in 2011
During the fifth assessment cycle the IPCC produced two special reports. It completed the Special Report on Renewable Energy Sources and Climate Change Mitigation (SRREN) in 2011. Working Group III prepared this report. The report examined options to use different types of renewable energy to replace fossil fuels. The report noted that the cost of most renewables technologies had fallen. It was likely to fall even more with further advances in technology. It said renewables could increase access to energy. The report reviewed 164 scenarios that examine how renewables could help stop climate change. In more than half of these scenarios, renewables would contribute more than 27% of primary energy supply in mid-century. This would be more than double the 13% share in 2008. In the scenarios with the highest shares for renewable energy, it contributes 77% by 2050.
Later in 2011 the IPCC released the Special Report on Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation (SREX). This was a collaboration between Working Groups I and II. It was the first time two IPCC working groups worked together on a special report. The report shows how climate change has contributed to changes in extreme weather. And it show how policies to avoid and prepare for extreme weather events can reduce their impact. In the same way policies to respond to events and recover from them can make societies more resilient.
Special reports 2018-2019
During the sixth assessment cycle the IPCC produced three special reports. This made it the most ambitious cycle in IPCC history. The
UNFCCC
The United Nations Framework Convention on Climate Change (UNFCCC) established an international environmental treaty to combat "dangerous human interference with the climate system", in part by stabilizing greenhouse gas concentrations in th ...
set a goal of keeping global warming well below 2ºC while trying to hold it at 1.5ºC, when it reached the
Paris Agreement
The Paris Agreement (french: Accord de Paris), often referred to as the Paris Accords or the Paris Climate Accords, is an international treaty on climate change. Adopted in 2015, the agreement covers climate change mitigation, Climate change a ...
at
COP21
The 2015 United Nations Climate Change Conference, COP 21 or CMP 11 was held in Paris, France, from 30 November to 12 December 2015. It was the 21st yearly session of the Conference of the Parties (COP) to the 1992 United Nations Framework Conve ...
in 2015. But at the time there was little understanding of what warming of 15ºC meant. There was little scientific research explaining how the impacts of 1.5ºC would differ from 2ºC. And there was little understanding about how to keep warming to 1.5ºC. So the UNFCCC invited the IPCC to prepare a report on global warming of 1.5ºC. All three IPCC working groups collaborated to produce the report. The IPCC released the
Special Report on Global Warming of 1.5 °C
The Special Report on Global Warming of 1.5°C (SR15) was published by the Intergovernmental Panel on Climate Change (IPCC) on 8 October 2018. The report, approved in Incheon, South Korea, includes over 6,000 scientific references, and was prep ...
(SR15) in 2018. The report showed that it was possible to keep warming below 1.5ºC during the 21st century. But this would mean deep cuts in emissions. It would also mean rapid, far-reaching changes in all aspects of society. The report showed warming of 2ºC would have much more severe impacts than 1.5ºC. In other words: every bit of warming matters. SR15 had an unprecedented impact for an IPCC report in the media and with the public.
It put the 1.5ºC target at the center of climate activism.
In 2019 the IPCC released two more special reports that examine different parts of the climate system. The
Special Report on Climate Change and Land (SRCCL) examined how the way we use land affects the climate. It looked at emissions from activities such as farming and forestry rather than from energy and transport. It also looked at how climate change is affecting land. All three IPCC working groups and its Task Force on National Greenhouse Gas Inventories collaborated on the report. The report found that climate change is adding to the pressures we are putting on our land we use to live on and grow our food. It will only be possible to keep warming well below 2ºC if we reduce emissions from all sectors including land and food, it said.
The
(SROCC) examined how the ocean and frozen parts of the planet interact with climate change. (The
cryosphere
]
The cryosphere (from the Ancient Greek, Greek ''kryos'', "cold", "frost" or "ice" and ''sphaira'', "globe, ball") is an all-encompassing term for those portions of Earth's surface where water is in solid form, including sea ice, lake ice, ri ...
includes frozen systems such as ice sheets, glaciers and permafrost.) IPCC Working Groups I and II prepared the report. The report highlighted the need to tackle unprecedented changes in the ocean and cryosphere. It also showed how
Climate change adaptation, adaptation could help
sustainable development
Sustainable development is an organizing principle for meeting human development goals while also sustaining the ability of natural systems to provide the natural resources and ecosystem services on which the economy and society depend. The des ...
.
Methodology Reports
The IPCC has a National Greenhouse Gas Inventories Programme. It develops methodologies and software for countries to report their
greenhouse gas emissions. The IPCC’s Task Force on National Greenhouse Gas Inventories (TFI) has managed the program since 1998.
Japan’s Institute for Global Environmental Strategies (IGES) hosts the TFI’s Technical Support Unit.
The IPCC approves its methodology reports at sessions of the Panel. The Panel adopts the Methodology Report’s Overview Chapter by endorsing it section by section.
Revised 1996 IPCC Guidelines
The IPCC released its first Methodology Report, the IPCC ''Guidelines for National Greenhouse Gas Inventories'', in 1994. The ''Revised 1996 IPCC Guidelines for National Greenhouse Gas Inventories'' updated this report. Two “good practice reports” complete these guidelines. These are the ''Good Practice Guidance'' ''and Uncertainty Management in National Greenhouse Gas Inventories'' and ''Good Practice Guidance for Land Use, Land-Use Change and Forestry''. Parties to the
UNFCCC
The United Nations Framework Convention on Climate Change (UNFCCC) established an international environmental treaty to combat "dangerous human interference with the climate system", in part by stabilizing greenhouse gas concentrations in th ...
and its
Kyoto Protocol use the 1996 guidelines and two good practice reports for their annual submissions of inventories.
2006 IPCC Guidelines
The ''2006 IPCC Guidelines for National Greenhouse Gas Inventories'' further update these methodologies. They include a large number of “default emission factors”. These are factors to estimate the amount of emissions for an activity. The IPCC prepared this new version of the guidelines at the request of the UNFCCC. The UNFCCC accepted them for use at its
2013 Climate Change Conference, COP19, in Warsaw. The IPCC added further material in its ''2019 Refinement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories''.
The TFI has started preparations for a methodology report on short-lived climate forcers (SLCFs). It will complete this report in the next assessment cycle, the seventh.
Challenges and controversies
IPCC reports also attract criticism. Criticisms come from both people who say the reports exaggerate the risks and people who say they understate them.
The IPCC consensus approach has faced internal and external challenges.
[Evaluation, characterization, and communication of uncertainty by the intergovernmental panel on climate change—an introductory essay. Climatic Change An Interdisciplinary, International Journal Devoted to the Description, Causes and Implications of Climatic Change, Gary Yohe and Michael Oppenheimer](_blank)
2011
Conservative nature of IPCC reports
Some critics have argued that IPCC reports tend to be
conservative
Conservatism is a cultural, social, and political philosophy that seeks to promote and to preserve traditional institutions, practices, and values. The central tenets of conservatism may vary in relation to the culture and civilization in ...
. They say the reports consistently underestimate the pace and impacts of global warming.
This leads to findings that are the "lowest common denominator", they say.
Stefan Rahmstorf
Stefan Rahmstorf (born 22 February 1960) is a German oceanographer and climatologist. Since 2000, he has been a Professor of Physics of the Oceans at Potsdam University. He studied physical oceanography at Bangor University and received his Ph. ...
, professor of physics and oceanography at Potsdam University, stated in 2007: "In a way, it is one of the strengths of the IPCC to be very conservative and cautious and not overstate any climate change risk". IPCC reports aim to inform policymakers about the state of knowledge on climate change. They do this by assessing the findings of the thousands of scientific papers available on the subject at a given time. Individual publications may have different conclusions to IPCC reports. This includes those appearing just after the release of an IPCC report. This can lead to criticism that the IPCC is either alarmist or conservative. New findings must wait for the next assessment for consideration.
Potential political influence
A memo by
ExxonMobil to the
Bush administration in the United States in 2002 was an example of possible political influence on the IPCC. The memo led to strong Bush administration lobbying to oust
Robert Watson, a climate scientist, as IPCC chair. They sought to replace him with
Rajendra Pachauri
Rajendra Kumar Pachauri (20 August 1940 – 13 February 2020) was the chairman of the Intergovernmental Panel on Climate Change (IPCC) from 2002 to 2015, during the fourth and fifth assessment cycles. Under his leadership the IPCC was awarded t ...
. Many considered Pachauri at the time as more mild-mannered and industry-friendly.
Governments form the membership of the IPCC. They are the prime audience for IPCC reports. IPCC rules give them a formal role in the scoping, preparation and approval of reports. For instance governments take part in the review process and work with authors to approve the Summary for Policymakers of reports. But some activists have argued that governments abuse this role to influence the outcome of reports.
Controversy and review after Fourth Assessment Report in 2007
The IPCC came under unprecedented media scrutiny in 2009 in the run-up to the
Copenhagen climate conference
The 2009 United Nations Climate Change Conference, commonly known as the Copenhagen Summit, was held at the Bella Center in Copenhagen, Denmark, between 7 and 18 December. The conference included the 15th session of the Conference of the Parti ...
. This "
Climatic Research Unit email controversy
The Climatic Research Unit email controversy (also known as "Climategate") began in November 2009 with the hacking of a server at the Climatic Research Unit (CRU) at the University of East Anglia (UEA) by an external attacker, copying thousa ...
" involved the leak of emails from climate scientists. Many of these scientists were authors of the
Fourth Assessment Report which came out in 2007. The discovery of an error in this report that the Himalayan glaciers would melt by 2035 put the IPCC under further pressure. Scientific bodies upheld the general findings of the Fourth Assessment Report and the IPCC’s approach. But many people thought the IPCC should review the way it works.
InterAcademy Council review in 2010
The United Nations Secretary-General and the Chair of the IPCC asked the InterAcademy Council (IAC) in March 2010 to review the IPCC's processes for preparing its reports.
The IAC panel, chaired by
Harold Tafler Shapiro, released its report on 1 September 2010.
The IAC panel made seven formal recommendations for improving the IPCC's assessment process. The IPCC implemented most of the review's recommendations by 2012. One of these was the introduction of a protocol to handle errors in reports. Other recommendations included strengthening the science-review process and improving communications. But the IPCC did not adopt the proposal to appoint a full-time executive secretary.
Issues with consensual approach
Michael Oppenheimer
Michael Oppenheimer (born February 28, 1946) is the Albert G. Milbank Professor of Geosciences and International Affairs in the Princeton School of Public and International Affairs, the Department of Geosciences, and the Princeton Environmental Ins ...
, a long-time participant in the IPCC, has said the IPCC consensus approach has some limitations. Oppenheimer, a coordinating lead author of the
Fifth Assessment Report
The Fifth Assessment Report (AR5) of the United Nations Intergovernmental Panel on Climate Change (IPCC) is the fifth in a series of such reports and was completed in 2014.IPCC (2014The IPCC’s Fifth Assessment Report (AR5) leaflet/ref> As ha ...
, called for concurring, smaller assessments of special problems instead of the large-scale approach of previous IPCC assessments.
Others see "mixed blessings" in the drive for consensus within the IPCC. They suggest including dissenting or minority positions.
[Lessons from the IPCC: do scientific assessments need to be consensual to be authoritative?]
Mike Hulme
Michael Hulme (born 23 July 1960) is Professor of Human Geography in the Department of Geography at the University of Cambridge, and also a Fellow of Pembroke College, Cambridge. He was formerly professor of Climate and Culture at King's Coll ...
, in (eds.) Doubelday, R. and Willesden, J. March 2013, pp, 142 ff Others suggest improving statements about uncertainties.
[Do scientific assessments need to be consensual to be authoritative?]
Curry, JA and PJ Webster, 2012: Climate change: no consensus on consensus. CAB Reviews, in press, 2012
Endorsements and awards
IPCC reports are the benchmark for
climate science
Climatology (from Greek , ''klima'', "place, zone"; and , '' -logia'') or climate science is the scientific study of Earth's climate, typically defined as weather conditions averaged over a period of at least 30 years. This modern field of stu ...
. There is
widespread support for the IPCC in the
scientific community
The scientific community is a diverse network of interacting scientists. It includes many " sub-communities" working on particular scientific fields, and within particular institutions; interdisciplinary and cross-institutional activities are als ...
. Publications by other scientific bodies and experts show this.
Many scientific bodies have issued official statements that endorse the findings of the IPCC. For example:
* For the
Third Assessment Report
The IPCC Third Assessment Report (TAR), ''Climate Change 2001'', is an assessment of available scientific and socio-economic information on climate change by the IPCC. Statements of the IPCC or information from the TAR are often used as a referenc ...
in 2001 endorsements came from the
Canadian Foundation for Climate and Atmospheric Sciences
The Canadian Foundation for Climate and Atmospheric Sciences (CFCAS) was Canada's main funding body for university-based research on climate, atmospheric, and related oceanic work. It is now the Canadian Climate Forum. As an autonomous, charitable ...
,
United States National Research Council
The National Academies of Sciences, Engineering, and Medicine (also known as NASEM or the National Academies) are the collective scientific national academy of the United States. The name is used interchangeably in two senses: (1) as an umbrell ...
and
European Geosciences Union
The European Geosciences Union (EGU) is a non-profit international union in the fields of Earth, planetary, and space sciences whose vision is to "realise a sustainable and just future for humanity and for the planet." The organisation has hea ...
.
* For the
Fourth Assessment Report in 2007 endorsements came from the
International Council for Science (ICSU),
and the
Network of African Science Academies The Network of African Science Academies (NASAC) was formed in December 2001 as an independent forum for African science academies to discuss scientific issues of common concern.
Member academies are:
* African Academy of Sciences
* Cameroon Academ ...
.
Nobel Peace Prize in 2007
In December 2007, the IPCC received the
Nobel Peace Prize
The Nobel Peace Prize is one of the five Nobel Prizes established by the will of Swedish industrialist, inventor and armaments (military weapons and equipment) manufacturer Alfred Nobel, along with the prizes in Chemistry, Physics, Physiolog ...
"for their efforts to build up and disseminate greater knowledge about man-made climate change, and to lay the foundations for the measures that are needed to counteract such change". It shared the award with former U.S. Vice-president
Al Gore
Albert Arnold Gore Jr. (born March 31, 1948) is an American politician, businessman, and environmentalist who served as the 45th vice president of the United States from 1993 to 2001 under President Bill Clinton. Gore was the Democratic Part ...
for his work on climate change and the documentary ''
An Inconvenient Truth
''An Inconvenient Truth'' is a 2006 American documentary film directed by Davis Guggenheim about former United States Vice President Al Gore's campaign to educate people about global warming. The film features a slide show that, by Gore's own e ...
''.
Gulbenkian Prize for Humanity in 2022
In October 2022, the IPCC and
IPBES
The Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) is an intergovernmental organization established to improve the interface between science and policy on issues of biodiversity and ecosystem services. It ...
shared the
Gulbenkian Prize for Humanity. The two intergovernmental bodies won the prize because they "produce scientific knowledge, alert society, and inform decision-makers to make better choices for combatting climate change and the loss of biodiversity".
See also
*
*
References
External links
*
IPCC Data Distribution CentreClimate data and guidance on its use.
{{Authority control
International climate change organizations
Organizations awarded Nobel Peace Prizes
United Nations Environment Programme
Working groups
World Meteorological Organization
Environmental organizations established in 1988
Scientific organizations established in 1988
Organisations based in Geneva
Swiss Nobel laureates