The Intergovernmental Panel on Climate Change (IPCC) is the most authoritative international source on the causes and potential consequences of climate change. It was established in 1988 by the United Nations Environment Programme and the World Metrological Organization and currently has 195 member countries.

The IPCC produces special reports and assessment reports by experts in its member countries who review the existing evidence and research on climate change and identify the strength of scientific agreement. The IPCC First Assessment Report was published in 1990, and it is currently in its sixth assessment cycle, which will produce four reports by March 2023.

Most of the reports of the IPCC are prepared by experts who form three working groups on: the physical science basis; impacts, adaptation and vulnerability; and climate change mitigation.

The latest report: Sixth Assessment Report (AR6)

The contribution of Working Group I to the Sixth Assessment Report, on the physical science basis of climate change, was published in August 2021. The report found that it is “unequivocal” that human activity has warmed the atmosphere, ocean and land, causing “widespread and rapid” changes on a scale that is “unprecedented” over many centuries to many thousands of years. It states that global warming of 1.5°C and 2°C will be exceeded during the 21st century unless deep reductions in emissions occur in the coming decades.

The Working Group II report, published in February 2022, assesses the impacts of climate change on ecosystems, biodiversity and human communities around the world and reviews vulnerabilities and capacities to adapt to climate change. As well as highlighting the adverse impacts, loss and damage to nature and people that are already happening and will intensify, the report makes it clear that inaction on adaptation is a bad strategy.

The following video was produced by LSE and the Grantham Research Institute to coincide with the publication of Working Group II’s report: ‘We can’t afford to wait: why we must adapt to our changing climate now.

The Working Group III report, published in April 2022, examines the different sources of global emissions and provides an assessment of progress on climate change mitigation and the pledges countries have made to cut emissions. It found that average annual greenhouse gas emissions from 2010–2019 were higher than in any previous decade, but the rate of growth during this time was lower than between 2000 and 2009. The report also found that the global greenhouse emissions we will see in 2030 in a scenario where the nationally determined contributions (NDCs) announced prior to COP26 are implemented would make it likely that warming will exceed 1.5°C during the 21st century.

The AR6 Synthesis Report was published in March 2023, completing the Sixth Assessment cycle. This report informed the 2023 Global Stocktake under the United Nations Framework Convention on Climate Change. This is a process for taking stock of how the Paris Agreement is being implemented, to assess progress in achieving the Agreement’s goals.

Contributions from the Grantham Research Institute

Members of the Grantham Research Institute contribute to the work of the IPCC as authors and reviewers of IPCC reports and of other associated papers and literature. Our publications, videos, news and commentaries related to the IPCC and its work can be found here.

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