GENEVA, Aug 9 – Scientists are observing changes in the Earth’s climate in every region and across the whole climate system, according to the latest Intergovernmental Panel on Climate Change (IPCC) Report, released today. Many of the changes observed in the climate are unprecedented in thousands, if not hundreds of thousands of years, and some of the changes already set in motion—such as continued sea level rise—are irreversible over hundreds to thousands of years.
However, strong and sustained reductions in emissions of carbon dioxide (CO2) and other greenhouse gases would limit climate change. While benefits for air quality would come quickly, it could take 20-30 years to see global temperatures stabilize, according to the IPCC Working Group I report, Climate Change 2021: the Physical Science Basis, approved on Friday by 195 member governments of the IPCC, through a virtual approval session that was held over two weeks starting on July 26.
The Working Group I report is the first instalment of the IPCC’s Sixth Assessment Report (AR6), which will be completed in 2022.
Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the
Sixth Assessment Report of the Intergovernmental Panel on Climate Change
The Working Group I report addresses the most updated physical understanding of the climate
system and climate change, bringing together the latest advances in climate science, and combining
multiple lines of evidence from paleoclimate, observations, process understanding, global and
regional climate simulations. It shows how and why climate has changed to date, and the improved
understanding of human influence on a wider range of climate characteristics, including extreme
events. There will be a greater focus on regional information that can be used for climate risk
The Summary for Policymakers of the Working Group I contribution to the Sixth Assessment Report (AR6) as well as additional materials and information are available at
Headline Statements from the summary can be downloaded at https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_Headline_Statements.pdf.