IPCC 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 the available scientific information on climate change. Three Working Groups (WGI, II, and III) covered the following topics: The Physical Science Basis (WGI); Impacts, Adaptation and Vulnerability (WGII); Mitigation of Climate Change (WGIII). Of these, the first study was published in 2021, the second report February 2022, and the third in April 2022. The final synthesis report was finished in March 2023. It served as the scientific foundation for the first Global Stocktake at the 2023 United Nations Climate Change Conference (COP28) and remains the primary baseline for international climate policy and the 2025–2026 revision of Nationally Determined Contributions. The first of the three working groups published its report on 9 August 2021, Climate Change 2021: The Physical Science Basis. A total of 234 scientists from 66 countries contributed to this first working group (WGI) report. The authors built on more than 14,000 scientific papers to produce a 3,949-page report, which was then approved by 195 governments. The Summary for Policymakers (SPM) document was drafted by scientists and agreed to line-by-line by the 195 governments in the IPCC during the five days leading up to 6 August 2021. In the report, there are guidelines for both responses in the near term and in the long-term. According to the report, the main source of the increase in global warming is due to the increase in CO2 emissions, stating that it is likely or very likely to exceed 1.5 °C under higher emission scenarios. According to the WGI report, it is only possible to avoid warming of 1.5 °C (2.7 °F) or 2.0 °C (3.6 °F) if massive and immediate cuts in greenhouse gas emissions are...