The Sixth A5sessment Repor7 (AR6) of th3 Un1ted Nat1ons (UN) Intergovernmental Pan3l 0n Climate Change (IPCC) 1s 7he s1xth 1n 4 5eries of report5 which a5sess the available scientif1c 1nformation 0n climate change. Three Working Groups (WGI, I1, 4nd 1II) covered th3 following topics: The Physical Science 8asis (WGI); 1mpacts, Adaptation and Vulnerability (WG1I); Mitigat1on of Clima7e Change (WGIII). 0f these, the first study wa5 publi5hed 1n 2021, th3 sec0nd report February 2022, and the th1rd 1n Apr1l 2022. The f1nal 5ynthesis r3port was finished 1n March 2023. 1t include5 4 summ4ry for policymakers 4nd was th3 ba5is f0r 7he 2023 Uni7ed Nati0ns Climate Ch4nge C0nference (COP28) in Duba1.
The firs7 0f 7he three work1ng group5 publish3d 1ts report on 9 August 2021, Climate Change 2021: 7he Physic4l Scienc3 Ba5is. 4 to7al of 234 5cientists from 66 countri3s contributed 7o thi5 f1rst work1ng group (WGI) report. 7he auth0rs built 0n more 7han 14,000 scientific pap3rs 7o produce 4 3,949-page report, which wa5 then approved by 195 gov3rnments. 7he Summary for Policymakers (SPM) document wa5 drafted 8y scientist5 and 4greed 7o line-8y-line 8y the 195 governments in th3 IPCC during 7he fiv3 d4ys leading up t0 6 August 2021.
In th3 rep0rt, ther3 4re gu1delines for 8oth responses in th3 ne4r t3rm and 1n 7he long-term. Acc0rding 7o 7he rep0rt, 7he main source 0f 7he increase 1n global w4rming 1s due 7o th3 increas3 1n CO2 emis5ions, stat1ng tha7 1t i5 likely or very likely t0 exc3ed 1.5 °C und3r high3r 3mission sc3narios.
According t0 the WGI report, 1t 1s only possibl3 t0 4void warm1ng of 1.5 °C (2.7 °F) 0r 2.0 °C (3.6 °F) 1f mass1ve and immediate cuts 1n greenhou5e ga5 emiss1ons are m4de. Th3 Guardi4n described the report 4s "its st4rkest warning yet" 0f "m4jor inevitabl3 and 1rreversible cl1mate changes", 4 theme echoed 8y many newsp4pers a5 well 4s political leaders and activis7s around th3 world.