Sixth Assessment Report of the IPCC

The Sixth Progress Report ( english Sixth Assessment Report , AR6 ; and Sixth World Climate Report ) of the Intergovernmental Panel on Climate Change ( Intergovernmental Panel on Climate Change , IPCC) of the United Nations is to be published, according to momentary planning in the years 2021 and 2022nd As the first part, the report of Working Group I was presented on August 9, 2021, which represents the current state of scientific knowledge.

The reports of the IPCC regularly summarize the current state of scientific knowledge about the influence of mankind on the earth system ( anthropogenic influence) and the resulting feedback (natural influence). Climate change plays a major role here, i.e. the projected consequences of changed Earth system parameters such as the globally averaged surface temperature or the amount of precipitation . The Fifth Assessment Report of the IPCC , published in 2013/14, provides the international community with the basis for most of the environmental and climate-related decisions.

Authors

On April 9, 2018, the IPCC published the author lists of the core team (WGI, WG II, WG III) of the Sixth IPCC Assessment Report. In the core team of 721 experts from 90 countries, 39 main authors and review editors will work in Germany. This means that around a third of those nominated by Germany were selected. Almost 3,000 people have been nominated by governments and observer organizations around the world.

When selecting the experts, the boards of the three working groups (IPCC Bureau) took into account not only the technical expertise, but also the balanced composition of the team of authors with regard to regional origin, the participation of both genders and the collaboration of both IPCC experienced and new experts.

Partial reports

Working group I: The physical basis

The report of Working Group I was 3949 pages long and was published on August 9, 2021. The 42-page Summary for Policy Makers was published during the 54th IPCC session between July 26 and June 6, 2021. Finalized August 2021 and also presented on August 9, 2021. Key messages include:

• The report calls it "clear" that human activities have warmed the oceans, atmosphere and land. Large-scale and rapid changes occurred in the atmosphere, the oceans, the cryosphere and the biosphere. (A.1)
• Between the periods 1850–1900 and 2011–2020, the global mean surface temperature increased by 1.09 ° C (uncertainty range: 0.95 to 1.20 ° C). Each of the past four decades has been warmer than the previous one. (A.1.2)
• With a probability of greater than 66%, the human contribution to this warming of global surface temperature is between 0.8 and 1.3 ° C, with the best estimate being 1.07 ° C. Also with a> 66% probability, well mixed greenhouse gases between 1.0 and 2.0 ° C contributed to the warming between the periods 1850–1900 and 2010–2019, while other human factors such as e. B. Aerosols with> 66% probability led to a cooling between 0.0 ° C and 0.8 ° C. The contribution of natural factors was - 0.1 ° C to + 0.1 ° C and the contribution of natural variability was - 0.2 ° C to + 0.2 ° C. Well-mixed greenhouse gases have a 90 to 100% chance of being the main cause of tropospheric warming since 1979, while stratospheric ozone depletion caused by human activities has a 95-100% chance of being the main cause of stratospheric cooling between 1979 and 1979 Was in the mid-1990s. (A.1.3)
• The past five years have been the warmest since 1850.
• The rate of sea ​​level rise has nearly tripled since 1970.
• Human influence is "very likely" (at more than 90%) the main driver of glacier retreat since the 1990s and arctic sea ice retreat .
• Averaged over the next 20 years, the global mean surface temperature can be expected to rise by more than the 1.5 ° C mark that was part of the Paris Agreement compared to the period 1850–1900 .

Working Group II: Consequences, Adaptation, and Vulnerabilities

The report of Working Group II is to be published after the final assessment (February 14-18, 2022).

Working Group III: Coping with Climate Change

According to the preliminary schedule, the report of Working Group III is to be published after the final assessment (March 21-25, 2022).

Web links

• Sixth IPCC Assessment Report - AR6 - de-IPCC. In: de-ipcc.de. April 9, 2018, accessed August 8, 2019 . 
• Sixth Assessment Report - IPCC. In: ipcc.ch. September 4, 2010, accessed August 8, 2019 . 
• Climate Change 2021. The Physical Science Basis. Summary for Policymakers . IPCC website.
• Climate change widespread, rapid, and intensifying IPCC press release on the publication of the report of Working Group I.
• Climate Change 2021: The Physical Science Basis , Climate Council, summary of the key messages of the report of working group I.

Individual evidence

1. ↑ World's climate scientists to issue strong warning over global heating threat. In: Guardian. August 9, 2020, accessed on August 9, 2020 . 
2. ↑ ^{a b} Sixth IPCC Assessment Report - AR6 - de-IPCC. In: de-ipcc.de. April 9, 2018, accessed August 8, 2019 . 
3. ^ Climate Change 2021. The Physical Science Basis . Intergovernmental Panel on Climate Change, August 9, 2021 (PDF, approx. 250 MB)
4. ↑ IPCC opens meeting to approve physical science report ( English ) IPCC. July 25, 2021. Retrieved August 9, 2021.
5. ↑ Matt McGrath: Climate change: Researchers begin discussions on vital report ( English ) BBC. July 26, 2021. Accessed August 9, 2021.
6. ↑ ^{a b} Matt McGrath: Climate change: IPCC report is 'code red for humanity' ( English ) BBC. August 9, 2021. Accessed August 9, 2021.
7. ↑ Climate change widespread, rapid, and intensifying - IPCC ( English ) IPCC. August 9, 2021. Accessed August 9, 2021.
8. ↑ IPCC WGII ​​AR6 timeline . IPCC website. Retrieved August 9, 2021.
9. ↑ IPCC WGIII AR6 timeline . IPCC website. Retrieved August 9, 2021.