IPPC Sixth Assessment Report: The Most Severe Climate Change Warning Yet

IPCC

The Intergovernmental Panel on Climate Change (IPCC) released the primary of three instalments of the sixth assessment report (AR6) on Aug. 9, 2021. The IPCC is a body of the United Nations, responsible for advancing and assessing the science related to human-induced climate change. 

The current IPCC Chair, Hoesung Lee, said, “The Sixth Assessment Report will update our knowledge on climate change, its impacts and risks, and possible response options, and play an important role in implementing the Paris Agreement.” This instalment of the report summarizes the physical science basis by pulling together findings from over 14,000 peer-reviewed studies. 

Climate change is defined as long-term changes in temperature and weather patterns for Earth’s regional and global climates due to human influence. The sixth assessment report serves as an undeniable warning of irreversible changes to the climate. The first instalment covers the physical science basis which has been divided into parts: A. The Current State of the Climate; B. Possible Climate Futures; C. Climate Information for Risk Assessment and Regional Adaptation, and D. Limiting Future Climate Change. Since the fifth assessment report, there have been new analyses, climate model simulations, and other methods combining evidence for an improved understanding. 

The report concludes that it is “unequivocal” that human influence has warmed the land surface, oceans, ice, and atmosphere of the planet as a cause of “widespread and rapid” changes. Many of these climate changes are irreversible and abrupt. IPCC author, Prof. Ed Hawkings of the University of Reading, said, “We’re already experiencing climate change, including more frequent and more extreme weather events.” The links between human-induced warming and extreme weather have become more apparent since the last report. The authors say that it is now an “established fact”. The evidence provided of these changes includes heat waves and droughts, and heavy precipitation. In almost all emission scenarios, warming of 1.5°C and 2°C is exceeded in the 21st century unless drastic reductions occur. However, the report does show that net-zero works for stabilizing and even reducing the surface temperature. The other two instalments are planned to be published in 2022. 

To guarantee neutrality, the IPCC does not do its own research, but simply collects it in one place. The report released is a synthesis of all the relevant information volunteer IPCC scientists have found in the thousands of scientific papers released each year. Although the IPCC is not directly responsible for the original collection of data, it does have processes unique to its own organization. While creating reports, the IPCC collects and writes about information from other research studies. One of the essential parts of the IPCC process of creating a report is the reviewing stage. The report is reviewed by scientists employed by the IPCC. “Working Groups, members of the author teams, governments, IPCC observer organizations, and other organizations can all encourage experts to register as reviewers, facilitating the participation of experts encompassing as wide a range of views, expertise and geographical representation as possible.”