The Working Group I contribution to the Sixth Assessment Report is the most up-to-date 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, and global and regional climate simulations.

Climate change has already caused “substantial damages and increasingly irreversible losses, in terrestrial, freshwater and coastal and open ocean marine ecosystems”.

The 6th Assessment report by IPCC

Among the findings, the report concludes that:

• Climate change has already caused “substantial damages and increasingly irreversible losses, in terrestrial, freshwater and coastal and open ocean marine ecosystems”.
• It is likely that the proportion of all terrestrial and freshwater species “at very high risk of extinction will reach 9% (maximum 14%) at 1.5C”. This rises to 10% (18%) at 2C and 12% (29%) at 3C.
• Approximately 3.3 to 3.6 billion people “live in contexts that are highly vulnerable to climate change”.
• Where climate change impacts intersect with areas of high vulnerability, it is “contributing to humanitarian crises” and “increasingly driving displacement in all regions, with small island states disproportionately affected”.
• Increasing weather and climate extreme events “have exposed millions of people to acute food insecurity and reduced water security”, with the most significant impacts seen in parts of Africa, Asia, Central and South America, small islands and the Arctic.
• Approximately 50-75% of the global population could be exposed to periods of “life-threatening climatic conditions” due to extreme heat and humidity by 2100.
• Climate change “will increasingly put pressure on food production and access, especially in vulnerable regions, undermining food security and nutrition”.
• Climate change and extreme weather events “will significantly increase ill health and premature deaths from the near- to long-term”.

The report warns that if global warming passes 1.5C – even if overshooting that global average temperature temporarily before falling back again – “human and natural systems will face additional severe risks”, including some that are “irreversible”.

Use the following links to read more

• By IPCC
  • AR6 Climate Change 2021: The Physical Science Basis
  • AR6 Climate Change 2022: Impacts, Adaptation and Vulnerability
• By others
  • IPCC report: ‘Code red’ for human driven global heating, warns UN chief by UN
  • In-depth Q&A: The IPCC’s sixth assessment on how climate change impacts the world by Carbonbrief.org