In August 2021, 33 years after its creation, the scientists of the IPCC (Intergovernmental Panel on Climate Change) warn once again in their 6th report (AR6) on the physical basis of climate change (IPCC Group I) about climate change, already underway, and about the changes to come.
Since their last report in 2013, the science has consolidated and the scientists state this unequivocally in the very first statement in the Summary for Policymakers: "It is unequivocal that human influence has warmed the atmosphere, ocean and land. Widespread and rapid changes in the atmosphere, ocean, cryosphere and biosphere have occurred."
The Summary for Policymakers is divided into 4 parts:
The current state of climate change where one of the novelties of this report is the regional approach to climate change which gives important insights into the observed climate differences since the 1950s across the world.
Possible future climates where the climate consequences of 5 different scenarios of GHG emissions to the atmosphere are analyzed. According to the simulations of the 5 scenarios, the higher the cumulative CO₂ emissions to the atmosphere, the lower the proportion of CO₂ emissions captured by land and ocean.
Regional risk assessment and adaptation, where scientists assess how the climate responds to both human influence and natural factors and their internal variability. But scientists warn that while natural factors and internal variability will modulate human-induced changes, particularly on a regional scale and in the short term, this will have little effect on the temperature increase by 2100. However, the impacts of climate change will be greater at 2°C than at 1.5°C, and even greater if the temperature exceeds 2°C, in all regions of the world.
In the final section of the report entitled "limiting future climate change", the scientists insist, "every tonne of CO₂ emissions adds to global warming" and state, "From a physical science perspective, limiting human-induced global warming to a specific level requires limiting cumulative CO2 emissions, reaching at least net zero CO2 emissions, along with strong reductions inother greenhouse gas emissions."
Link to the Summary for Policymakers
Link to the AR6 report
Link to Mediapart
Link to Reporterre
Link to France Culture
The next IPCC reports from Panel II on impacts, adaptation and vulnerability, and Panel III on mitigation of climate change are due in February and March 2002, before the synthesis report in September 2022.