Sunday, October 17, 2021

IPCC 6: Drought

I have now looked through all of the latest IPCC report. I say “looked through” because the report, including the Summary for Policymakers, is huge, just under four thousand pages. I looked over all of it, read only bits of particular interest to me.

One complication in writing about it is that the main report has, across every page in large light grey letters, “ACCEPTED VERSION SUBJECT TO FINAL EDITING,” and at the bottom of every page, “Do Not Cite, Quote or Distribute.” I will limit myself to describing what is in it and where but not actually quoting. The restriction is not present in the Summary for Policymakers, however.


Climate change is often blamed for recent droughts in a variety of places. That claim was supported by the fourth IPCC report but retracted in the fifth, so I was curious what the sixth said about it. 

The answer is complicated. The summary contains the figure shown below. It divides the world into 45 regions and reports for each on both confidence that drought had increased (or decreased) and confidence that there was a human contribution to the change. Yellow hexagons are regions where there is at least medium confidence in increased drought, green of decreased. One dot indicates low confidence in human contribution, two dots medium confidence, three dots (of which there are none) high confidence.