IPCC Credibilty damaged

Climate Change Authority Admits Mistake

The error has been traced to the fact that the IPCC permits the citation of non-peer-reviewed sources, called "grey literature," in cases where peer-reviewed data is not available. It requires that these sources be carefully scrutinized, but that didn't happen in this case. The process has "gone spectacularly wrong in this particular instance," Cogley says.

It wasn't carefully scrutinized because the conclusion fit the mindset of these people in which the outcomes of their research are determined before the research is even done.