Update: I didn't find the source. The closest I found was an article featuring a prominent climate change scientist lamenting about other scientists overstating

Update: I didn't find the source. The closest I found was an article featuring a prominent climate change scientist lamenting about other scientists overstating the issue, on the basis that when people find out it was overblown they would lose trust in whole idea. The scientist herself did not however, overstate the issue - she advocated a conservative approach to communicating with the public.