claim: So it’s been a surprise to climate scientists that 2017 has been so remarkably warm — because the last El Niño ended a year ago.
evidence: Mann said, "Ten years ago, the availability of data became quite sparse by the time you got back to 1,000 AD, and what we had then was weighted towards tree-ring data; but now you can go back 1,300 years without using tree-ring data at all and still get a verifiable conclusion."