,
4 tweets,
1 min read
Read on Twitter
I'm dipping my toes into new PAGES2019 reconstruction. Noticing that a "new" tree ring chronology in northern Canada had a pronounced hockey stick, I looked at underlying paper. Many of the trees had classic "divergence" problem i.e. tree ring widths went down with warmth 
2/ authors had calculated a chronology using all trees yielding result that wasn't alarming. So, following in tradition of Mann and Briffa "hiding the decline", they deleted the 20th century portion of those trees that didn't go up enough in 20th century and calculated
3/ "divergence-free" chronology without declining trees, which unsurprisingly, went up like a champ. Needless to say, PAGES2K used the hockey-stick shaped "divergence-free" chronology. The cherry-picking and cheating in this field is not just at the stage of multiproxy screening
4/ but even in the underlying papers. If anything, practices are even worse now than 10-15 years ago. However, the swamp "scientists" are far too stubborn to concede that these tree ring and even worse tree ring+short coral reconstructions are worthless.
