Regular readers will know that the infamous Michael Mann Hockey Stick went into the chipper years ago.
The reason was simple. Michael Mann, the climate professor from Kent State, had developed a dataset of climate proxies that demonstrated a Hockey Stick shape. It showed that global temperature had been pretty constant over the last 1,000 years (the shaft), but then suddenly shot up in the last century (the blade). But it turned out that there was a catch. Only a few proxies showed the Hockey Stick signal.
Steve McIntyre of Climate Audit showed, again and again, that if you remove the few proxies with the Hockey Stick signal then you are back to the status quo ante, that the Medieval Warming Period was probably warmer than today.
The Hockey Stick signal was contained in a limited set of bristlecone pines in North America assembled by Donald Graybill and his team. There was also a Tiljander record that the Mannites got upside down (i.e., it showed cooling in the 20th century). Then there was Yamal, worked up by Keith Briffa at the British Climatic Research Unit (CRU).
For years, Steve McIntyre has been trying to get the raw data on the Yamal series, but Keith Briffa wouldn't release it. But he accidentally published his results in a journal (Phil Trans B, Philosophical Transactions of the Royal Society B: Biological Sciences) that required public archiving of data, so McIntyre and others put pressure on the journal to enforce their publication policies. On some day in September 2009, Briffa archived the Yamal data, the tree ring data from Siberia.
And it is a scandal. Briffa cherry-picked about 10 tree-ring cores, and boosted it up with data from 400 km away.
But hey Keith, there's plenty of data near by. Why not use that? Because the data is completely different from the cores that Briffa used and published. If you add that data, the Hockey Stick signal for Yamal disappears.
Go to Climate Audit and take a look. It's breathtaking.
We understand that Keith Briffa is presently ill. We extend our best wishes to him and his family for a swift recovery.