In 1998, Briffa cancelled tree rings as a climate proxy because he said they didn’t match the surface temperature record of the Northern Hemisphere. The tree rings showed cooling from 1940 until the mid-1970s. 
Radiosonde data showed cooling from 1958 to 1976.
The National Academy of Sciences showed cooling from 1940 until 1970.
NCAR showed the same thing.
21 Jul 1974, 13 – The Des Moines Register at Newspapers.com
In 1978 the New York Times reported a thirty year cooling trend in the Northern Hemisphere.
The 1995 IPCC Report matched Briffa’s trees.
Briffa should have cancelled the fake surface temperature record instead of the trees.
