An amazing story of scientific fraud. Probably the biggest scientific fraud in history.
As of 1975, both the instrumental and the tree ring data showed sharp cooling from 1940 to 1970
The next graph overlays Briffa’s trees on the 1975 National Academy of Sciences graph. There was almost a perfect match, with no divergence.
NOAA radiosonde data from the 1950’s through the 1970’s also showed sharp cooling and no divergence from Briffa’s trees.
The New York Times reported a unanimous consensus of scientists for global cooling
None of this fit the global warming agenda, so the hokey team simply changed the temperature record to “remove the 1940’s blip” and eliminate the post-1940 cooling. Altering the data is what caused the divergence. There was no divergence prior to the data tampering.
After massively altering the temperature record, they were then able to delete Briffa’s trees – by pointing out that Briffa’s trees didn’t match the massively altered surface record. Deleting Briffa’s trees (hiding the decline) opened the door for Mikey to make his Hokey Stick, and an even larger bonus was that it gave the team an excuse to turn the US cooling trend into a warming trend – because it didn’t match their massively altered global temperature trend.
Then the final kicker was blaming their data tampering on CO2 corrupted tree rings, and naming it the “divergence problem”.
The CO2 excuse for hiding the decline is quite remarkable, because increased CO2 would create a fake warming bias in the tree rings, not a cooling bias. The logic behind their divergence claim is nonsensical.
Some skeptics believe they are being good citizens, by playing nicely with the crooks behind this fraud.