Guardian Still Hiding The Decline
How do we know how warm or cold it was in the past? | Environment | guardian.co.uk
Growth rings in tree trunks can be wider or thinner depending on the climate at the time of growth, so fossilised trees can reveal the length of growing seasons....
To make their temperature reconstructions as accurate as possible scientists have calibrated each proxy by testing how it changes in response to changing temperature....
A detailed review of Mann’s book: The Hockey Stick and the Climate Wars as it relates to the Wegman report to Congress | Watts Up With That?
Mann then goes on to defend “hide the decline” by saying:
These data show an enigmatic decline in their response to warming temperatures after roughly 1960, perhaps because of pollution21–that is the decline that Jones was referring to.
While “hide the decline” was poor–and unfortunate–wording on Jones’s part, he was simply referring to something Briffa and coauthors had themselves cautioned in their original 1998 publication: that their tree ring density should not be used to infer temperatures after 1960 because they were compromised by the divergence problem.
So the tree ring density proxy has been tested against recent temperatures and failed the test. And yet " Mann now admits his original hockey stick existed solely because of “one set of tree ring records,”
Would you buy a bridge from him?