From the NY Times........
The issue involved an effort to reconstruct the climate history of the past several thousand years using indirect indicators like the size of tree rings and the growth rate of corals. The C.R.U. researchers, leaders in that type of work, were trying in 1999 to produce a long-term temperature chart that could be used in a United Nations publication.More.....
But they were dogged by a problem: Since around 1960, for mysterious reasons, trees have stopped responding to temperature increases in the same way they apparently did in previous centuries. If plotted on a chart, tree rings from 1960 forward appear to show declining temperatures, something that scientists know from thermometer readings is not accurate.
Most scientific papers have dealt with this problem by ending their charts in 1960 or by grafting modern thermometer measurements onto the historical reconstructions.
No comments:
Post a Comment