David J commented yesterday at this blog that,
It would seem the Hockey Stick “debate” is fast going the same way as the MSU “debate”.
I understand David’s comment to mean that more data and analysis is confirming that current warming is ‘unnatural’ and a consequence of global warming from greenhouse gases.
But the following comment from Richard Lindzen (see the second reason), sent as a letter to Benny Peiser, has got me
The concern over the hockey stick has always struck me as weird. There are several reasons for my impression:
1. There is no doubt that Europe and the North Atlantic were warmer than they are today for several centuries during the high middle ages. This is more than enough information to tell us that major climate changes can occur without the present level of industrialization — regardless of what happened to the global mean temperature.
2. Indeed, if the global mean temperature did not change while Europe and the North Atlantic underwent very substantial warming, this would imply a major change in the geographic pattern of
temperature. However, a major assumption in the hockey stick is that the patterns remain fixed. One is then left with the paradoxical conclusion that if the hockey results are right, the hockey stick analysis is wrong.
3. The medieval warm period in Europe was a period of high population, vibrant intellectual activity, and an absence of famine and plague. The onset of the little ice age was marked by famine, plague, and much reduced population. This suggests that warmth wasn’t all that bad. At the same time, the Renaissance and the intellectual flowering that followed all occurred before the end of the little ice age, suggesting that human abilities can rise above the problems posed by the environment.
In many ways, the whole story can be regarded as encouraging. Yet we focus on a couple of tenths of a degree in the global mean.
Richard S Lindzen is Alfred P. Sloan Professor of Meteorology, Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology. For more information visit http://www-eaps.mit.edu/faculty/lindzen.htm .
Letter republished with permission from Benny Peiser.