So, "defect" and "enemy camp." It's official now -- the global warming controversy isn't a debate, it's an out-and-out war:
One of the world's most eminent climate scientists - for several decades a warmist - has defected to the climate sceptic camp.
Lennart Bengtsson - a Swedish climatologist, meteorologist, former director of the Max Planck Institute for Meteorology in Hamburg and winner, in 2006, of the 51st IMO Prize of the World Meteorological Organization for his pioneering work in numerical weather prediction - is by some margin the most distinguished scientist to change sides.
For most of his career, he has been a prominent member of the warmist establishment, subscribing to all its articles of faith - up to and including the belief that Michael Mann's Hockey Stick was a scientifically plausible assessment of the relationship between CO2 emissions and global mean temperature.
[. . .]
"I have used most of my career to develop models for predicting the weather. I have learned the importance of forecasting validation, i.e. the verification of predictions with respect to what has really happened. So I am a friend of climate forecasts. But the review of model results is important in order to ensure their credibility. It is frustrating that climate science is not able to validate their simulations correctly. The warming of the Earth has been much weaker since the end of the 20th century compared to what climate models show."
I have great respect for the scientific work that goes into the IPCC reports. But I see no need for the endeavour of the IPCC to achieve a consensus. I think it is essential that there are areas of society where a consensus cannot be enforced. Especially in an area like the climate system, which is incompletely understood, a consensus is meaningless.
I wouldn't say he's gone over to "the other side" but rather than he's regained a proper respect for science and the skepticism that should attend it. If it's true that the right tries to ignore science (which of course it isn't), it must be said that the left tries to co-opt it. No unproveable claim of dire consequences is too outrageous if it advances the statist agenda.
