Dr. James Hansens "Wall Street Journal" Letter

I read Dr. Hansens' letter to the editor of the Wall Street Journal over lunch in which he claims that doubling CO2 will result in atmospheric warming of 2.2 to 4.8°C. His letter was written to criticize an article by Matt Ridley that estimates the atmospheric response to doubling at at the lower rate of 1.5°C (I agree with this value or slightly less).

The problem is that Dr. Hansen's own data does not back up his contention (scroll down to middle of page).

Above is a simplified version of Dr. Hansen's data (you can compare by looking at the values of the original figure in the middle of the page).

In 1988, Dr. Hansen published a paper where he forecast 2012 temperatures to be in the range of the green and blue lines. I have highlighted those values with a red oval. He also forecast temperatures if the Kyoto treaty had been immediately ratified and CO2 levels started to drop. That is the purple line.

Actual world temperatures -- as calculated by Dr. Hansen himself (the black line) -- are below even the level he was expecting if Kyoto had been ratified. 

There is a lot of cognitive dissonance in climate science as actual conditions increasingly diverge from what has been forecast. Dr. Hansen's letter is the latest example.