The book sounds very plausible. Michael Mann is the poster boy for the AGW crowd. It would appear that his most famous creation, the hockey stick, which is still trotted out on the BBC as in the recent Earth: The Climate Wars, is complete bunk and yet we still have posters willing to shoot the messenger. Nice.
One strange omission from the article is the fact the Mann's hockey stick fraudulently mixes two difference types of data: proxy data and real temperature data. This is the essence of the infamous "trick" of Climategate fame. Mann discovered that he had a bit of a problem: his proxy data failed to track the supposed warming post 1961 and actually showed a cooling. A little tricky when what you actually want is a nice big tick like the ones the teacher used to give you to stop you sulking. So, what did he do? He used a "trick" which has been unbelievably defended by AGW supporters the web over, and simply chopped the inconvenient data at 1961 and replaced it with actual thermometer data. Hey presto! A nice hockey stick.
It seems to me that a nice, simple way to resolve this particular issue is to half the amount of money currently given to climate scientists to prove AGW, because that's effectively all that is currently happening. The rest of the money should then be given to other scientists from fields such as applied mathematics, physics, geology, etc., with the explicit remit of tearing apart the science that's emerged from climate science institutes the world over. Of course, they'd have to provide their complete, unexpurgated data, fully documented methodologies, etc., etc. which they currently seem loathe to do. Any climate science that isn't up to scratch should be removed from the scientific record as was the Lancet report on MMR and Autism.
Simple. A deep cleansing of the scientific literature. In the meantime, there should be a moratorium on new taxes, etc., and the IPCC should be disbanded as it is clearly not producing unbiased reporting on the science as it should. A breathing space of, say, 10 years ought to do it. I rather suspect that, long before the 10 years are up, AGW will vanish in a puff of CO2.