This book has a lot of boring politics, but makes up for it with superb explanations of climate science.
Hansen insists he doesn't mean to fear monger, but goes on to use terms like global catastrophe, end of the world, a planet in peril, death of the planet, etc. These emotionally charged terms seem totally out of place in his otherwise sane presentation of scientific information.
He obviously knows little to nothing about biology or astronomy, because he states over and over that all life on Earth will be extinguished by "business as usual", and that Earth will end up similar to Venus. Rising ocean levels, more severe storms: certainly. Sterilization of life: are you kidding? Like Stewart Brand says, "Earth will be fine. It's humans that are in trouble". He also vehemently rejects even the remote possibility of humans settling extra-solar planets. What a pessimist!
Obvious hyperbole aside, it was a good Earth science book. Worth a read.