Crichton makes some interesting points on Global warming, regardless of whether you believe he has cherry picked his data to prove his point. As others have pointed out, the large quantities of data in the book don't mesh too well with the actual story. There is definitely the feeling that you have a normal thriller and a thesis on global warming and they kind of got mixed in the wash. Crichton tries to blend the two, but the result is not perfect.
Spoiler
My real quibble with the book is; why are a large international bunch of well funded, armed and dangerous terrorists being taken on by a small group of mostly unarmed lawyers and later an actor? For the first threat, this sort of works, but as each situation gets bigger and more dangerous, the response looks smaller and more amateur in comparison. They are locating threats by satellite, observing from helicopters, then instead of calling in the Marines, SWAT teams, FBI or an air strike, they go in alone and mostly unarmed. This is just stupid.