Global warming is the new Lysenkoism. Both were political in origin, and never had any scientific support. The anecdotal support wasn't scientific or compelling, but intermittent reinforcement is the hardest kind to beat (as my psychologist buddy said, about something else).
Global warming hasn't got anything to do with UFOs or ETs.
Crichton has better stuff than this.
He didn't say they were related as to substance (what there is), but in scientific methodology (which there isn't). I think this is a great article. I liked his last book "State of Fear".