In State of Fear Crichton criticizes a blind belief in anthropogenic
global warming (NOT climate change). In Congo he criticizes scientific
accuracy as a tool for predicting future events. Let's take State of
Fear as an example. Unlike a vast majority of the public, he engages
in constructive criticism, including his sources. Of course, this does
not make him a climatologist, but it certainly does not make his
arguments less valuable and he definitely put more thought into it
than most people.
I am convinced that one could indicate both anthropogenic global
warming and anthropogenic global warming denial as being popular
science. Definitely both ideas are worth looking into. However, I
regret that people get angry about the idea that humans play only a
secondary role in global warming, while not being informed and
bringing forward the argument "well, most scientists think that we are
causing global warming".