Character assassination is a favorite tactic they use against those who object.
Check it out:

The debate is over, if there ever was one. Tim Ball argues, with overwhelming evidence, the asserted global warming crisis has been an unmitigated fraud perpetrated by people who no longer have the right to be called scientists. Their collective goal has been to alter society’s future while enriching their own personal lives.

Tracking Major Players
Ball’s book, The Deliberate Corruption of Climate Science, is divided into 13 chapters, each of which opens with a picture of a major player in the historical drama of the corruption of climate science. A few are good guys, such as Richard Lindzen, Michael Crichton, and Vaclav Klaus. Most, however, are villains, including the likes of Maurice Strong, Paul Ehrlich, James Hansen, Michael Mann, Phil Jones, and Al Gore.