Even though their behavior may well prove destructive, IMO not all AGW proselytizers are malevolent or cynical–but some are, obviously; among the ones who are, not all started that way. As for ‘ignoramus’:

As we have said, it defies common sense that going from a carbon dioxide concentration of 280 parts per million to 380 parts per million threatens catastrophe when such larger forces are at work.

To my eye, this sentence seems a bit wide-ranging. Doesn’t it defy common sense that the force which makes a dropped pencil fall is also the force the keeps the moon near the Earth? Doesn’t it defy common sense that a portable amount of a heavy metal can explode to devastate a city?

If this is accurate, the original usage of ‘ignoramus’ is just the attitude that’s needed wrt anthropogenic global warming:

If you’ve ever studied Latin, you might recognize “ignoramus” as a first-person plural verb meaning “we don’t know.” In fact, that’s about all it meant until the 16th century when grand juries in England began writing “ignoramus” across the backs of indictments whenever they decided there was insufficient evidence to warrant prosecution.

“Ignoramus” might have remained strictly a legal term if playwright George Ruggle hadn’t come along. In 1615, he wrote a satire called “Ignoramus,” jokingly named after the play’s main character, a lawyer who actually knew nothing about law. Ruggle wrote his play, the Oxford English Dictionary says, “to expose the ignorance and arrogance of the common lawyers.” Soon the name of “Ignoramus” the lawyer was commonly applied to anyone ignorant.

IMO, ‘insufficient evidence to warrant prosecution’ is spot on. As has been discussed at Dinocrat, we don’t understand climate change well enough to justify reconfiguring civilization–with the attendant economic distortion, retarded progress, and prolongation of global poverty.

Climate change is a serious concern. It is a reasonable goal that, say by the end of the century, humanity have developed the capability to make minor adjustments to the planetary environment. Basic and applied research should be funded. But it is only, um, common sense that political, economic, and technological tweakings of the ecosystem be engineered to be reversible.