Jonathan Chait comments on a popular trend among Republicans who assert “their lack of scientific training as a reason to withhold judgment on anthropogenic global warming.”  

“’I am not a scientist’ makes sense as a way to resolve a tension within Republican politics. It may be a political liability for Republicans to openly associate themselves with the kook conspiracy theories popular among conservative ideologues. One solution might be for Republicans to concede that anthropogenic global warming is indeed real, but that any solution is simply too costly. That might allow Republicans to minimize their kook exposure while still hewing to the bottom line party doctrine that individuals and firms ought to be able to dump carbon into the atmosphere for free.”  

“The beauty of the line is that it implicitly concedes that scientists possess real expertise, while simultaneously allowing you to ignore that expertise altogether.”