One might think language matters to a law prof, but apparently not so with Herr Doktor Professor. Rather we should excuse silly things Ron Johnson says about global warming because he's a businessman, dammit, not an academic, politician or lawyer (like Rick!).
But as Jim Spice points out in comments, that's hardly a defense:
If Johnson is the caliber of businessman his supporters say he is, he should have the skill set to read and analyze a spreadsheet. The same skills could be put to use to understand the science behind AGW (which already does, by the way, take into consideration "other impacts on the climate such as solar activity").
Given his disregard for the scientific consensus, either he is not the businessman he makes himself out to be, or he is stating something he does not believe for political purposes.
I suppose there could be a third possibility, that he has not looked at the data and feels qualified to comment authoritatively nonetheless.
None of these three instances seem particularly confidence instilling to me.
The scary truth may be is that all Ron Johnson knows about politics he learned from talk radio. Certainly as a CEO of a company that had 70% of its business with his father in law, he had time for such luxuries.