Now that Senator Al Franken (D-MN) has decided that it’s safe to be funny again, he’s back with a vengeance. He’s published a new book that’s hilarious — and he’s making a series of videos on climate change. In the kickoff, he offers an insulting analogy between quack doctors and climate-denialists, both of whom would tell a very sick patient what he wants to hear instead of what he needs to hear.

With a weird David Letterman cameo as a bonus.

Just click.