Former president Bill Clinton, speaking at the Clinton Global Initiative annual meeting, called out climate deniers and their champions in the GOP.

He said, “If you’re an American, the best thing you could do is to make it politically unacceptable to engage in denial. We look like a joke. You can’t win the nomination of one of the major parties in our country if you admit that the scientists are right … It’s really tragic. We need the debate in America, and every country, between people who are a little bit to the right and a little bit to the left about what the best way is to reduce our greenhouse-gas emissions … and we can’t have this conversation because we’ve got to deny it?”

See the video below: