According to a 2014 survey, half of people in the world haven’t heard of the Holocaust. Among the other half, about one- third don’t believe it actually happened. They think it’s a lie or a hoax, spread by Jews and their allies to promote pro-Israel sentiment and other political agendas.

And since there’s such wide disagreement on whether there was a Holocaust, we should debate the question in our schools. Right?

Wrong. Although there are lots of Holocaust deniers out there, the best-informed people know that it happened. We shouldn’t pretend that there’s a real debate about it, which gives the deniers more credence than they deserve.

And that brings us to climate change and Oklahoma Attorney General Scott Pruitt, Donald Trump’s nominee to head the Environmental Protection Agency. In an article published earlier this year, Mr. Pruitt maintained that human-made climate change should be presented as a question rather than a fact.

“Scientists continue to disagree about the degree and extent of global warming and its connection to the actions of mankind,” Mr. Pruitt wrote. “That debate should be encouraged — in classrooms, public forums, and the halls of Congress.”

Mr. Pruitt is correct about the extent of climate change, which scientists continue to debate. But there is no debate about whether it’s connected to human behavior. Questioning that premise is akin to questioning whether the Holocaust happened, because almost all credible expertise lies on one side. It’s not — or shouldn’t be — a question at all. ...