When House Majority Leader Kevin McCarthy learned of a tape of him saying that “Putin pays” President Trump and Rep. Dana Rohrabacher (R-Calif.), he found the southern California congressman and reminded him: It was just a joke.

Rohrabacher agreed and compared the situation to a lunge at humor that had haunted him for years.

“You have to be very careful when you’re using humor,” Rohrabacher said in a short interview Wednesday evening. “I remember that I was trying to make fun of the scientists who claimed that cow farts make global warming. So at a hearing, I said, oh, do you think the dinosaurs disappeared because of dinosaur flatulence.”

Rohrabacher made that joke 10 years ago, during a hearing on climate change that took place shortly after Democrats won back the House. A climate change skeptic, Rohrabacher asked a group of scientists if they could really, with confidence, say why CO2 levels were higher in the Paleocene-Eocene era.

“We don’t know what those other cycles were caused by in the past,” he said. “Could be dinosaur flatulence, you know, or who knows? We do know the CO2 in the past had its time when it was greater as well.”

Since then, Rohrabacher has been reelected easily — but in 2016, for the first time, his district voted for the Democrats’ presidential candidate, picking Hillary Clinton over President Trump by 1.7 points. Democrats have for the first time worked hard to recruit a credible challenger, and the climate story has been part of their argument.

“Do you know that to this day, you have these environmental wackos saying ‘Dana Rohrabacher believes that flatulence killed the dinosaurs?’” he said. “It was humor, but you’ve got to watch out for it. Kevin didn’t mean any harm.”