In an interview on MSNBC’s Morning Joe, GOP frontrunner Donald Trump called President Obama’s position that climate change poses a threat to national security one of the “dumbest statements” ever made in politics.

When pressed on what he would do on climate change as president, Trump responded: “I want to make sure we have clean air and we have clean water,” he said. “That is my thing on climate change.”

“If you’re talking about global warming or climate change, you have to make the whole world behave,” Trump concluded.