Sen. Bernie Sanders (I-Vt.) on Sunday reiterated his claim that climate change will lead to terrorism by destabilizing regions affected by droughts, floods, and other natural disasters.

“The reason is pretty obvious: If we are going to see an increase in drought and flood and extreme weather disturbances as a result of climate change, what that means is that peoples all over the world are going to be fighting over limited natural resources,” Sanders said on CBS’s “Face the Nation.”

“If there is not enough water, if there is not enough land to grow your crops, then you’re going to see migrants of people fighting over land that will sustain them, and that will lead to international conflict,” he added.

The Democratic presidential hopeful raised eyebrows when he made the claim at the second Democratic primary debate on Saturday.

The self-proclaimed Democratic socialist said on Sunday that the attack on Paris is an early example of this phenomenon playing out.

“Well what happens in, say, Syria… is that when you have drought, when people can’t grow their crops, they’re going to migrate into cities,” Sanders said.

“And when people migrate into cities and they don’t have jobs, there’s going to be a lot more instability, a lot more unemployment, and people will be subject to the types of propaganda that al Qaeda and ISIS are using right now,” he added.

“So where you have discontent, where you have instability, that’s where problems arise, and certainly, without a doubt, climate change will lead to that.”

The Sanders campaign reportedly sparred with CBS over the network’s decision to refocus the Democratic debate on foreign policy in the wake of the terrorist attack in Paris on Friday.