(CNN) A debate over global warming got heated on-air Thursday when CNN contributors Rick Santorum and Jennifer Granholm sparred over whether President Donald Trump should pull the US out of the Paris climate change accord.

Santorum, a former Republican senator from Pennsylvania, argued on CNN's "New Day" that Trump should yank the US from the deal, brokered by former President Barack Obama, a move strongly opposed by other world leaders. The President will announce his decision later Thursday.

"He's got a very big announcement coming up today that's going to be very important to my state, to West Virginia, to Ohio, to Michigan -- it has to do with climate," said Santorum. "If he wants to get on message, he needs to pull out of the Paris climate accord."

But Granholm, a former Democratic governor of Michigan, immediately cut in.

"No, no, no, no, no!" she said. "That is the worst thing!"

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