That's in the Old Testament?

Not that it isn't true, of course.

Pope blasts climate change doubters: cites moral duty to act

Pope Francis has sharply criticized climate change doubters, saying history will judge those who failed to take the necessary decisions to curb heat-trapping emissions blamed for the warming of the Earth.

Francis was asked about climate change and the spate of hurricanes that have pummeled the U.S., Mexico and the Caribbean recently as his charter plane left Colombia on Sunday and flew over some of the devastated areas.

"Those who deny this must go to the scientists and ask them. They speak very clearly," he said, referring to experts who blame global warming on man-made activities.

. . . .

For those who have denied climate change, or delayed actions to counter it, he responded with an Old Testament saying: "Man is stupid."

Not finding it at the Bible Gateway.

I get several hits on "stupid", but none on "man is stupid".