obtained video of Barton speaking to the House Subcommittee on Energy and Power in support of the Northern Route Approval Act, a bill that could allow Congress to override President Barack Obama if he refuses to approve the controversial Keystone XL pipeline extension.

"I don't think it's a secret that I'm a proponent and supporter of the Keystone pipeline," Barton explained.

In contrast to Barton's past insistence that global warming science is "pretty weak stuff," the Texas Republican took a different tack in Wednesday's hearing.

"I don't deny that the climate is changing," he said. "I think you can have an honest difference of opinion on what's causing that change without automatically being either all-in that it's all because of mankind or it's all just natural. I think there's a divergence of evidence."

"I would point out if you're a believer in the Bible, one would have to say the Great Flood is an example of climate change. And that certainly wasn't because mankind overdeveloped hydrocarbon energy."