Oregon State Sen. Herman Baertschiger Jr., who leads the Senate Republican caucus that staged a walkout this year to help kill a big climate bill, faces new criticism for saying in a social media post that humans have only played a “minor role” in the planet’s warming temperatures.

The Grants Pass legislator wrote a post on his Facebook page this week criticizing the International Panel on Climate Change's reports on the subject. He said many factors play into global warming, including "the sun, orbital variations, clouds and oceans."

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I first gave this opinion piece to the Grants Pass Daily Courier, but the editor refused to publish it due to a difference of opinion #interesting https://t.co/DeRUHHgIeR — Herman Baertschiger (@SenBaertschiger) October 2, 2019

Baertschiger said there “is no evidence” that man-made carbon emissions are a dominant cause of warming temperatures. “Current science says that human-created CO2 has only played a minor role in the planet’s recent warming,” he wrote.

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The GOP lawmaker came under fire from Oregon House Majority Leader Barbara Smith Warner, D-Portland. She said on Twitter: “Your insistence that you believe ‘climate change is real’ is undercut when you spout #climatechangedenial talking points.”

In an interview, Baertschiger wavered when it came to defending his post, which he wrote in response to last month’s global climate strike by student activists.

He told OPB that he’s “somewhere in the middle” on the issue of whether human activities have anything to do with climate change.

“I’m thinking to myself, we’ve got 7 billion people living on the planet, it’s got to have something to do with it,” he said, adding that, “I don’t know if it’s the dominant factor or it’s just amplifying” natural changes.

David Wrathall, an assistant professor of natural hazards at Oregon State University, is a lead author for the International Panel on Climate Change. He said the panel’s scientific reports show an “unequivocal link” between human activities and warming temperatures.

“That’s the scientific consensus,” Wrathall said. He added that the panel’s work includes massive amounts of work involving thousands of hours and expensive monitoring of the earth and its atmosphere.

Baertschiger and his GOP colleagues staged a nine-day walkout in June to keep Democrats from passing a bill aimed at capping carbon emissions from many industrial and transportation sources in Oregon. Democratic legislative leaders said they intend to bring the issue back in next February's legislative session.