The Pope's plea to tackle climate change is likely to get a cool reception from some key energy politicians in the US.
Republican Marsha Blackburn, the second-highest ranking member on the House energy committee, says the jury is still out on global warming.
Pope Francis is to speak on the subject in an address to Congress on Thursday.
He told a White House audience on Wednesday the problem could "no longer be left to a future generation".
Speaking earlier this year as part of a forthcoming Radio 4 documentary series "Climate Change - Are we Feeling Lucky?", she asserted that the earth had cooled in the last 13 years by 1F. And she said no evidence would persuade her of man-made warming.
She also rejected the theory of evolution. Scientists say her views are "complete nonsense".
"The jury is still out saying man is the cause for global warming, after the earth started to cool 13 years ago," she says.
When challenged that the earth's surface temperature had not risen substantially in 13 years - but had definitely not cooled, she said: "I think we've cooled almost 1 degree (F)."
The earth's scientific authorities - including the US space agency Nasa - say the earth is still warming, with ice melting, sea level rising and oceans warming.
Ms Blackburn - who represents Tennessee, a big user of coal - declined to name the sources of her scepticism about mainstream science.
"We have met with different researchers," she says. "We had had numerous committee meetings in which we've had individuals come to present and from all of that and what we have been able to read you come to an opinion.
"There are some that feel like human activity is the cause for carbon emissions and because of that we need to revert to where we were in the 1870s for carbon emissions. I just choose to disagree with that."
Asked what scientific evidence would persuade her that climate change was a threat, she replied: "I don't think you will see me being persuaded."
Asked whether she accepted the theory of evolution she said: "No, I do not."
Ms Blackburn's views matter because Republicans in Congress are trying to roll back President Obama's attempts to cut greenhouse gas emissions.
Professor Brian Hoskins, a leading climate scientist at the Royal Society said her remarks were "absolutely staggering".
"It is nonsense to say the world has cooled," Hoskins said. "If no evidence will persuade Ms Blackburn of climate change, that shows how well-founded her views are."
Correction 25 September 2015: An earlier version of this report implied that Marsha Blackburn's comments were made in relation to the Pope's address. They were actually given in an earlier interview and the headline and text have been amended to make this clear.
Follow Roger on Twitter @rharrabin