Energy Secretary Rick Perry on Tuesday called for an intellectual debate on humans’ role in climate change, saying he still does not believe the science is settled.

Perry acknowledged during a White House briefing the climate is changing and man is having an impact on it, but it “is not settled science.”

“Here’s what I believe, and I’m pretty much on the record, but I love getting the opportunity to talk about it again: The climate is changing. Man is having an impact on it,” Perry said even though he said as recently as last week he does not believe carbon dioxide emissions are a major driver despite the consensus among climate scientists.

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“I mean, what is the other side?” Perry asked. “The people who say ‘the science is settled. It’s done. If you don’t believe that, you’re a skeptic. A luddite.’ I don’t buy that. This is America. Have a conversation. Let's come out of the shadows of hiding behind your political statements and let’s talk about it. What’s wrong with that? And I’m full well – you know, I can be convinced. But why not, let’s talk about it.”

President Donald Trump has called climate change a hoax perpetrated by China to give it a leg up economically, and just weeks ago he pulled the United States out of the Paris Climate Agreement. Environmental Protection Agency Administrator Scott Pruitt has said he does not believe carbon dioxide is a major factor in global warming. Among the administration’s first acts were the removal of pages on climate change from the White House and EPA websites.

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The planet’s average surface temperature is about 2 degrees higher than it was in the late 19th century and scientists say the change was largely driven by increases in greenhouse gases, NASA has said.

Perry said he doesn’t know what Trump’s position on climate change is but that the goal is to make the United States self-reliant when it comes to energy. He also said he is reaffirming “our commitment to clean energy.”

Perry’s comments follow release of a study indicating the ice sheets in Greenland and Antartica are melting much more quickly than in the past, leading to rising sea levels that will threaten coastal areas.

Rising temperatures also are causing an increase in acidity in the Mediterranean Sea, leading to worries about the extinction of native species. The Mediterranean’s temperature and acidity is rising faster than that of other oceans, researchers from the Villefranche-sur-Mer oceanographic laboratory in the south of France found.

NASA and the National Oceanic and Atmospheric Administration reported earlier this year Earth’s 2016 surface temperatures were the warmest on record, the third record year in a row, and globally, temperatures were 1.78 degrees warmer than the mid-20th century.

“The 2016 temperatures continue a long-term warming trend, according to analyses by scientists at NASA’s Goddard Institute for Space Studies (GISS) in New York. NOAA scientists concur with the finding that 2016 was the warmest year on record based on separate, independent analyses of the data,” NASA said.

“We don’t expect record years every year, but the ongoing long-term warming trend is clear,” said Gavin Schmidt, director of the Goddard Institute for Space Studies.