Energy Secretary Rick Perry, veering from the Trump administration message on climate change, told CNBC on Wednesday he believes that human activity does play a role.

"I'm on the record as saying the climate is changing. Man, it's been changing forever. Where have you been?" Perry said in a "Squawk Box" interview when pressed on what causes climate change. "The climate is changing. Are we part of the reason? Yeah, it is. I'll let people debate on who's the bigger problem here."

Perry did not quantify whether man-made greenhouse gases associated with climate change, such as carbon dioxide emissions from burning gasoline and coal or methane releases from natural gas and oil production, are the main problem or even whether they're causing the immediate and growing crisis that Democrats contend.

However, Perry did say that it's still worth developing zero-emissions technology and that the Trump administration has made great strides in cleaner energy solutions.

"We're going to address the climate. It makes sense for us to have policies that reduce emissions, that reduce the pollutants that are in the air, to reduce the particles that cause massive health problems around the world," he said. "Common sense tells you, bring the cleaner burning fuels, bring the things that bring the emissions down. That's just common sense."

Perry said the administration is reducing emissions — claiming without evidence or specificity that countries in the Paris climate agreement, with "their hair on fire" when President Donald Trump announced his intention to pull out two years ago, are not doing as much as the U.S.

Trump has repeatedly over the years expressed skepticism about the role humans play in climate change. In 2017, then-Environmental Protection Agency Administrator Scott Pruitt told CNBC he does not believe carbon dioxide is a primary contributor.

On Monday, Trump talked about his administration's environmental record, saying America can lead the world in fighting pollution at the same time it promotes fossil fuels. Since taking office, Trump has dismantled scores of environmental rules. The U.S. has become the world's biggest oil and gas producer over the last couple of years, thanks mainly to a technology-led drilling boom.

During the first round of the second Democratic presidential debate on Tuesday evening, the 2020 hopefuls on the stage all agreed on the need to urgently address climate change, but clashed over how to do it. They also talked about their own proposals to curb what they see as the man-made causes, as well as the merits of the Green New Deal, unveiled in February by Democrats New York Rep. Alexandria Ocasio-Cortez and Massachusetts Sen. Ed Markey.

— Reuters contributed to this report.