New York (CNN Business) A top federal energy regulator appointed by President Donald Trump is calling for urgent action to address climate change.

Wednesday's comments by Neil Chatterjee mark a striking contrast with Trump, who has voiced skepticism about climate change and recently suggested wind power causes cancer — despite no evidence to support that.

"I believe climate change is real. I believe man has an impact," Chatterjee, chairman of the Federal Energy Regulatory Commission, said at a conference in New York. "And I believe that we need to take steps to mitigate emissions urgently."

Chatterjee noted that he is a Republican from Kentucky who worked for Republican Senate Majority Leader Mitch McConnell and was appointed to FERC in May 2017 by Trump . FERC is an independent agency that is run by bipartisan commissioners.

Speaking at the Columbia Global Energy Summit, Chatterjee applauded the rising popularity of cleaner energy such as natural gas as well as wind and solar.

"We've been encouraged and excited to see the increased deployment of renewables," Chatterjee told reporters.

Power emissions drop

Natural gas recently surpassed coal as America's leading fuel source, while wind and solar are expected to be the fastest-growing source of US electricity generation for at least the next two years.

Chatterjee cheered the fact that US power sector carbon emissions have plunged to multi-decade lows . "That's largely being driven, not by regulations, but by market forces. By consumer choices," he said.

That decline in carbon emissions has been caused by power plants switching away from coal in favor of cleaner alternatives.

Neil Chatterjee, the chairman of the Federal Energy Regulatory Commission, said he has "deep, deep sympathy" for coal industries that have been hurt by the shift toward cleaner energy.

Trump promised during the 2016 campaign to revive the downtrodden American coal industry, which has been slammed by the abundance of cheap natural gas. More recently, coal has faced competition from the plunging cost of solar and wind energy. Those trends have continued, if not accelerated, under Trump despite his administration's efforts to slash environmental regulations.

'Devastating' impact on coal country

Chatterjee voiced concern about the demise of coal jobs, but stressed FERC does not have the legal authority to address this problem.

"I have deep, deep sympathy for the plight of coal communities," Chatterjee said. "I'm from Kentucky. I've seen firsthand what happens when the plants shut down and the mines shut down."

The FERC chairman said that many coal regions lack viable alternatives for employment, creating a cascading effect when mines go out of business.

"Homes lose value because people won't move to an area without hope for economic prosperity. That's really devastating," Chatterjee said.

But he said FERC only has the power to "call balls and strikes" based on its statutory authority, not the struggles of coal communities.

"It is up to Congress and state governors to address those issues," Chatterjee said.

In early 2018, FERC unanimously rejected the Trump administration's rescue plan for the crumbling coal industry. Chatterjee joined four other FERC commissioners in dismissing Energy Secretary Rick Perry's proposal to subsidize power plants like coal and nuclear that maintain a 90-day supply of fuel on site.

But Chatterjee said Wednesday he's "very concerned" about the loss of nuclear power, the leading carbon-free source of electricity in the United States. And he noted that the increased use of renewables can cause intermittency issues when solar and wind power isn't as strong.

Leading academics speaking at the Columbia conference agreed with Chatterjee's assessment of climate change as a serious threat.

"99% of the scientific community is totally convinced about climate change," said Alex Halliday, director of Columbia University's The Earth Institute. "It's unambiguous as far as scientists are concerned."