SALT LAKE CITY (AP) — U.S. Sen. Mitt Romney said Monday that he believes climate change is happening and human activity is a significant contributor.

During a speech at the conservative Sutherland Institute in Salt Lake City, the senator acknowledged that the position is rare among his fellow Republicans, but one that younger people seem to respond to more strongly than older conservatives.

“In some respects, (by speaking with newer conservatives), I’ll be able to make inroads with some of the young people coming along,” he said.

The former GOP presidential nominee has acknowledged climate change before, saying during his 2018 campaign for U.S. Senate in Utah that “climate realities” will make wildfires more common and destructive in the West. His comments Monday took that stance a step further.

Still, Romney said he’s opposed to the Green New Deal economic package intended to fight climate change, calling it “silliness” in part because much of the growth in emissions is coming from developing countries such as India and Brazil rather than the U.S.

The U.S. should instead provide incentives for entrepreneurs to develop cleaner energy sources while also helping people who work in industries that could be left behind, such as coal mining, he added.

“I’m not willing to sit by if there are major sectors that are losers … and watch people and communities suffer because of that change,” he said.

Romney discussed the benefits of a carbon tax, a fee based on each ton of carbon dioxide emissions produced by fossil fuels that some major oil companies have adopted. He suggested a portion of the tax revenue could go to coal workers in rural communities that would suffer financially from the move to cleaner power alternatives.

The former Massachusetts governor also criticized “Medicare for All” proposals supported by candidates for the Democratic presidential nomination that would put the government in charge of most health benefits.

Romney said the “deeply discounted” Medicare payments would cripple the revenue of “virtually every hospital in rural America.”

On immigration, Romney said he shared the angst of Democrats over family separations at the U.S.-Mexico border, calling it a “very dark chapter” in the country’s history. He stressed the need for tougher border security and a “merit-based system” of legal immigration, but added that Republicans need to agree on a stance before negotiating immigration policies with Democrats.

The senator has yet to endorse a candidate in the 2020 presidential election but has said that Trump will likely win re-election in 2020 as an incumbent presiding over a strong economy.