Two Republican senators launched a new group this week to advocate for “market-based approaches” to environmental problems in the wake of growing momentum among Democrats pushing for an aggressive approach to climate change and other issues.

The formation of the Roosevelt Conservation Caucus — named for Teddy — is an indication of how quickly the politics surrounding climate change and other environmental issues have shifted as Democrats push for aggressive measures like the Green New Deal and voters increasingly recognize the threat of global warming.

Sens. Lindsey Graham of South Carolina and Cory Gardner of Colorado, who are leading the caucus in the Senate along with other Republicans in the House, seemed to acknowledge the new political energy around the environment — without mentioning the Green New Deal explicitly — in a letter seeking the support of their fellow Republicans obtained by TIME. “Republicans have a long history of promoting conservation and environmental protection,” the letter seeking support from GOP colleagues reads. But “these issues have been increasingly hijacked by beliefs in big government solutions and radical environmentalism.”

While the letter appears to reference the Green New Deal, Benji Backer, president of the American Conservation Coalition (ACC), a conservative group focused on the environment that is working with the caucus, says talks around starting the group have been ongoing for more than six months.

Many Republicans in Congress have spent the last decade either ignoring climate change or seeking to chip away at the country’s environmental rules. President Trump has further fueled that fight with his consistent denial of the science of global warming.

Read More: The Green New Deal Could Launch Republican Climate Solutions

But, in recent weeks, some Republicans have started to shift gear, at least rhetorically. Republicans on the House Science and Energy and Commerce committees, for instance, said in hearings that they accepted the science of climate change and declined to call witnesses who sought to undermine it unlike in recent years. Sen. John Cornyn of Texas, the former Republican Whip, tweeted positively about a carbon tax in December. And a slew of GOP elder statesmen have pushed for Congress to embrace such a proposal.

“In Florida, we’ve felt the social and economic consequences of environmental disaster firsthand,” said Rep. Brian Mast, a Florida Republican who’s leading the caucus in the House, in a statement. “It’s necessary that we work together to strengthen conservation efforts and protect our environment.”

It remains to be seen what concrete policy proposals, if any, will follow the shift in rhetoric. The Roosevelt Conservation Caucus does not appear to endorse any specific legislation and the letter does not mention climate change explicitly, instead referring to “environmental stewardship.” And the word conservation in its name suggests that its ambition might be somewhat limited in scope.

Backer suggested that conservation works as a starting pointing for a larger environmental discussion among conservatives. “Conservation is the easiest way to engage on these issues,” he says. “It’s part of our name.”

Still, the battle to engage Republicans remains steep. Many in the party, including President Donald Trump and many members of his Administration, continue to deny the science of man-made global warming, and the Administration last month launched a panel to try to undermine the science. That effort follows a slew of other efforts to roll back environmental rules.

No matter what Trump says, the initiative shows how much the political winds have shifted on environmental issues in recent years. Both Graham and Gardner are up for reelection next year, and Gardner in particular is likely to face a competitive race in a state that is increasingly trending blue. Nearly three-quarters of adults in Colorado and two-thirds in South Carolina think climate change is happening, according to a recent survey from the Yale Program on Climate Change communication. Both states, like the rest of the country, are vulnerable to impacts linked to climate change, including coastal flooding in South Carolina, and drought and wildfires in Colorado.

All these factors mean that some Republicans need to say more. “It’s not going to be enough for a lot of members to say this Green New Deal is a massive socialist program,” Carlos Curbelo, a former Republican representative from Florida, said last month. “I think the next question, ‘is what’s your solution?'”

Write to Justin Worland at justin.worland@time.com.