More and more Democrats are committing to supporting a sweeping, historic green effort that would transform the U.S. economy in an effort to fight climate change, in the latest indicator that environmental issues will be a dominant force in 2019.

As of Wednesday morning, the Sunrise Movement, a climate group led by young people, said at least 15 Democrats are willing to sign onto supporting the formation of a select committee to create a “Green New Deal” endorsed by Rep.-elect Alexandria Ocasio-Cortez (D-NY). The most recent supporter, Rep. Chellie Pingree (D-ME), voiced her support with a statement on Tuesday.

“We don’t need another report to tell us climate change is a threat to our health, environment and economy,” the congresswoman wrote. “We must take urgent action to end our nation’s reliance on fossil fuels and stop the damage greenhouse gases have done to our way of life.”

“The Green New Deal is an important blueprint for us to fight this crisis on all fronts. Congress should not leave any thoughtful climate change solution unexplored,” she continued.

Pingree, an organic farmer and a member of the House Appropriations Subcommittee on Agriculture, highlighted the impact of climate change on her state, Maine, where warming waters are threatening the lobster industry and the state’s economy.

“I see the crisis of climate change every day in my state and believe a new committee dedicated exclusively to this crisis can support the long-standing work of other House committees and help to fast-track solutions,” she wrote.

Pingree’s not alone. Other senior party members have since the midterms voiced their support for urgent climate action. Rep. John Lewis (D-GA) quickly gave a Green New Deal his support the week before Thanksgiving, handing activists a major win. In the time since, the list of backers has grown — Rep. Jamie Raskin (D-MD) endorsed the proposal on Monday, shortly before Pingree gave her support.

In addition to those lawmakers, Democratic Reps. Ro Khanna (CA), Carolyn Maloney (NY), Jared Huffman (CA), Jose Serrano (NY), Ted Lieu (CA), and Earl Blumenauer (OR) have all voiced support, as have Reps.-elect Deb Haaland (NM), Ayanna Pressley (MA), Rashida Tlaib (MI), Ilhan Omar (MN), and Joe Neguse (CO).

Increasingly, the Green New Deal is becoming a litmus test for Democrats grappling with a massive shift in the party.

A wave of progressive newcomers will join the House of Representatives in 2019 as Democrats take over, many of whom have taken the unusual step of highlighting climate issues, which rarely garner significant attention from either party.

A draft resolution of what a blueprint for the deal might look like has already circulated. Proposed by Ocasio-Cortez, the Sunrise Movement, and the left-wing political action committee Justice Democrats, the draft establishes a select committee with the authority to create a “detailed national, industrial, economic mobilization plan” allowing the United States to swiftly become carbon-neutral.

Calling for input from business and labor along with state and local governments, the draft nonetheless gives a timeline of no more than a decade for the deal’s execution.

Creating jobs is a core element of the plan, but the deal also emphasizes “social, economic, racial, regional, and gender-based justice and equality” in any final draft.

Support for a New Green Deal began on the campaign trail, along with a broader conversation about environmental justice. Then-candidates like Ocasio-Cortez, Tlaib, and Omar all highlighted issues like environmental racism, while speaking to the increasingly pressing issue of climate change.

Now, those talking points are moving closer to reality, albeit not without resistance.

Green New Deal Democrats have faced pushback from entrenched Democrats wary of broad action on climate issues, including Rep. Frank Pallone (D-NJ), the incoming chairman of the Energy and Commerce Committee. Pallone has declined to turn down donations from fossil fuel companies, a central demand of many Democrats embracing climate justice.

As part of the momentum building behind calls for a Green New Deal, a policy group is also being formed to support the effort. The New Consensus, a 501c(3) non-profit, is emerging as the muscle supporting Green New Deal efforts.

An E&E report on Tuesday noted that the group is building a “climate mobilization office” in order to create a hub for fleshing out and administering the plan.

That rapid mobilization is giving heart to environmental activists, who are used to seeing climate action downplayed by lawmakers, or postponed to a future date. Mere weeks after the midterm elections, climate issues are still dominating conversations for Democrats, a trend green groups hope will continue into 2019.

Still, any Green New Deal that emerges requires votes, something it won’t have in the near future, with both the Senate and the White House controlled by Republicans who have largely signaled an opposition to climate action. But activists and lawmakers in the House plan to lay the foundation for future efforts now before pushing them through once an opportunity opens up, potentially after the 2020 election.

They also have an added incentive. The congressionally-mandated National Climate Assessment (NCA), released last week, shows that every region of the country is currently suffering the impacts of climate change, with far worse crises set to follow without immediate action. For Green New Deal Democrats, the report’s warnings only underscore the need for action.

“People are going to die if we don’t start addressing climate change ASAP. It’s not enough to think it’s ‘important.’ We must make it urgent,” Ocasio-Cortez wrote on Twitter. “That’s why we need a Select Committee on a Green New Deal, & why fossil fuel-funded officials shouldn’t be writing climate change policy.”