WASHINGTON — Liberal Democrats put flesh on their “Green New Deal” slogan Thursday with a sweeping resolution intended to redefine the national debate on climate change by calling for the United States to eliminate additional emissions of carbon by 2030.

The measure, drafted by freshman Rep. Alexandria Ocasio-Cortez, D-N.Y., and Sen. Ed Markey, D-Mass., is intended to answer the demand, by the party’s restive base, for a grand strategy that combats climate change, creates jobs and offers an affirmative response to the challenge to core party values posed by President Donald Trump.

The resolution has more breadth than detail and is so ambitious that Republicans greeted it with derision. Its legislative prospects are bleak in the foreseeable future; House Speaker Nancy Pelosi, D-Calif., has no plan to bring the resolution in its current form to the floor for a vote, according to a Democratic leadership aide with direct knowledge of her plans.

But as a blueprint for liberal ambition, it was breathtaking. It includes a 10-year commitment to convert “100 percent of the power demand in the United States” to “clean, renewable and zero-emission energy sources”; to upgrade “all existing buildings” to meet energy efficiency requirements; and to expand high-speed rail so broadly that most air travel would be rendered obsolete.

The initiative, introduced as nonbinding resolutions in the House and Senate, is tethered to an infrastructure program that its authors say could create millions of new “green jobs,” while guaranteeing health care, “a family-sustaining wage, adequate family and medical leave, paid vacations and retirement security” to every American.

“Climate change and our environmental challenges are the biggest existential threats to our way of life,” Ocasio-Cortez said Thursday. “We must be as ambitious and innovative in our solutions as possible.

Markey added, “We will save all of creation by engaging in massive job creation.”

The resolution, modeled on President Franklin D. Roosevelt’s New Deal in the 1930s, will not move in its current form, but some ideas could advance as part of more modest legislation to address the climate crisis. Ocasio-Cortez, the chief architect of the deal, is not part of a new special select committee on climate change. She and Pelosi’s office said she had been offered a seat on the committee but she declined it, an assertion confirmed by an aide to Pelosi.

“Frankly, I haven’t seen it,” the speaker told reporters when asked about the Green New Deal proposal during her weekly media availability at the Capitol on Thursday. “But I do know it is enthusiastic, and we welcome all the enthusiasm that is out there.”

Pelosi is likely mindful of her own past mistakes. A decade ago, she pushed the last major climate change measure hard, an ambitious bill to cap emissions of climate-warming pollution, then allow industries to trade emissions credits on a pollution credit market. Through force of will, she got the cap-and-trade measure through the House, only to see it die in the Senate without a vote. The next year, Democrats were swept from power, in part because of that vote and the Republicans’ framing of it as a stealth tax hike.

In that Congress, she had a Democratic Senate and a Democratic president, Barack Obama. This time, she has a president who calls climate change a hoax and a Senate in the control of Mitch McConnell, a Republican majority leader from the coal state of Kentucky.

But on Thursday, she was also intent on letting her critics on the left know about her own past efforts, adding that she had made climate change the “flagship issue” of her first speakership.

Proponents of the Green New Deal insisted that Democrats were unified. Both Markey and Ocasio-Cortez praised Pelosi as a “leader” on climate change, and Ocasio-Cortez said she was not offended by Pelosi’s description of the Green New Deal in an interview with Politico on Wednesday as the “green dream, or whatever they call it.”

“I think it is a green dream,” Ocasio-Cortez said. “I will not allow our caucus to be divided by whatever narrative.”

Republicans seized on the proposal with relish, portraying the entire resolution as absurd.

“The socialist Democrats are off to a great start with the roll out of their ridiculous Green New Deal today!” said Bob Salera, spokesman for the National Republican Congressional Committee, the political arm of House Republicans, who called the idea “zany.”

The Republican National Committee derided it as “a socialist wish list.”

But Democratic candidates for the presidency did not shy away from it once details emerged. Sen. Kamala Harris, D-Calif., quickly sent out a fundraising appeal, declaring, “For too long, we have been governed by lawmakers who are beholden to Big Oil and Big Coal. They have refused to act on climate change. So it’s on us to speak the truth, rooted in science fact, not science fiction.”

Sens. Kirstin Gillibrand, D-N.Y., Cory Booker, D-N.J., and Bernie Sanders, I-Vt., also co-sponsored the measure, which has early support from about 60 House and Senate Democrats.

For all of the resolution's audacity, Ocasio-Cortez and Markey also steered clear of several thorny issues, and there were even signs of concessions to moderate Democrats and Republicans interested in working on clean energy issues.

For example, the resolution does not specify a date for eliminating planet-warming emissions, instead calling for the elimination of fossil fuels from major economic sectors “as much as technologically feasible.” It also avoids denouncing specific types of clean energy alternatives, specifically nuclear power, which in the past has come under fire from climate change activists despite being a zero-carbon form of energy. An early version of the resolution called for phasing out nuclear energy within a decade.

The resolution also sidesteps any discussion of carbon capture and storage technology, which Green New Deal supporters had previously criticized on the grounds that it would enable the continued use of fossil fuels.

Markey said the resolution is purposefully “silent on individual technologies.”

Instead the resolution calls for generating all electricity through renewable sources like wind and solar within 10 years, eliminating greenhouse emissions in manufacturing and forestry “as much as is technologically feasible,” and re-engineering cars and trucks to end climate pollution.

The measure also includes social justice goals not usually attached to anti-pollution plans, like eradicating poverty by creating high-paid jobs.

But the resolution goes far beyond that, touching on themes that are animating a rising left but that rarely reach the halls of Congress. It aims to “promote justice and equity by stopping current, preventing future, and repairing historic oppression of indigenous peoples, communities of color, migrant communities, deindustrialized communities, depopulated rural communities, the poor, low-income workers, women, the elderly, the unhoused, people with disabilities, and youth.”

Markey, who co-sponsored the failed cap-and-trade measure with former Rep. Henry Waxman, D-Calif., said he thought the public was far more ready than in 2009 to support climate change legislation. A decade ago, he said, fossil-fuel backed interest groups poured money into convincing the public that climate change was not real.

“The green generation has risen up and they are saying we want this issue solved,” Markey said. “We now have the troops, we now have the money, and we’re ready to fight.”

This article originally appeared in The New York Times.