President-elect Joe Biden removes his face mask as he arrives to speak Nov. 2 at The Queen theater in Wilmington, Delaware. Credit: Carolyn Kaster / AP

WASHINGTON — Climate activists counting on President-elect Joe Biden to rapidly fulfill ambitious clean-energy promises may be in for disappointment.

Other priorities, including stimulating the coronavirus-ravaged U.S. economy, expanding health care and adjusting tax rates are likely to take precedence over sweeping legislative action to curtail greenhouse gas emissions and combat climate change. Biden also would face long odds in advancing any big climate bills through the Senate if Republicans maintain control.

Environmentalists could see early wins, as Biden swiftly rejoins the Paris climate accord and potentially blocks the Keystone XL oil pipeline on Day One. And a coronavirus stimulus bill that advances on Capitol Hill could make some investments in a green recovery, unleashing spending on electric vehicle charging infrastructure, grid modernization and energy efficiency.

Other initiatives — including imposing tough limits on greenhouse gas emissions from automobiles, power plants and oil wells — will move through a formal federal rulemaking process that’s slow by design.

“It’s going to take a little bit of time to craft rules” limiting fracking and fossil fuel development on federal land, RL Miller, chair of the California Democratic Party’s environmental caucus, said in a preelection interview. “I am looking forward to a fierce effort to undo the damage that Trump has done.”

Biden courted climate-minded voters with warnings including “global warming is an existential threat to humanity” and “we don’t have much time” to arrest it. Environmental activists said they want bold and rapid action in keeping with that urgency.

“He’s campaigned hard on climate change and he included it in the top three things he’s had to do,” Erich Pica, president of Friends of the Earth Action, said in an interview before Election Day. “We expect him to follow through.”

The Biden-Harris transition team emphasized plans to “immediately invest in engines of sustainable job creation” and fight “the persistent climate crisis” on its website Sunday.

There will be early tests of how far Biden will go to satisfy climate activists, including who he picks to fill his cabinet and key environmental posts and how much he fights for stimulus spending to be steered toward green priorities.

“Joe Biden has a climate mandate,” Sunrise Movement co-founder Varshini Prakash told reporters in a call Thursday. “We expect him to do everything in his power to act on climate change over the next weeks and months.”

Sweeping climate legislation is likely dead on arrival in the Senate if the chamber stays in the control of Republicans — a dynamic that could spur Biden to seek discrete congressional wins on smaller environmental priorities that could draw backing from red states.

“It won’t be as ambitious, no two ways about it, but we think there are opportunities to make progress,” particularly with pressure from the president and House of Representatives, said Gene Karpinski, president of the League of Conservation Voters.

Biden could rely on his decades of Senate experience to develop “negotiated compromises” with the chamber, observed Bracewell LLP’s Scott Segal. Biden’s background makes him uniquely equipped to help “create a middle path for legislation” in the Senate, Segal said.

Clean-energy advocates said potential areas of consensus include accelerating the buildout of high-voltage power lines to connect wind farms in the Midwest with urban areas and big investments in battery manufacturing that could lure Rust Belt support.

“We will have someone in the White House that has made a career of bringing people together, particularly across the aisle,” said Michael Brune, executive director of the Sierra Club. “I wouldn’t underestimate the ability of this new administration to identify legislation that will achieve multiple goals and meet some of the needs of Republican senators in their own districts.”

Sen. Joe Manchin, a Democrat from coal-rich West Virginia, urged caution.

“I would encourage all Democrats to be moderate” and “find the middle if you can,” Manchin said in a Sunday appearance on CBS’ “Face the Nation.”

“You’re not going to be able to govern from the extremes,” he said.

One complication could be preserving support from dueling wings of the Democratic Party. During his campaign, Biden courted workers and climate activists with promises his $2 trillion clean-energy plan would support millions of good-paying jobs building wind turbines, sustainable homes and electric vehicles.

“The Biden administration will have to manage a very tenuous coalition between progressive environmentalists and blue-collar union workers,” said Benjamin Salisbury, managing director of research at Height Capital Markets.

Biden is set to be a “pragmatic environmentalist,” and keep his focus on policies that drive demand away from fossil fuels and spur systemic change, Salisbury said.

Biden’s marquee proposal aims to make the U.S. electricity system carbon-free in just 15 years. That will require policies to force the shift as well as major technological advancements in power storage systems that can keep electricity moving long after the sun sets and wind slows — since emission-generating natural gas provides the essential backstop today.

Biden’s energy plan lays out epic changes in the U.S. energy mix, anchored by promises to install renewable energy infrastructure, get cleaner cars on the road and create zero-emission mass transit systems.

“They have much more demand for change than they can possibly supply,” observed energy consultant and former Trump adviser Mike McKenna. Progressive Democrats will “continue to act as if a narrow win, failing to take the Senate and slipping in the House gives the administration the ability to remake the entire nation.”

Facing a narrowly divided Senate, Biden will have to rely more heavily on advancing his priorities through federal regulation. For instance, tighter fuel economy limits could propel more electric vehicles. And a clampdown on power plant pollution could encourage utilities to shift away from natural gas as well as coal.

But Biden administration rules could face intense scrutiny in federal courts that have seen the addition of more than 200 judges appointed by President Donald Trump.