WASHINGTON — Democratic candidates promised unprecedented new action on climate change on Wednesday night in the first prime-time televised forum devoted to the issue in a presidential campaign, vowing to undo the Trump administration’s environmental policies, spend trillions of dollars to promote renewable energy and force companies to pay new taxes or fees.
In perhaps the most significant development of the night, more than half of the 10 candidates at the forum openly embraced the controversial idea of putting a tax or fee on carbon dioxide pollution, the one policy that most environmental economists agree is the most effective way to cut emissions — but also one that has drawn intense political opposition. Around the country and the world, opponents have attacked it as an “energy tax” that could raise fuel costs, and it has been considered politically toxic in Washington for nearly a decade.
Nearly all of the candidates have called for rejoining the Paris climate change agreement, which commits nearly every country on earth to lowering emissions, and for implementing policies that will put the nation on track to a carbon-neutral economy by 2050.
While the candidates appeared in back-to-back interviews, it was a former presidential hopeful, Gov. Jay Inslee of Washington, who dominated the event in an unusual way. He made climate change the singular focus of his campaign before dropping out of the race last month, only to see several of the current candidates echo his ambitious proposals in their climate plans and at Wednesday’s forum on CNN.
“You may remember Gov. Jay Inslee said, ‘Let’s get tough on this,’” said Senator Elizabeth Warren of Massachusetts, as she laid out a new plan that she said had been influenced by her former rival. In addition to proposing $3 trillion in spending on environmental initiatives, Ms. Warren also responded “Yes!” when asked by a moderator, Chris Cuomo, if she would support a carbon tax — a measure she had not spelled out in her official policy proposal.
Senator Bernie Sanders of Vermont, who has not explicitly taken up Mr. Inslee’s ideas, said, “We are proposing the largest, most comprehensive program ever presented by any candidate in the history of the United States.” Mr. Sanders has sought to win over the liberal wing of the Democratic Party with a plan that takes its name from the Green New Deal and has the biggest price tag of all the candidates’ proposals — $16.3 trillion over 15 years. He is one of the few candidates who has not called for a carbon tax, however.
Former Vice President Joseph R. Biden Jr., whose team called Mr. Inslee’s staff earlier this week to set up a time to talk about policy ideas, and whose official policy plan does call for a carbon price, sought to position himself as a seasoned international leader on an issue that is fundamentally global in scope. While the United States is the world’s largest historic polluter of greenhouse gases, it today produces about 15 percent of total global emissions, and experts have said it is impossible to solve climate change without international curbs on emissions.
In the Group of 7, “I know almost every one of those world leaders,” Mr. Biden said, adding, “If I was present today, I would be — there would be no empty chair,” referring to a recent gathering at which Mr. Trump skipped a meeting on climate change.
“I would be talking to the president of Brazil and saying, ‘Enough is enough,’” Mr. Biden said, evidently referring to the deforestation policies of Jair Bolsonaro, which environmentalists say have contributed to the wildfires now destroying the Amazon rainforest.
Senator Kamala Harris of California, who on Wednesday morning released a plan to put a price on carbon, used the debate stage to take a page straight out of Mr. Inslee’s playbook. She pledged to enact aggressive environmental policies that just a few years ago were voiced only by the most left-wing candidates — calling for outright bans on hydraulic fracturing, or fracking, for oil and gas, and on offshore oil and gas drilling.
“This is an existential threat to who we are,” she said of climate change.
Mayor Pete Buttigieg of South Bend, Ind., who also released his climate plan on Wednesday, took the stage declaring his support for a carbon tax, adding, “I know that you’re not supposed use the T-word in politics.”
Policy analysts said they were struck by the sudden widespread embrace of carbon pricing, while Republicans said they welcomed it.
“Economists widely agree that an economywide price on carbon is the single most important policy for tackling climate change,” Richard Newell, president of Resources for the Future, a Washington research organization, said in an email. But he added: “It wasn’t clear that long ago whether supporters of a Green New Deal would view a price on carbon as being an important, or even acceptable, approach to achieving its principles. That test has clearly come down in favor of a carbon price within the Democratic primary process.”
The broad support for putting a price or tax on carbon dioxide is a remarkable change since the 2016 campaign, when Hillary Clinton steered clear of embracing a price on carbon pollution, for fear that it would be attacked as an energy tax.
“It’s a good policy to adopt if you want to lose an election,” said Myron Ebell, who heads the energy program at the Competitive Enterprise Institute, an industry-funded research organization, and who led the Trump administration’s transition at the Environmental Protection Agency.
The town hall-style forum on CNN was a response to intense interest in climate change among many Democrats. The event followed a decision by the Democratic National Committee not to sanction a debate devoted to the subject, frustrating activists and some candidates.
And it came as the National Hurricane Center warned that Hurricane Dorian, which has caused widespread devastation in the Bahamas, could cause life-threatening storm surge along most of the southeast Atlantic coast. Scientific research has shown that climate change has contributed to the worsening of hurricane impacts, by causing stronger, slower-moving hurricanes with larger storm surges.
A prime-time discussion about climate change was “20 years overdue,” Mr. Inslee said in an interview on Wednesday, adding, “I think we should attack Donald Trump on his weakest point, which is the environment, and this will help us identify our strongest candidate.”
Jeff Nesbit, executive director of Climate Nexus, a group focused on communicating the climate threat, said the forum reflected pent-up demand by a portion of the Democratic base to see global warming discussed in depth. Voters want “more than a scant, few minutes from TV news stars moderating general debates who ask questions like ‘Can Miami be saved?’ or ‘So, what’s wrong with the Green New Deal?’” he said.
But the seven-hour-long format may have challenged viewers’ stamina and frustrated those seeking clear contrasts between the candidates.
The parade of far-reaching plans on display, ranging in cost from $1.7 trillion to $16.3 trillion, also elicited Republican attacks. President Trump and his allies, who have sought to roll back Obama-era limits on planet-warming emissions, have been attacking the Democratic field as “socialists.” On Wednesday, the administration rolled back rules on energy-saving light bulbs.
“The Democrats’ radical approach to energy is to eliminate the use of all fossil fuels, which would kill more than 10 million jobs and inflict economic catastrophe across the country,” said Tim Murtaugh, a spokesman for President Trump’s re-election campaign.
Read More About the Candidates’ Plans
Yet Democrats nonetheless appeared eager to demonstrate their willingness to attack the fossil fuel industry.
Ms. Harris’s pledge to ban fracking, the controversial method of extracting oil and gas used across the country, would be an aggressive new check on the fossil fuel industry, one that was never proposed by President Barack Obama or by Mrs. Clinton.
Mr. Biden has not pushed to ban fracking, but he has signed a pledge not to take money from fossil fuel interests. He appeared taken aback by an audience question about his plans to attend a fund-raiser on Thursday co-hosted by Andrew Goldman, a co-founder of Western LNG, a Houston-based energy company that extracts and exports natural gas.
“Well, I didn’t realize he does that,” said Mr. Biden. “I was told, if you look at the S.E.C. filings, he’s not listed as one of those executives.” He later added, “But if that turns out to be true, then I will not in any way accept his help.”
More on Biden and Goldman
Two other candidates who said they would support carbon pricing, Senator Amy Klobuchar of Minnesota and the former housing secretary Julián Castro, said they would not call for outright bans on fracking. But both said they supported limiting the use of natural gas. Mr. Castro, a former mayor of San Antonio, said that in that job, he supported fracking for natural gas as a “bridge fuel” designed to take the economy to cleaner forms of power.
“We’re now getting to the end of that bridge,” he said.
Amid the parade of sweeping environmental and spending proposals, two candidates — Ms. Harris and Mr. Sanders — acknowledged the largest problem in enacting them: pushing them through a Congress that has failed to enact climate change legislation even when both chambers are controlled by Democrats.
In order to push her proposals through Capitol Hill, Ms. Harris called for another signature proposal of Mr. Inslee’s: ending the Senate filibuster, a century-old legislative institution, in order to overcome Republican opposition and push through new climate change laws.
Mr. Obama also sought to enact a sweeping climate bill that would have effectively placed a tax on carbon pollution, but it failed even when both chambers of Congress were controlled by Democrats because it could not overcome the 60-vote threshold required by the Senate’s filibuster rule in order to advance a bill through the chamber.
Mr. Inslee has called for abolishing the Senate filibuster — a move that would transform the way laws are made in the United States. Most of the presidential candidates have avoided calling for such a move, but analysts say that without it, their bold climate change plans — especially their calls for lavish spending — will remain unrealized.
But abolishing the filibuster could also make laws vulnerable to quickly being undone by a new Senate majority, leading to an unstable whipsaw effect as laws are signed by one president and quickly undone by another.
Mr. Sanders acknowledged the political hurdle of pushing aggressive climate change policy through the Senate, but has not backed eliminating the filibuster. Instead, he proposed pushing climate change policy into must-pass budget legislation, which under Senate rules requires a simple 51-vote majority to pass.
Democrats used the same method to push through Mr. Obama’s sweeping 2010 health care reform bill.
More Coverage of Climate and the Campaign
Coral Davenport reported from Washington, and Trip Gabriel from New York. Lisa Friedman contributed reporting from New York.
Coral Davenport covers energy and environmental policy, with a focus on climate change, from the Washington bureau. She joined The Times in 2013 and previously worked at Congressional Quarterly, Politico and National Journal. @CoralMDavenport • Facebook