WASHINGTON — Senator Bernie Sanders’s $16 trillion vision for arresting global warming would put the government in charge of the power sector and promise that, by 2030, the country’s electricity and transportation systems would run entirely on wind, solar, hydropower or geothermal energy, with the fossil fuel industry footing much of the bill much as Mexico was to pay for the border wall.
Climate scientists and energy economists say the plan is technically impractical, politically unfeasible, and possibly ineffective.
Yet the criticism does not appear to bother many of the young voters who will have an important role in selecting a Democratic presidential candidate, and who overwhelmingly place climate change at the top of their priority lists, according to polls.
“He has some really great ideas that may not be passed, but it’s definitely stuff that needs to be brought up,” said Chandler Condon, a 25-year-old supporter who traveled from Denver to Des Moines last week for a climate rally with Mr. Sanders.
“People saying that it’s too radical, it’s like, well, we need that radical change,” she said.
David Victor, a professor of international relations at the University of California San Diego and a climate adviser to Pete Buttigieg, the mayor of South Bend, Ind., called that “the big challenge for serious policy in the Democratic Party.”
“The progressive wing wants radical change, and climate change is one of those areas where this has really been the most palpable,” he said. “The Sanders plan claims to deliver radical change, but it can’t work in the real world.”
Mr. Sanders is not a newcomer to the climate issue; he has spent decades fighting, largely unsuccessfully, for ambitious legislation to increase clean energy, reduce carbon emissions, and end fossil fuel subsidies. He distinguished himself in the 2016 Democratic primaries by calling for a tax on carbon emissions and declaring global warming a national emergency.
This time, he faces a crowded field of candidates vying to outdo one another on global warming. But Mr. Sanders seems to have cemented his status as the climate candidate with the most expensive plan, an early embrace of the Green New Deal and a rally last weekend with Representative Alexandria Ocasio-Cortez, the Green New Deal’s most prominent champion.
On Thursday Mr. Sanders and Ms. Ocasio-Cortez introduced a 10-year, $180 billion “Green New Deal” for public housing, the first major effort to bring the vision of grappling with both climate change and income inequality into legislation. The bill would provide for retrofitting one million units of federally-owned housing.
Joshua Orton, a spokesman for Mr. Sanders, said critics were failing to see that momentum is already moving toward dramatic action. The price of renewable energy is falling. Technology is improving. And the public is increasingly demanding action.
“Many critics are working from a set of pessimistic, establishment political assumptions that will, frankly, result in disaster,” he said. “The current model is unsustainable, and it’s wrong to assume that the plan accepts the status quo in terms of the costs and technology of today.”
But to most climate change experts, Mr. Sanders’s promise to reduce American emissions by 71 percent in a decade and to fully convert to renewable energy by 2050 may win high marks for ambition, but major elements of his plan to get there are implausible.
The heart of Mr. Sanders’s plan, a government-run effort to build, manage and distribute renewable energy on a vast scale, would cost more than $2 trillion if it could pass muster in Congress and, several economists said, it might not even curb emissions.
His rejection of nuclear energy and technology to capture carbon emissions would make his carbon-reduction targets much harder. His notion of paying for renewable energy by “making the fossil fuel industry pay for their pollution” is vague. And, economists said, his climate plan fails to consider his larger agenda, such as the new infrastructure projects in his economic plan that would create a burst of new emissions. High-speed rail, wind turbines and mass transit need steel and concrete, the production of which requires energy.
“He’s trying to set a marker in terms of the pace and scale of spending that he’s proposing,” said Jesse Jenkins, an energy systems engineer and assistant professor at Princeton University. But, he added, “I don’t think that represents a very nuanced understanding of the set of challenges that we face.”
Paul Hawken, the author of Project Drawdown, which analyzes solutions to global warming, said, “His sense of urgency in here is correct, in my opinion. But you can take that sense of urgency and make it more effective.”
Joel Payne, a Democratic strategist, said Mr. Sanders was more focused on signaling his ambitions to the party’s liberal wing than sweating policy details.
“People who care about these issues want a warrior,” Mr. Payne said. “Whether or not the battle plans they draw up exactly check out is kind of beside the point.”
The foundation of Mr. Sanders’s climate change plan is using the federal government to build and generate renewable energy, and sell it to publicly owned distribution systems, with preferential prices for utilities that pledge to break themselves of fossil fuels. The “greed” of profit-driven electric utilities, he has argued, has made them underinvest in the electric grid while clinging to dirty energy.
Mr. Sander’s plan envisions expanding the four existing federal agencies that market electric power, known as federal Power Marketing Administrations, as well as the Tennessee Valley Authority, a government-owned corporation. He would create a fifth such agency that would spend $1.52 trillion on developing renewable energy and another $852 billion on technology like advanced batteries to store energy for days when the sun does not shine or the wind does not blow.
Energy experts say the problems are multifold. Congress would have to create and fund these new entities, a heavy lift even with a Congress in Democratic control.
Moreover, pressure from Washington would not necessarily affect utilities’ likelihood of adopting clean energy. Municipal power boards reflect their communities, so while liberal towns might demand greater levels of renewable energy, rural cooperatives in conservative states quite likely would not.
“I just don’t see that getting off the ground,” said Severin Borenstein, a professor at the Haas School of Business of the University of California, Berkeley.
Not everyone sees doom in Mr. Sander’s nationalization of the power sector. Daniel Kammen, an energy expert at the University of California, Berkeley, called it “audacious but doable.”
Noah Kaufman, a researcher at Columbia University who worked on climate change in the Obama administration’s White House Council on Environmental Quality, said Mr. Sanders’s plan recognized that the planet could not afford to wait for market forces to find solutions.
“Climate change presents risks that are big and that are scary, and for that reason it’s being talked about like a crisis,” he said. “He’s proposing policies that match that rhetoric.”
Other analysts criticized Mr. Sanders’s rejection of nuclear energy and technology to capture and store carbon emissions. His plan calls both of those “false solutions” to climate change and calls for a moratorium on the renewal of nuclear power plant licenses.
Yet nuclear power currently accounts for 20 percent of the nation’s energy mix and more than half of its carbon-free power. Allowing aging plants to close would likely mean that natural gas, a fossil fuel, would fill the void and emissions would rise.
“The last thing you want to do is be righteous about how you feel about nuclear,” Mr. Hawken said.
Michael Oppenheimer, a professor of geoscience and international affairs at Princeton University, said Mr. Sanders’s plan did not appear to take political realities into account. He also said he was disappointed that Mr. Sanders no longer supported a carbon tax, a position he embraced in 2016. Economists say a fee on the burning of fossil fuels is the most efficient way to drive down global warming, but Mr. Sanders says that would not work quickly enough.
Still, Mr. Oppenheimer said, Mr. Sanders wins points on vision.
“When I talk about these issues I have to be realistic, but that’s why I don’t run for president,” he said. “You need more than that in the political arena. You can’t drain these issues of their lifeblood and turn them into numbers and realistic deadlines and expect people to get engaged about it.”
Zina Precht-Rodriguez, 23, an activist with the Sunrise Movement, a youth-led climate change group, traveled from Philadelphia to speak at the Des Moines rally last week. She said it’s important to have faith.
“It’s not necessarily proved that it’s impossible because it’s never been tried,” she said.