What the Stalled Build Back Better Bill Means for Climate, in One Chart

The fate of the imperiled Build Back Better bill in Congress will have major consequences for America’s ability to tackle climate change, researchers have estimated.

If the bill passes in something like its current form, with hundreds of billions of dollars for clean energy, the United States could get within striking distance of President Biden’s goal to cut the country’s planet-warming emissions in half by 2030. That could bolster global efforts to stave off a drastic rise in temperatures.

But if the bill dies, it could prove extremely difficult, if not impossible, for the United States to meet those aggressive climate targets. This week, Senator Joe Manchin III, a key Democratic swing vote, said he opposed the current version of the bill, putting legislative talks on the brink of collapse.

“There’s still a yawning gap between where we are today and where we need to be to hit President Biden’s climate targets,” said Jesse Jenkins, an energy systems engineer at Princeton University who has led an effort to model the effects of the Build Back Better bill on U.S. emissions. “Without either this bill or a climate bill that’s similar in scope, it’s really hard to see how those goals will be met.”

Earth has already warmed roughly 1.1 degrees Celsius (2 degrees Fahrenheit) over the past century, fueling ever more dangerous heat waves, floods, droughts and wildfires. Mr. Biden has set a goal of cutting U.S. greenhouse gas emissions at least 50 percent below 2005 levels by the end of this decade, which is roughly the pace that scientists say the whole world must follow to keep the Earth from warming beyond 1.5 degrees Celsius and minimize the risk of catastrophic impacts.

The United States is not yet on track to hit those emissions targets, even though clean energy technologies like wind turbines, solar panels and electric vehicles are getting cheaper and expanding rapidly. Various studies have estimated that the United States will only get about halfway to Mr. Biden’s climate goal under current policies.

The new $1 trillion bipartisan infrastructure law that Congress approved in November would only help slightly. It contains billions in new funding to research and develop low-carbon energy technologies, such as clean hydrogen fuels, advanced nuclear reactors and techniques to remove carbon dioxide from the atmosphere. It also contained $7.5 billion to build a national network of chargers for electric vehicles.

But apart from the vehicle chargers, many of those technologies could take years to develop and are unlikely to make a major dent in emissions over the next decade.

That’s where the Build Back Better bill is supposed to step in. The version of the $2 trillion bill that passed the House in November contains $555 billion in clean energy spending, including new tax credits for businesses that install wind, solar, geothermal, batteries and other clean energy technologies over the next decade. Buyers of electric vehicles would receive up to $12,500 in tax credits. And companies would receive financial incentives to keep open low-carbon nuclear plants in danger of closing prematurely or to capture emissions from industrial facilities and bury them underground before they can warm the planet.

“You can think of the two bills as complementary,” said Stephen Naimoli, who works on energy and climate issues at the Center for Strategic and International Studies. While the infrastructure law will help nurture the clean energy technologies of the future, the Build Back Better bill is designed to accelerate the use of technologies that are ready today, he said.

When Dr. Jenkins and his colleagues modeled the effects of the House version of the Build Back Better bill, they estimated that the United States would get most of the way to Mr. Biden’s 2030 goal, though the nation would still miss the deadline by about five years without additional action.

Wind and solar power would expand at roughly three to four times their current pace, the researchers estimated, while utilities would retire their remaining coal plants more quickly. Sales of electric vehicles would accelerate, leading to a decline in emissions from transportation. And companies would start installing carbon capture technology, burying millions of tons of carbon dioxide underground.

Dr. Jenkins cautioned that there is always some uncertainty involved in modeling. For instance, while the bill would give companies enormous financial incentive to build more wind and solar power, such projects could be hobbled by local opposition or a lack of new transmission lines. Still, most analysts agreed that the bill would amount to the single largest step ever taken by the United States to address climate change.

The big question, then, is whether the Senate will pass the bill, or make major changes. And that largely hinges on Mr. Manchin. With every Republican opposed to the bill in the evenly divided Senate, Democratic leaders need his vote to move the legislation forward.

Mr. Manchin, whose home state of West Virginia is a top producer of coal and natural gas, could seek further changes to the climate provisions in the House bill even if he does decide to sign on. For instance, he has objected to a fee on oil and gas producers that emit methane, a potent greenhouse gas. He has criticized the tax credits for electric vehicles, which he said should not be available to higher-income families. And he has said the House-passed bill would jeopardize the reliability of the electricity grid while increasing dependence on foreign supply chains.

If the climate bill dies altogether, the Biden administration will have fewer options for cutting emissions. The Environmental Protection Agency is working on regulations to reduce pollution from power plants, cars and trucks, but those efforts could face court challenges or be overturned by a new administration. And, while some states like California and New York continue to move forward with their own climate policies, those only cover a fraction of the country.

“Ultimately, we need to more than double the pace of emissions cuts this decade,” Dr. Jenkins said. “It’s an enormous lift, and you really need a national policy in place to do that.”