Standards can have a big effect. The Obama policies, combined with technological advances in solar and wind power, have helped reduce coal’s share of the power sector to 20 percent, from almost 50 percent in 2010. Thirty states have created their own energy standards, including California, New York, Arizona and Colorado, which has also helped. In some cases, the state-based policies are the result of a referendum.
That’s a sign that these standards tend to be more popular than energy taxes: Most Americans support pollution reductions. Opponents still portray them as tax increases, as they no doubt will during the Biden administration. “The oil industry is always going to be arguing that no matter what you do, it’s a price on carbon,” as Mr. Markey told me. But it’s easier for climate advocates to win that argument.
In some cases, Mr. Biden may use the threat of regulation to negotiate with industry. Automakers seem open to making a deal. When Mr. Trump tried to free them from Obama-era restrictions, some balked. Many auto executives understand that clean-energy cars are the future. They would rather get working on the transition, rather than having to maintain two different product lines — gas-guzzling vehicles in some places (like red states) and more fuel-efficient cars elsewhere (like California and Europe).
With a Republican Senate, the Biden climate agenda will consist of dozens of smaller pieces, rather than one sweeping piece of legislation. The Agriculture Department will create incentives for farms to emit less carbon, and the Energy Department will do the same for buildings. On Capitol Hill, the administration will try to add some clean-energy subsidies to legislation on virus relief and infrastructure.
Foreign policy will also be geared toward persuading other countries to emit less. China, in particular, has shown more willingness to listen to American requests on climate change than on other big subjects, like human rights and intellectual property.
Will this be enough to avoid the worst consequences? It is impossible to know. Our chances would certainly be better if Congress were able to pass major legislation.
“We have to use every tool in the toolbox on climate action, before it is too late,” Ms. Castor said. Ms. McCarthy added: “We are way past the time when we should be looking incrementally instead of very aggressively.”