Still, Shapiro and others agree that government policy can enormously influence the pace of the transition from fossil fuels. In a recent paper, he and several colleagues calculated that repealing the IRA’s $7,500 tax credit for purchasing a new electric vehicle, as Trump has pledged to do, would reduce the sales of new EVs by 27%. Domestically assembled EVs would suffer an even greater 37% decline, they forecast, because of the law’s provisions benefiting vehicles built in the US.

That’s only one example of how the energy decisions made over the next four years could reverberate for decades. The US reliance on the fossil fuels driving climate change has been declining for years, but only at a modest pace. In 2000, fossil fuels provided 88% of the nation’s energy, according to the Energy Information Administration; in 2023, the latest year for which figures are available, that number was 82.5%.

Biden’s agendawould unquestionably accelerate that change: The Rhodium Group has projected that if current policies remain in place, carbon-free sources within the next decade would provide three-fourths of the nation’s electricity, while electric vehicles would comprise two-thirds to three-fourths of new car sales. In all, the group forecasts that under Biden’s policies, fossil fuels over the next decade would fall to anywhere from 75% to as little as 58% of the nation’s energy mix, according to Ben King, an associate director of Rhodium’s climate and energy practice. That’s a much faster pace of decline than in the past quarter-century.

Even in that world, King notes, oil and gas producers are hardly facing an existential threat to their business in any medium-term time frame. “It is a more gradual energy transition than people initially think,” King said.

Yet interrupting that transition by repealing the federal policies benefiting clean energy remains a dangerous gamble. The result could be a vicious downward cycle: less investment in lower-carbon energy alternatives, which means less production, which yields fewer gains from advances in technology and manufacturing efficiency, which means less adoption, which translates into further reductions in clean energy investment and more years with fossil fuels entrenched as the nation’s predominant energy source.

All of that, in turn, would ensure years of greater carbon emissions – with ominous implications for extreme weather and other manifestations of climate change.

“If the world adopts EVs in 2060 rather than 2020, it makes a giant difference for the planet because there is 40 years of burning gasoline rather than using a cleaner grid,” Shapiro said. “So the pace of adoption matters even if we end up at the same place in the end.”

The brown blockade in Washington can’t entirely stop the shift from fossil fuels to a low-carbon energy future – but, as the first months of Trump’s second term may quickly demonstrate, it can significantly slow the change, and raise the cost of delay.