Yet such scenarios would involve an extraordinary push. Dr. Jacobson’s plans would require, among many other actions, that 156,000 wind turbines be built off American coasts in the next 35 years, and twice as many on land. In 20 years of effort, European countries have managed to build about 3,000 offshore turbines.

In an interview, Dr. Jacobson cited a scientific paper that calculated the oil and gas industry has been building 50,000 new wells a year in North America since 2000. Each of those, he said, is as complicated as erecting a wind turbine, and building tens of thousands of turbines a year would be well within the nation’s industrial capability.

“We think it’s technically and economically feasible,” Dr. Jacobson said. “It ultimately does come down to political will. If people don’t want to do it, it’s not going to happen by itself.”

Dr. Jacobson has often cited the United States’ mobilization during World War II as an example of what can be done by a determined society. But to some other experts, that very argument speaks to the political and economic impracticality of his plans.

“I just don’t see a World War II-style mobilization happening for anything other than a world war,” said Jesse Jenkins, an energy analyst at the Massachusetts Institute of Technology. “We’re not going to do that. So the question is, what are we going to do?”

The scenarios laid out by the Deep Decarbonization Pathways Project echo Dr. Jacobson’s plans to a degree, in that they call for substantial amounts of renewable power. But these scenarios also suggest that the energy transition would be easier and cheaper with additional technology options, including some that are disliked by the environmental movement.

For instance, in some countries with growing power demands, like China, the research found that nuclear power would be essential for staying within a strict emissions budget. Mr. Jenkins said that new nuclear plants would also be needed in some American states that had few other options.