Imagine jumping into a self-driving car with two other commuters in the morning, the electric engine humming as you drive through smooth traffic and past empty parking lots, before arriving at work and paying a couple of dollars for the ride.

The auto industry and researchers say this utopian view of transportation is on the horizon, and it could cut nearly all of the carbon emissions from the transportation sector. Maybe.

A new report today finds that layering the three vehicle technologies—autonomous, electric and shared—on top of one another could cut carbon emissions 80 percent by 2050 worldwide from a business-as-usual scenario.

Researchers at the Institute for Transportation and Development Policy and the University of California, Davis, modeled how each new development might change carbon emissions around the world.

“It’s becoming increasingly clear that all three of these possible revolutions are reaching maturity,” said Lewis Fulton, a co-director at the Institute of Transportation Studies at UC Davis and lead author of the report. “It’s time for all of us, whether we’re researchers or policymakers or the general public, to think more deeply about where these things seem to be going. In 10 years, it may be too late to change the trajectory. It’s the time now to figure out which trajectory is the best.”

While some transportation researchers have suggested autonomous cars could cut emissions by boosting driver efficiency, others, including Fulton and his colleagues, project that energy use and carbon emissions would increase over a business-as-usual scenario because more people will travel farther.

Emissions reduction comes only when the vehicles are electrified and plugging into an increasingly cleaner grid.

“We have to stop thinking that self-driving cars will automatically be sustainable,” Fulton said. “We need policies to make sure we steer this towards electric and efficient.”

The most advanced scenario in the report requires people to change their behavior, using substantially more ride sharing, public transport, cycling and walking. That would cut car travel by more than half in 2050, and the number of cars by nearly three-quarters.

Worldwide, that combination would generate 0.7 gigaton of carbon emissions annually by midcentury, as opposed to 1.7 gigatons in the second one and 4.6 gigatons in a business-as-usual scenario.

In the United States, transportation has surpassed the electricity sector as the top source of greenhouse gas emissions, at around 30 percent. The most utopian scenario could cut that by nearly 90 percent in 2050, or the equivalent to shutting down 172 coal-fired power plants in a year.

The changes could cut the cost of buying, fueling and operating the cars by more than 40 percent.

Fulton also recognized that upending the transportation sector would require overcoming the attachment many people have to their individual cars, saying that government would have to play a “major role.”

Incorporating more ride sharing and public transit was the only scenario that matched with a pathway to keep global warming under 2 degrees Celsius.

Reprinted from Climatewire with permission from E&E News. E&E provides daily coverage of essential energy and environmental news at