Efforts to drastically slash automobile emissions and fuel use within 40 years don't stand a chance without subsidies, technology improvements and more stringent government standards, according to a report by a US panel of experts released Monday.
Congress in 2010 directed the National Research Council to assess the feasibility of reducing both gasoline use and greenhouse gas emissions in cars and light trucks by 80 per cent by 2050. The council concluded that goal would be "extremely challenging."
Even hitting an intermediate target – cutting fuel use in half by 2030 – would be "very difficult," the council reported.
"Vehicles must become dramatically more efficient, regardless of how they are powered," said Douglas M Chapin, an engineer who chaired the committee that wrote the report, in a statement.
In addition, alternative fuels must be readily available, cost-effective and produced with low emissions of greenhouse gases, he said.
"Such a transition will be costly and require several decades.... On its own the market would not make this transition," Chapin, a principal at a Virginia-based consulting company, MPR Associates, added.
The panel was made up of 19 engineers and other auto and energy experts from academia, industry, private consulting firms and elsewhere.
The panel identified four ways to reduce oil use and emissions: More efficient gas-powered engines, and vehicles that use biofuels, electricity or hydrogen. Natural gas vehicles were considered, but their greenhouse gas emissions are too high for the 2050 goal.
There is no "silver bullet," Chapin said. With technologies uncertain, the panel felt the best approach would be to promote a portfolio of vehicle and fuel research and development.
The report made clear the costs of transitioning away from fossil fuels is high. But it also noted the economic benefits of such a transition outweigh the costs.
Still, the transition to alternative vehicles will not be cheap. By 2050, the authors project the manufacturing of hybrid electric and fuel cell vehicles will be cheaper than conventional vehicles, but battery electric and plug-in electric hybrids will still be more expensive.
For consumers, alternative vehicles will still probably be several thousand dollars more than what conventional vehicles cost now, the authors note.
Daniel Sperling, director of the Institute of Transportation Studies at the University of California, Davis, said he was more optimistic than the panel about the move away from fossil fuels.
"Given the strong commitment of the auto industry to efficiency and the strong vehicle policies already in place, one can plausibly argue that the industry is on a trajectory to an 80 per cent reduction in 2050," he said in an e-mail.
Cars and light trucks that use gasoline account for about 17 per cent of total US greenhouse gas emissions, according to the EPA.
Under today's federal standards, average vehicle fuel efficiency is set to rise to 54.5 mpg for cars and small trucks by 2025. The authors didn't say what the final number should be, but they noted it would need a "steady increase."
The Union of Concerned Scientists endorsed the report's "no silver bullet" conclusion.
"What we really need is silver buckshot: A suite of policy and technology options that will cut oil use while protecting consumers and strengthening our economy," said Michelle Robinson, director of the group's clean vehicles program, in a statement.
The alternative vehicle choices are there now, said Gloria Bergquist, vice president of the Alliance of Automobile Manufacturers, an industry trade association. But the cars are only "one leg of the three-legged stool," she said. The country also needs widely available energy to power alternative vehicles – such as clean diesel, electric charging stations.
"And we need consumers to buy the new vehicles in large numbers," she said.
That's not happening yet: After a dozen years on the market, gasoline-electric hybrids – like the Toyota Prius or Chevrolet Volt – account for no more than three percent of total vehicle sales, she said. The best-selling pickup truck on the market outsells all electric vehicles combined.
Still, state and regional efforts are pushing the industry closer to the congressional goal. California, for instance, requires that auto manufacturers sell 1.4 million zero-electric vehicles, or ZEVs – such as battery-powered electric vehicles – by 2025. Nine other states are considering following California's lead, though auto manufacturers have warned they cannot hit that target.