Hillary Clinton has vowed to slash U.S. oil consumption in the next decade as part of an overall plan to shift the country to clean, renewable energy, but experts say her goal is probably impossible.
The target — to cut U.S. oil consumption by a third by 2027 — is an example of Clinton's hard line on fossil fuels during the Democratic primary and the general election. But some of her tough talk leaves her considerable wiggle room and contrasts with her record while serving as America's top diplomat.
That record includes a program to promote natural gas development overseas through the use of hydraulic fracturing, a method of unlocking oil and gas from rock formations by pummeling them with water, minerals and chemicals. "Fracking" is widely opposed by environmentalists.
CNBC asked experts to assess Clinton's energy proposals after carrying out a similar evaluation of Donald Trump's claims that he would boost economic growth by rolling back regulations and expanding drilling.
Clinton says she would extend standards for vehicle fuel efficiency, methane emissions, building codes and appliance standards that President Barack Obama implemented or supported, according to a campaign spokesperson. Clinton supports Obama initiatives like the Clean Power Plan and new Environmental Protection Agency regulations on oil and gas drilling, which have drawn the ire of the energy industry and legal challenges. She also backs raising the royalty rates for drilling on federal land and cutting tax breaks for oil and gas firms, and she opposes offshore fossil fuel development in the Arctic and Atlantic oceans.
That said, while the Obama administration has ratcheted up regulations and limited drilling on federal land, it also presided over a 75 percent increase in U.S. oil output in its first seven years. The boom continued until a sharp oil price downturn forced American producers to cut back output.
Clinton seeks to generate 33 percent of U.S. energy capacity from renewable sources, enough to power every home in America, and would launch a $60 billion program to help states and cities make buildings more efficient.
But Clinton's goal is considerably more aggressive than the International Energy Agency's view on the medium-term trend outlined earlier this year in an annual report. It sees U.S. consumption dropping by just a quarter by 2040.
It would also represent a remarkable acceleration of the current trend. In the last 10 years, crude oil and petroleum products used by American business and citizens fell just 6.7 percent — or just one-fifth of the pace Clinton is projecting.
The Clinton campaign did not provide a response in time for this report.
At present, it would be difficult to see U.S. oil consumption falling that rapidly, and the campaign promise should be taken more as a sign of Clinton's dedication to emissions than as an actually achievable target, said Antoine Halff, former chief oil analyst at the International Energy Agency.
"As an ambition, it's legitimate. As a projection, it's aspirational," he told CNBC. "It's not necessarily to be taken at face value as a forecast."
The Clinton campaign has not detailed a plan for how it would achieve its goal. It has proposed offering grants to phase out home heating fuel, supporting electric vehicle infrastructure and more quickly deploying natural gas-fueled trucks, buses, trains and ships.
Halff is now working with researchers at Columbia's Center on Global Energy Policy to build models that can forecast how electric vehicles, ride-sharing and a host of other factors could affect energy markets in the future.
Motor gasoline accounted for nearly half of America's total petroleum product consumption of 19.4 million barrels a day last year, so fuel efficiency and electric vehicle adoption would have to play a significant role in driving down oil demand on a large scale.
In Halff's view, the research necessary to back a target as ambitious as Clinton's remains incomplete.
"I don't think anybody has clear visibility on how quickly and on what scale those changes could affect the market," he said.
Peter Saundry, chief scientist at the National Council for Science and the Environment, says he too believes Clinton's oil consumption goal would be difficult to accomplish.
One reason: New, advanced biofuels have failed to deliver on early expectations, confounding attempts to increase the ratio of products like ethanol that are mixed into gasoline under the EPA's national Renewable Fuel Standard Program, Saundry said.
At the same time, oil prices have remained persistently low following a price collapse in 2014, raising demand for SUVs and pick-up trucks and emboldening the auto industry to push back on fuel standards, he said.
"That doesn't help achieve those standards, because there's a profit motivation to sell those heavier gas guzzling vehicles," Saundry told CNBC.
Clinton could opt to take an inflexible stance on fuel standards and even lobby for a gasoline tax, but she would have limited ability as president to ramp up adoption of electric vehicles, in Saundry's view. Their success depends on the continued decline in the cost of vehicle batteries as technology improves, he explained.
Essentially, it would take a perfect storm to reach her goal, and such a combination is not likely to brew anytime soon.
The energy industry has prepared for a decline in oil consumption as the developed world weans itself off hydrocarbons, but the prospect of a rapid decline on the scale that Clinton is promising would be "a different story," Columbia's Halff said.
"It could lead to a very bumpy adjustment period," he said, though he cautioned that any such decline is hypothetical, and so projecting its impact is dicey.
Trump energy adviser and fracking mogul Harold Hamm has claimed Clinton "would eliminate fossil fuel development in America," but that claim is likely an overstatement.
For one, the State Department under Clinton launched the Bureau of Resource Management, which sought to export shale drilling capabilities in order to reduce U.S. allies' reliance on coal and natural gas from Russia.
Clinton took a harder stance on fracking while locked in a tough primary with Sen. Bernie Sanders, who backs a national ban on the drilling method, but a close examination of her statements shows she has left herself considerable leeway to allow fracking to operate largely as it does already.
During a primary debate in March, Clinton outlined three conditions under which she does not support fracking: when a locality or state opposes it, when the chemicals used in fracking fluids are not subject to disclosure and when it leads to the release of methane or contaminates water sources.
Clinton said by the time those conditions are addressed, she does not think "there will be many places in America where fracking will continue to take place." But in fact, there are few places under federal jurisdiction where those conditions exist and have not already been addressed by the Obama administration.
Among the four states that ban hydraulic fracturing, only New York has significant natural gas reserves. And while a number of cities and counties have put up challenges to fracking, the oil and gas industry is hardly under siege.
For example, the Colorado Supreme Court this year ruled that state fracking regulations supersede local measures, in the process overturning a moratorium on fracking enforced by the cities of Fort Collins and Longmont. In August, efforts to limit drilling in the state failed to make the ballot.
As for disclosure of fracking fluids, that's currently regulated by states. The Clinton campaign told CNBC it supports passing national rules requiring the disclosure of fracking fluids, something for which groups including the National Resources Defense Council have long advocated.
Current state rules include loopholes such as trade secret exemptions meant to protect drillers' formulas for fracking fluids.
That leaves the issue of water contamination and methane pollution. The draft summary of a 2015 EPA study found it was possible for fracking to contaminate water, but turned up no evidence fracking has "led to widespread, systemic impacts on drinking water resources in the United States."
The methane issue could be trickier, since it's common for drillers to flare off the greenhouse gas as part of normal operations. However, the United States is already on track to tackle those emissions.
The Environmental Protection Agency has issued new rules for regulating the release of methane from new or modified well equipment. Industry watchers fully expect the EPA to apply these rules to existing wells, and indeed, the agency's new rules came with a request for information from drillers on how the measures could be applied retroactively.