By John DeCicco
President Biden has proposed ambitious goals for curbing climate change and investing in a cleaner U.S. economy . One critical sector is transportation, which generates 28% of U.S. greenhouse gas emissions — more than either electric power production or industry.
Shifting from cars that run on gasoline and diesel to electric vehicles, or EVs, is a key strategy to address transportation’s contribution to global warming. Industry watchers expect big federal investments in charging stations and tax credits for electric cars. But as Biden’s Day One executive order on climate and the environment recognized, an even greater priority is making gasoline vehicles more fuel-efficient.
My research focuses on energy problems, including transportation and climate change . I believe though EVs are important, it’s emissions from the entire automobile fleet — meaning vehicles of all types and sizes — that ultimately matter for climate. Motorcars stay on the road for a long time , so failing to adequately reduce gasoline vehicle emissions this year burdens the atmosphere with excess carbon dioxide (CO2) for many years ahead.
Electric cars in context
The media spotlight on EVs can lend them outsize importance in discussions of the car-climate challenge. Tesla’s /zigman2/quotes/203558040/composite TSLA +3.02% leadership on electrification has boosted its stock to record levels . General Motors /zigman2/quotes/205226835/composite GM +0.54% has made the news with its announcements of new EVs in the making, and all major auto makers worldwide now have ambitious EV plans.
Even after accounting for emissions caused by generating electricity to power them, research shows that EVs clearly provide environmental benefits . They emit fewer pollutants that contribute to climate change and smog than gasoline-powered vehicles. And they avoid the environmental damage associated with drilling for oil, refining it into gasoline and transporting it to filling stations.
For these reasons, but especially because of EVs’ crucial role in cutting carbon, California aims to require new cars and light trucks sold in the state to be all-electric by 2035 . More than a dozen other states are adopting California’s clean-car strategies. Massachusetts recently announced its own plan to effectively ban sales of new gasoline-powered personal vehicles by 2035.
However, EVs are not yet close to having a measurable net impact on CO2 reduction. According to the U.S. Environmental Protection Agency’s automotive trends report , even as EVs have gained market share, carbon-cutting progress has ground to a halt .
Why? The surging popularity of highly fuel-consumptive pickups and SUVs. Indeed, EPA data show that to date, higher emissions from the market shift to larger, more powerful vehicles have swamped potential CO2 reductions from electric vehicles by a factor of five.
The role of clean-car standards
To appreciate this conundrum, it helps to understand how federal clean-car standards work. These regulations combine Corporate Average Fuel Economy (CAFE) standards with greenhouse gas emission standards . The two sets of rules are coordinated, because cars that get more miles per gallon have lower CO2 emission rates.
Both types of standards apply to auto makers on a fleetwide basis. Therefore, when auto makers increase their sales of EVs and other high-efficiency vehicles, they can sell a greater number of less fuel-efficient SUVs and pickup trucks while still meeting their fleet average greenhouse gas emission limits.
As a result, each additional EV sold does not yield a net CO2 reduction overall. In fact, because EVs get extra credit under the standards, electric car sales are now increasing fleet-average emissions to a level slightly higher than they would be without EVs in the mix.
Auto makers also exploit flexibility provisions built into the regulations. For example, a firm’s standard gets weaker when it makes its vehicles larger . On top of that, vehicles classified as light trucks — including four-wheel-drive and large SUVs as well as vans and pickups — are held to weaker standards than those classified as cars.
In spite of this regulatory flexibility, auto makers lobbied the Trump administration to weaken clean-car standards that had been developed under the Obama administration. In response, the Trump administration gutted the regulations in 2020. President Biden has directed federal agencies to revisit this issue , but for now, the weak existing standards mean that little carbon-cutting progress is on the horizon.
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