Electric vehicles are only one part of sustainable transit
They are improvements on combustion-powered cars—but we might need to rethink transportation to truly cut emissions.
Politicians and auto manufacturers alike are joining the electric vehicle caravan. At the end of March, the Biden Administration announced plans to invest $174 billion in the EV market, with some of the money going toward establishing a nationwide network of charging stations. California’s governor issued an executive order last year that all new vehicles sold in the state must have zero emissions by 2035. And automakers like GM have pledged to clean up their fleets in the near future.
Electrification of transportation is a crucial building block of a decarbonized future. Across their lifetime, EVs produce less greenhouse gas emissions than combustion-powered cars. But some experts warn that our tendency to focus on EVs in discussing transportation emissions is another example of our appetites for a quick techno-fix. “It’s attractive because it means you don’t have to change your behavior,” says Richard Watts, a professor of public policy at the University of Vermont.
Let’s be clear: swapping out gas and diesel engines for battery-powered ones would help in fighting climate change. Last year, a study in Nature Sustainability found driving an electric vehicle has fewer lifetime emissions—including greenhouse gases associated with production, use, and disposal—than a petrol-powered car across 95 percent of the world’s transportation systems. The only exceptions are places that mostly burn coal for energy, such as Poland. Even if the electricity powering EVs comes from natural gas, they still have the upper hand over gas-guzzlers because they are more energy efficient. EVs convert more than 77 percent of the energy used to power them into turning their wheels; in combustion, however, a lot of energy is lost—only 12 to 30 percent actually goes into propelling the vehicle.
How big that benefit is varies based on where you live, since the fuels that are powering your grid determine how carbon-intensive the electricity is. However, as many countries move to decarbonize, buying an EV now means your car will gradually become cleaner and cleaner.
Batteries are the dirtiest part of electric vehicles
But the climate advantage electric vehicles have is a result of their efficiency on the road. The manufacturing stage is another issue. Building an EV has a greater environmental impact than manufacturing a combustion car. During this stage, the energy and materials that go into making the EV result in greater greenhouse gas emissions. That’s largely thanks to the big battery packs that power EVs. “On average, producing a battery represents half of the emissions of producing an electric vehicle,” says Alexandre Milovanoff, a sustainability researcher at the University of Toronto. Just producing an EV battery pack itself can sometimes result in the same emissions as manufacturing an entire gas- or diesel-burning vehicle.
Each little cell that makes up the battery pack requires metals like lithium, cobalt, and nickel. Mining these materials can be destructive, polluting, and energy intensive. For example, refining nickel and cobalt from ore releases sulfur dioxide air pollution, says Qiang Dai, an energy systems analyst at Argonne National Laboratory. Then, turning these materials into battery components such as cathode powder, which helps convert stored energy into power for the car, also burns a lot of energy; for example, battery cells must be assembled in special “dry rooms” that require extensive humidity control.
Some of the components are also considered “critical minerals” by the US government, which means they are valuable to the economy but are sourced in a vulnerable supply chain. One example is cobalt, of which 70 percent is sourced from the Democratic Republic of Congo, where mining practices have been subject to concerns over human rights abuses.
The battery supply chain spans continents, making it inherently greenhouse gas intensive and hard to regulate. “Even for just one material, it could be mined in one country, and refined in another place, and then converted into, for example, active cathode powder in another country,” says Dai. By the time you get behind the wheel of a new EV, its battery has already travelled the world.
Reformulating and recycling can ease battery impacts
Batteries have a lot of room to improve. Researchers are actively working on adjusting the materials used in their manufacture, which could result in cheaper and less environmentally-costly cells. “The current trend is that they are trying to reduce the cobalt content in the active cathode material and increase the nickel content,” says Dai. This advancement could increase access to raw materials, as nickel is more widely available, lower battery costs, and increase vehicle range.
Reuse and recycling also present opportunities to reduce the environmental footprint of EVs. However, we don’t have enough EVs on the road right now for their batteries to generate a sizable recycling stream, says Dai. As the fleet grows, though, there may be potential to recover some materials. The valuable metals in batteries are much more concentrated than they are in raw ores, so being able to extract and reuse them would reduce the impacts of producing new batteries.
Milovanoff adds that at the end of an EVs use, the battery itself is not necessarily obsolete. The cells in the batteries could be extracted and reused for other purposes. But recycling is not an infinite, closed loop. At some point, the materials cannot be repurposed again, and will inevitably become destined for the landfill. “Those are limits dictated by physics,” says Milovanoff. “There will always always be a need for new primary materials from the critical materials.”
EVs are one part of sustainable transit ecosystem
If Americans solely rely on electric vehicles to decarbonize transportation, we’re going to need a massive number of EVs by 2050—350 million—which will in turn use half the national electricity demand and spike the need to mine critical elements like lithium, cobalt, and manganese, a recent analyses led by Milovanoff found. Reducing that drain on electricity and the impacts of mining those minerals requires reducing per capita car ownership and driving miles.
“Our society needs to rethink our dependence on automobiles,” says Watts. He thinks the solution to curbing transportation emissions will have to include shifting our infrastructure and policy away from supporting car-centric cities. “Over time, I’ve come to understand you can’t invest in car-centered infrastructure if you want people to drive less.”
It’s something that policymakers in Washington seem to realize.
There are a lot of places to start. Watts says providing people with more options is key—safe bike lanes and sidewalks, and reliable public transit. When cities add protected bike lanes, cycling increases. Zoning changes that allow for denser development with mixed uses—commercial properties and dwellings in close proximity—also reduce driving.
All that said, if you do find yourself needing a new car, an electric model will, over time, pay for itself in terms of emissions. One study found that in the UK a new Nissan Leaf pays back its “carbon debt” in less than two years of driving. “I got an EV myself,” says Dai. “Personally, I think I will try to convince all the people I know to drive an EV.”