How Much Better Are Electric Cars for the Environment?

Electric vehicles (EVs) have been hailed as a key tool in the transition towards a greener future. But how much better for the environment are EVs, and are they a sustainable solution?

In terms of carbon emissions over a vehicle's total lifetime—including the manufacturing process—electric vehicles tend to win out over fossil fuel guzzlers, experts told Newsweek, although the picture can be somewhat complicated depending on a number of factors, including the local energy mix where you live.

"As electric cars run on electricity, the carbon footprint of the electric car when running depends on where the electricity comes from," Vera O'Riordan, a PhD student at the Marine and Renewable Energy Institute based at the University College Cork, who is low -carbon passenger transport modelling, told Newsweek.

"The carbon footprint of electricity depends on the fuel mix used in making the electricity. Electricity made from renewables is better than electricity made from natural gas, which in turn is better than electricity made from diesel, which in turn is better than electricity made from coal."

An electric vehicle
Stock image: An electric vehicle. How environmentally friendly are electric vehicles? iStock

One study released last year by the International Council on Clean Transportation, which looked at electric vehicles and petrol cars over their lifetime, found EVs have lower life-cycle greenhouse gas emissions.

The study found that in the United States, lifecycle emissions for EVs are 60-68 percent lower than petrol cars.

Jeremy Michalek, a professor with Carnegie Mellon University, who directs the Vehicle Electrification Group, told Newsweek that electric vehicles in the United States tend to have lower carbon footprints on average than gasoline or diesel cars, although there are exceptions.

One 2016 study authored by Michalek and colleagues contains maps showing that in general, "plug-in vehicles tend to reduce carbon emissions for city drivers in the Southwest, Texas and Florida, especially when compared to a typical gasoline car, whereas plug-in vehicles tend to increase carbon emissions for highway drivers in rural counties of the Great Planes, the Midwest and the South, especially when compared to gasoline hybrids, which are very efficient," he said.

"These maps are from the past, however. EVs have an advantage going into the future. As the power grid gets cleaner, as we expect it to, EVs will get cleaner as well. The most important factor for electric vehicle life cycle emissions is coal retirement. The more coal that retires, the cleaner EVs look."

Alan Jenn, an assistant professional researcher at the Plug-in Hybrid and Electric Vehicle group of the Institute of Transportation Studies, University of California, Davis, told Newsweek the answer to the question of whether EVs or fossil fuel-burning vehicles produce more emissions over their lifetime is somewhat complex, because it depends on two main assumptions.

The first is what car you are replacing with an EV, and the second is where the electricity to fuel the battery comes from.

"In the most pessimistic studies, an EV charging only on power from a coal plant would be about the equivalent of a 30 miles per gallon vehicle," Jenn said. "However, most studies typically find EVs don't go very far below the equivalent of about 80 miles per gallon in the United States, which is cleaner than any gas car on the market today."

"Even in the worst regions, one of the big upsides of electric vehicles is that the U.S. electricity grid is becoming cleaner and cleaner over time, which only improves these calculations in future forecasts."

Can Electric Vehicles Cut Pollution?

One of the big benefits of electric vehicles over gasoline vehicles in addition to carbon emissions is the reduction of local air pollutants, according to Jenn.

"When fossil fuel combustion occurs, it not only releases carbon dioxide (a greenhouse gas which leads to global warming) but compounds like nitrogen oxides, carbon monoxide, and particulate matter (local air pollutants which lead to negative health outcomes in exposed communities).

"These can be particularly impactful for electrifying heavy-duty diesel vehicles and can potentially improve the air quality in communities that traditionally suffer from low air quality," he said.

Michalek also said electric vehicles have the potential to "dramatically" reduce traditional air pollution, but it really depends on the power source.

An electric vehicle charging port
Stock image: An electric vehicle charging port. Electric vehicles can help to cut pollution in urban environments. iStock

Then there is the question of manufacturing electric vehicles, which require large quantities of resources, and also produces emissions.

"Manufacturing electric vehicles generally involves more air emissions than manufacturing gasoline vehicles, primarily because producing large battery packs is energy intensive and involves emissions from processes such as smelting," Michalek said.

"But for both electric and gasoline vehicles the majority of emissions come from using the vehicle, not manufacturing the vehicle.

"Emissions from producing electric vehicle batteries are an important part of overall life cycle implications, but the use phase is the larger factor, so getting electricity to charge the vehicle from a clean source can more than make up for the higher production emissions," he said.

According to Jenn, the local impacts and sustainability of material extraction for EVs certainly present a different set of issues compared to gasoline vehicles.

"Some researchers argue that the benefits from mitigating climate change might outweigh some of these issues, but that certainly doesn't dismiss their importance," he said.

"Many battery suppliers and automakers are trying to improve the sustainability of the battery production process by doing things such as reducing the use of more problematic materials—such as cobalt, whose extraction faces many human rights concerns."

In any case, O'Riordan said transitioning to electric vehicles can only be part of the transport solution if the world is to reach its climate targets.

"Avoiding the need for travel in the first place through demand reduction, and enabling a modal shift to public transport and active modes of travel is also needed as part of our low carbon transition. In fact, first and foremost, we need to design our urban spaces and work cultures in such a way that the need for car use and travel in general is brought down as much as possible in the first place."