Tesla Motors has an army of loyalists who either swear by the company’s sleek and stealthy high-end luxury electric cars or dream of getting their hands on one. They share company co-founder Elon Musk’s vision of ending the 130-year reign of the internal combustion engine by steering drivers away from gasoline and toward electricity.
But hold on to your smugness, Tesla owners. Not all electric cars are the same, and until the U.S. more fully embraces renewable energy sources, buying an electric car isn’t necessarily the greenest option out there. In fact, some hybrid vehicles can be greener options than fully electric cars, according to people who study the sources of carbon emissions that cause global warming. (Sorry climate deniers, you’ve lost that debate.)
Important factors in determining carbon emissions include the weight of the vehicle, driving habits, and the source of the electricity that charges your car. Likewise, it can be a much greener choice to keep the perfectly functional car you have, rather than go out and buy a new one.
“If you are a relatively low-mileage person, you should stick with your gas-powered car,” Mike Berners-Lee, a leading expert in measuring the amount of greenhouse gases released by the products we buy, told Salon. “When the time comes to buy a new car, you should buy a nice, small electric car, and you should still keep the mileage down. You should still try to find other forms of transport when you can, and you should share transportation as much as you can.”
One of the reasons why buying a new car is a problem is the vehicle’s so-called embodied carbon, meaning all of the energy that was used to build the car from scratch — including the extraction and processing of raw materials, and shipping parts and vehicles across oceans in filthy bunker-fuel burning cargo ships. Every time you roll off the dealer’s lot in a new set of wheels — electrified or not — your personal carbon footprint grows immensely.
Berners-Lee, the British author of “How Bad are Bananas?: The Carbon Footprint of Everything,” calculated that making one midsize sedan like the Ford Mondeo (known in the U.S. as the Ford Fusion) generates about 17 metric tons of carbon dioxide; three year’s worth of gas and electricity consumed by a typical British household produces about the same amount. In general, the amount of carbon it takes to manufacture a car scales depending on its mass: an SUV like the Land Rover Discovery creates about twice the carbon yield of the Ford Mondeo merely in production, where as a compact car only yields about 6 metric tons of carbon.
Electric cars aren’t much different than gas-burning vehicles in this regard. In fact, the U.S. Union of Concerned Scientists estimates that it takes about 15 percent more embodied carbon to produce an electric vehicle (EV) than it does to manufacture a gasoline-powered car, largely because of the materials and fabrication processes used to make the battery packs.
“For a full-size [electric] car, it can be a higher percentage increase in the emissions” of embodied carbon, David Reichmuth, senior engineer in the Clean Vehicles Program at the Union of Concerned Scientists, told Salon.
However, Reichmuth is quick to point out that while an electric car is modestly more polluting to manufacture, it more than makes up for the difference over the life of the vehicle. A study Reichmuth co-authored and released in 2015 shows that by the time a mid-size electric car hits 135,000 miles, it will have produced half of the emissions of a comparable gasoline-powered sedan.
