Since you’ve probably let your subscription to the Journal of Industrial Ecology lapse, I’m here to tell you that the latest issue contains a study on the environmental benefits of the new breed of electric cars (the Nissan Leaf, Chevy Volt, plug-in Prius, etc.). Scientists at the Norwegian University of Science and Technology find that those EVs aren’t much better than conventional cars when it comes to carbon reduction and, if you throw in other forms of pollution, they’re actually dirtier.
Taking into account factors like the vehicles’ production and the generation of the electricity used to power them, electric vehicles’ decrease in global warming potential (GWP, as the study calls it) compared to gasoline or diesel automobiles is only 10-24%; i.e. over an electric vehicle’s lifetime, it will only produce one-tenth to one-quarter less climate-changing carbon than an old-fashioned, dinosaur-burning car. And that assumes today’s EVs have a useful lifetime is 150,000 kilometers, equal to 93,000 miles or about seven years of average driving time. When you slice that lifetime to 100,000 km (about 62,000 miles or five years), an electric vehicle’s GWP is only 9-14% lower than a gasoline car’s and is indistinguishable from a diesel’s.
Combine this with the study’s findings that electric cars, thanks in a large part to production and disposal of their batteries, “exhibit the potential for significant increases in human toxicity, freshwater eco-toxicity, freshwater eutrophication, 1I googled this one. It means an unhealthy increase in the amount of minerals and other substances absorbed by freshwater, leading to all kinds of negative effects on plantife and the ecosystem in general. and metal depletion impacts,” and suddenly EVs fade from a lovely forest green to a kind of pond-scummy myrtle.
It’s not news that a vehicle’s fuel efficiency doesn’t necessarily equate to a lower carbon footprint. 10% or more of a normal automobile’s lifetime carbon output comes from just manufacturing the car, but complex hybrid or electric vehicles fart out even more of their carbon footprint during production. Early generations of the Toyota Prius — thanks to their energy-intensive manufacture, the nickel mining involved to make their batteries, and the shipping required to get all their components together — produced a big carbon footprint that only shrunk to that of an all-gas car if the Prius was driven for close to its maximum useful life.
This hasn’t changed with modern electric vehicles. The new study finds that a full 50% of a new EV’s lifetime carbon output comes from its manufacture. Not surprising, considering that a 100% electric vehicle doesn’t release any emissions when you drive it. What is surprising, though, is that the electric car’s production carbon footprint is Sasquatch-sized compared to a conventional car. The Norwegian scientists found that manufacturing an EV creates more than twice the global-warming pollutants of manufacturing an internal-combustion car. That means an electric-car owner has a big carbon debt to make up from the moment they leave the showroom.
An EV owner pays off that carbon debt by driving emissions-free. Thing is, while an all-electric car itself doesn’t produce any carbon, generating the electricity used to run it does. Unless you’re lucky enough to live in an area powered entirely by carbon-neutral energy production (wind, solar, nuclear, etc.), the electricity flowing out of your home’s outlet and into your electric car comes from burning fossil fuels, mainly coal and natural gas. Those emissions need to be factored into the car’s carbon footprint. The study finds that if your power comes from natural gas, 2About a quarter of the country’s power does. an electric car’s lifetime emissions will be only 12% less than a gasoline-powered car and roughly equal to that of a diesel. But if your power comes from coal, 3Which produces over a third of the country’s electricity. your electric vehicle’s carbon emissions are actually 17-27% greater than a conventional car. That makes it really difficult to write off the EV’s carbon debt.
Those numbers are dismaying, but they don’t necessarily mean you shouldn’t buy an electric car. If you know your power comes from a clean source (or soon will) and you have the dedication and cash to keep an EV well maintained and on the road for many years, a Leaf or Volt might be a smart choice. 4The latter only if you’re familiar enough with your driving habits to know that you’ll rarely need to run on the gasoline backup. For most of us, though, instead of reaching for the latest “clean” car, the smartest way to go green in the automotive world is the same as for all things eco: reduce and reuse.
Reduce the production of new cars and the carbon it creates by reusing a car — in other words, when you want or need a new car, buy a reasonably efficient used one. Maintain that car to keep it running for as long as possible; the longer cars stay on the road, the less need there is for producing new ones. As part of that maintenance, reuse parts. Buy (or request from the shop) refurbished secondhand parts to further reduce manufacturing and waste. 5One rare benefit of modern corporate greed is that many insurance companies save themselves money by requiring secondhand parts for covered repairs. And if you get sick of your car before it gets sick and dies, sell it to someone who will make use of it.
If keeping the human race from dying out isn’t enough of a motivator for you, refocusing from a new car to a used one also saves money and is more fun. As an environmentally conscious driver, you aren”t bound to choose from the latest selection of “green,” expensive, and boring new automobiles pushed out by manufacturers. Your choice opens up to every car ever made. You can easily find a car the you can afford and, just as importantly, that you can love. Because the more you love your car the longer you’ll keep it healthy, which helps keep the planet healthy and Al Gore happy.
Here’s the car I love, my 1996 BMW 328i convertible. It gets about 21 mpg combined, has been running for 16 years and 115,000 miles and, with a little help from me, could probably double that. With luck that will get us to the point when clean cars are truly clean.
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|1.||↵||I googled this one. It means an unhealthy increase in the amount of minerals and other substances absorbed by freshwater, leading to all kinds of negative effects on plantife and the ecosystem in general.|
|2.||↵||About a quarter of the country’s power does.|
|3.||↵||Which produces over a third of the country’s electricity.|
|4.||↵||The latter only if you’re familiar enough with your driving habits to know that you’ll rarely need to run on the gasoline backup.|
|5.||↵||One rare benefit of modern corporate greed is that many insurance companies save themselves money by requiring secondhand parts for covered repairs.|