Monday, March 11, 2013

Virtuous Polluters

People who drive electric cars feel especially virtuous. They feel that they are making a sacrifice in order to save Mother Nature.

The truth lies elsewhere. Bjorn Lomberg crunches the numbers this morning in the Wall Street Journal and shows that those non-polluting electric cars really pollute more than gas-powered vehicles.

In Lomberg’s words:

A 2012 comprehensive life-cycle analysis in Journal of Industrial Ecology shows that almost half the lifetime carbon-dioxide emissions from an electric car come from the energy used to produce the car, especially the battery. The mining of lithium, for instance, is a less than green activity. By contrast, the manufacture of a gas-powered car accounts for 17% of its lifetime carbon-dioxide emissions. When an electric car rolls off the production line, it has already been responsible for 30,000 pounds of carbon-dioxide emission. The amount for making a conventional car: 14,000 pounds.

While electric-car owners may cruise around feeling virtuous, they still recharge using electricity overwhelmingly produced with fossil fuels. Thus, the life-cycle analysis shows that for every mile driven, the average electric car indirectly emits about six ounces of carbon-dioxide. This is still a lot better than a similar-size conventional car, which emits about 12 ounces per mile. But remember, the production of the electric car has already resulted in sizeable emissions—the equivalent of 80,000 miles of travel in the vehicle.

After a time, it evens out, but only if the car’s owner avoids electricity produced by coal. Since roughly half of America’s electricity comes from coal, that is not very plausible.

But then, Lomberg continues, if an electric car owner does the environmentally friendly thing, the savings in carbon dioxide emissions are miniscule.

Lomberg explains:

Even if the electric car is driven for 90,000 miles and the owner stays away from coal-powered electricity, the car will cause just 24% less carbon-dioxide emission than its gas-powered cousin. This is a far cry from "zero emissions." Over its entire lifetime, the electric car will be responsible for 8.7 tons of carbon dioxide less than the average conventional car.

Those 8.7 tons may sound like a considerable amount, but it's not. The current best estimate of the global warming damage of an extra ton of carbon-dioxide is about $5. This means an optimistic assessment of the avoided carbon-dioxide associated with an electric car will allow the owner to spare the world about $44 in climate damage. On the European emissions market, credit for 8.7 tons of carbon-dioxide costs $48.


Anonymous said...

How about the carbon emissions to scrap the car when its usefull life is over?

Rusty Pritchard said...

As usual, Lomborg overreaches a bit in an attempt to make headlines, and no one bothers to fact check him. Hybrid cars aren't a panacea--we can't drive our way out of our pollution problem. But they do help. The only thing smugger than a Prius owner is a Prius critic...