» Does the $25,000 fully electric Nissan Leaf muddle environmental arguments in favor of transit?
Nissan’s new Leaf, expected to reach American shores this December, represents nothing less than a revolution in thinking about automobile propulsion: it is the first modern, reasonably priced, four-door car powered completely by electricity. It is the opening slide in what is likely to be an avalanche of such vehicles coming to market over the next decade — Chevrolet’s electric-for-40-miles Volt is arriving later this fall as well at a higher price point. The significance of their collective potential environmental benefits cannot be dismissed.
The immediate consequences of the replacement of at least a segment of the American vehicle fleet with electric cars will be positive: an immediate elimination of local point-source pollution, lessened street noise in the urban environment, and of course a reduction in the consumption of fossil fuels, at least by individual consumers. These are advances that must be applauded.
The widespread availability of electric cars will make one argument made by transit proponents harder to advance: that riding trains and buses is better for the environment. In cities where the electric grid is powered by renewable or nuclear energy, these vehicles will produce zero carbon — also true of electric trains, but not of diesel or even hybrid buses, which will continue spewing pollutants into the atmosphere.
But transit must continue to compete from an environmental perspective, or it will lose some of its appeal; the arrival of the electric car is a direct challenge to the claim that public transportation is greener. But it’s not too late to make that argument — there are significant ecological advantages of mass transit even if they share their propulsion technologies with some automobiles. The contention that transit is the more sustainable answer to questions of mobility has not suddenly expired.
The clearest flaw in the argument for electric cars is that the majority of electricity produced in the United States — almost 75% — comes from power plants that burn fossil fuels. This means that “clean” cars like the Nissan Leaf are simply shuffling pollution production elsewhere, not actually getting rid of it. This would not be true if American power were produced like it is in France, where about 90% of power is carbon-free, and where a switch to electric cars would mean a vast reduction in air pollution overall. At least for now, though, the widespread adoption of electric cars in the U.S. will require a large ramping-up of power generating capacity and therefore increase pollution from power plants, not necessarily generating a net benefit, even as there is a significant decrease in air pollution in congested urban areas.
If all transit vehicles switched to electric propulsion and public transportation absorbed a much larger percentage of the commute market, on the other hand, they would require less overall electricity because they’re more energy efficient per passenger. So even if everything were electrically powered, transit would still have some advantages.
Second, electric cars may be environmentally responsible in operation, but their manufacturing and disposal require a significant energy expenditure: between 10 and 20% of overall lifetime energy use. Transit vehicles last longer and are used more intensely than automobiles, meaning that their per-rider-mile manufacturing and disposal costs are significantly lower than those of cars.
But all of the discussion about the relative ecological advantages of cars and public transportation vehicles ignores their greater effects on the human environment, and that is the basis of the primary argument transit proponents must use to defend the environmental credibility of buses and trains. Transit nurtures the creation of dense urban environments in which the majority of trips are made by carbon-free walking and in which people live and work in energy-efficient multi-story buildings. A society dependent on automobiles cannot establish such sustainable communities and will ultimately always depend on energy-heavy single-family homes and private vehicles. There’s no getting around that fact, Nissan Leaf or not.
Electric vehicles could play an auxiliary role as the basis for new car-sharing efforts, but the implementation of electric chargers on the street for private users seems far off. Nissan and other auto companies are expecting most of their customers to refill their vehicles in their private garages overnight, not exactly an urban-friendly scheme.
Nevertheless, transit agencies still have an obligation to increase the efficiencies of their vehicle fleets — primarily by increasing ridership and maximizing the number of riders per bus or train. There’s nothing wrong with finding as many ways as possible to reduce energy consumption.
Image above: Nissan Leaf, from Nissan