...the full electric conversion would cut Seattle’s road transportation emissions about in half, which would reduce the City’s total carbon footprint by about one fifth.

Of course, there are also many downsides left out of the above analysis:

• There are significant GHG emissions resulting from car use in addition to those associated with simply propelling the car. For example, Toyota estimates that manufacture accounts for 30 percent of a Prius’ lifetime GHG emissions. In addition, the infrastructure required for cars is a source of GHG emissions—one study estimates that roadway construction and maintenance adds another 26 percent to the GHG emissions associated with operating a conventional car.


• Rising fossil fuel costs and carbon pricing will inevitably result in rising demands on carbon-free electricity from all sectors, and electric vehicles may end up competing for energy needed to supply the basics, such as heating homes.


• The Puget Sound region is projected to grow by 1.6 million people by 2040, an increase of more than 40 percent. If we do nothing other than convert our fleet, we can expect VMT to rise proportionally. And in this scenario, we’d have to choose between a massive amount of road building or total gridlock. Note that this this scenario would also mean a forty-plus percent increase in electricity consumed by electric vehicles.


• Electric cars are expensive (it’s all about the batteries). A new $30k electric car for every Seattle household would cost about $9 billion—more than twice the City's total annual budget of $3.9 billion.


• And lastly, electric cars, like conventional cars, inherently cause a host of negatives, including accidents, high cost of ownership, sedentary lifestyles, social isolation, land consumption, impervious pavement, and the proliferation of terrible urban design.

In the long term however, it is delusional to think that we can go on with car-centric business as usual if we simply switch to electric vehicles. Indeed, our future prosperity will be determined to a large degree by how successfully we reduce reliance on cars. And that means reshaping our urban areas such that (1) people can meet many of their daily needs with short trips that can be made on foot or bike, and (2) convenient public transit is available for longer trips. (Hint: some folks like to call such places transit-oriented communities.)