Electric cars won't make Seattle green

There's still a window where we can limit global warning to 1.5 C rather than 2 C. As David Roberts notes in that article, that half a degree means saving hundreds of millions of lives, prevents inundations of some islands and coastal areas, not to mention the affects on the wider environment. That half a degree seems worth it to me.

What would it mean for Seattle to meaningfully contribute to hitting that number? The main thing we need to do is electrify everything, with the underlying energy generated in a carbon neutral way. In Seattle, our utilities are already pretty good. All but a few percent of our power comes from renewable or non-emitting sources. Transportation and building energy use our are "big" sources:

Pie chart of carbon emissions in Seattle in 2014 by sector showing road transportation at 66% of the total with residential and commercial buildings making up most of the rest

Half is due to passenger vehicles. This includes our diesel buses, but over 95% of our emissions are due to cars and trucks, not mass transit (see table 1 in this document). Clearly the single biggest way Seattle can help save hundreds of millions of lives worldwide is to drive carbon emissions due to passenger transportation to zero as fast as we can. How fast? Some folks say the United States needs to be carbon free by 2035 to have any hope of holding warming to 1.5C (and the rest of the world by 2050). What would it mean for "passenger transport" in Seattle to not pollute carbon by 2035?

Clearly we will need to electrify all our public transportation. We're well on the way to that. The light rail and streetcars are already electrified. King County metro has numerous electric trolley buses and is planning to have an all-electric fleet. I believe we'll manage to electrify public transit rapidly.

I am not so sure we'll take all the gas-powered cars off the road. Earlier this year, Seattle Mayor Durkan announced a climate plan. The near term action summary was, in my opinion, pretty unambitious for an incredibly wealthy city. In summary, the actions relevant to transportation are (see table 1):

That's it. 2035 is not very far away. No actions mention transit or walking or biking. Somehow cars will just magically become electrified.

But what would it mean to replace all gas powered cars traveling in Seattle with electric ones? Let's leave out folks just driving through on I-5 since we can't actually do anything about that. How many gas powered cars are there anyway? The state doesn't provide per city data (I emailed for it) but they have reports with county data online. There are about 1.5 million gas powered non-commercial cars and trucks registered in King County in 2017. Lest you overestimate the prevalence of those flashy Teslas, less than a percent of cars and trucks are electric already.

I would hazard to guess that two thirds or more of those vehicles travel in Seattle at least sometimes. Gene Balk estimated in 2017 that the car "population" of Seattle is around 435,000 (cars registered to residents of Seattle). On any given day, many more cars drive into the city from (mostly King County) cities and towns. So let's be generous and say there are a 750,000 gas cars or trucks that regularly drive in Seattle.

To hit that 2035 number, every one of those cars has to be trashed – meaning they can't be sold and driven by someone else – and replaced with a fully electric car. I did some quick research and a smallish electric car (four door) costs about $27,000 (before options or taxes). Let's be conservative and say that over the next decade or so the average cost of an electric car goes down to $20,000 in today's dollars. I think this is pretty unrealistic for a lot of reasons, not least the huge amount of demand will cause an upsurge in prices for everything involved in electric car manufacturing, but let's go with that because I like round numbers. (Savvy readers will also note I'm completely glossing over the carbon pollution from car manufacturing.)

Replacing 750,000 cars would thus cost $15 billion. With a B. Now, who is going to pay this? Even if your family can afford it, would you want to replace you relatively new Prius hybrid with a fully electric one? Because even those are polluting. You're going to need an incentive, and a pretty strong one, to be willing to spend $20k. If you can't afford a new car, why would you replace it at all? We aren't going to just tax the poor until they give up their polluting cars (who am I kidding – we might). But the point is, if we are serious about replacing all those carbon polluting cars with electric ones, then the city will have to plan to spend a substantial portion of that $15 billion (note that Seattle's yearly city budget is currently only about $6 billion, half of which is the city utilities). In, say, the next ten years.

Or we could instead (off the top of my head) take meaningful near term actions:

These would still cost a lot of money, but then we'd be investing in public goods, not subsidizing private ownership of cars that will still be dangerous to everyone using our streets, even if they aren't as polluting.