Seattle is a green city, and not just because it rains a lot. Maybe it’s our extraordinary landscape, maybe it’s our history, maybe it’s a combination of these and other factors, but Seattle and its surrounding communities have long been politically green, and profoundly so. Except, it appears, when it comes to the thorny issue of urban density.
Counterintuitive as it may seem, the densest urban communities are also the greenest, making the most efficient use of both landscape and energy, a fact brought home by a recent study that compares the relative CO2 emissions between cities and their surrounding suburbs. Not surprisingly, our nation’s densest city is also by far our most energy efficient, with a CO2 emission differential of nearly 7 tons annually between the average city resident and that of the typical suburbanite.
In almost every metropolitan area, we found the central city residents emitted less carbon than the suburban counterparts. In New York and San Francisco, the average urban family emits more than two tons less carbon annually because it drives less.
[…] But cars represent only one-third of the gap in carbon emissions between New Yorkers and their suburbanites. The gap in electricity usage between New York City and its suburbs is also about two tons. The gap in emissions from home heating is almost three tons. All told, we estimate a seven-ton difference in carbon emissions between the residents of Manhattan’s urban aeries and the good burghers of Westchester County. Living surrounded by concrete is actually pretty green. Living surrounded by trees is not.
The policy prescription that follows from this is that environmentalists should be championing the growth of more and taller skyscrapers. Every new crane in New York City means less low-density development. The environmental ideal should be an apartment in downtown San Francisco, not a ranch in Marin County.
Of course, New York is the extreme, and due to our lower densities, temperate climate, and anemic, bus-centric transit system, the CO2 emission differential between Seattleites and our suburban counterparts is substantially less, amounting to about 2.5 tons annually per capita. But that’s a significant savings nonetheless, and one that will only increase as we let go of our single family home ideal, and eventually build up a denser, more energy efficient Seattle.
The shift to electric light rail will also make a huge difference, both by moving trips from cars to transit, and by shifting transit to cleaner electric power. In fact, one of the more interesting details in the study is that Seattle, while generally in the middle of the pack on other metrics, ranks amongst the top five cities in terms of the current CO2 differential from public transit, with city dwellers annually emitting 2,600 pounds more CO2 per capita than their suburban counterparts. Of course this is more than offset by the CO2 savings from reduced driving, but our relatively meager overall differential on combined transportation related emissions demonstrates how much room there is for improvement both within and without the city center.
While public transportation certainly uses much less energy, per rider, than driving, large carbon reductions are possible without any switch to buses or rails. Higher-density suburban areas, which are still entirely car-dependent, still involve a lot less travel than the really sprawling places. This fact offers some hope for greens eager to reduce carbon emissions, since it is a lot easier to imagine Americans driving shorter distances than giving up their cars.
Of course, apartment life is not for everybody, and I certainly empathize with residents concerned that rezoning to higher densities will change the character of their neighborhoods, but Seattleites should stop kidding themselves that this resistance to change comes without an environmental cost. The Denny Party originally dubbed their new settlement New York Alki, “alki” being the Chinook word for “eventually” or “by and by.” If supposedly green Seattle really cares about maintaining the landscape and natural splendor that is so important to our quality of life, it is time we let go of our 1950’s mentality, and embraced a little more of the Denny’s 1850 vision.