Greening the City By Building More Stuff

Dave Alpert reports that DC City Council member Mary Cheh is looking for ideas about how to make Washington, DC greener:

The DC Council wants your bold ideas for greening the District of Columbia. On Friday, July 10th, Councilmember Mary Cheh’s Committee on Government Operations and the Environment and GW’s Office of Sustainability are hosing a “Policy Greenhouse” where ten people get to present their 5-minute big ideas.

The ideas need not be quick fixes, they emphasize, but rather ideas that would have a significant impact on the environment or introduce significant innovation. The site lists congestion pricing, vertical farming, “expanded retro-commissioning” (I’m not sure what that is), requiring carbon neutrality for public buildings, or “cool cars” that reflect solar energy as examples of the kinds of ideas.

I think the most important environmental policy insight that the DC government could make is simply to realize that the District, which contains only about 10 percent of the total population of the metropolitan area, has very little influence over the aggregate quantity of stuff that gets built in the metro area. The rate of job growth and population growth in the region is largely driven by independent factors. What DC policy influences is not the total quantity of stuff in the region but what proportion of the stuff winds up located in DC as opposed to located elsewhere in the region. And when you look at it, even without any additional “greener” it’s more ecologically sustainable for an additional household to locate itself in the District than to locate itself in Loudon County. Similarly, it’s “greener” for a new office building to be built in DC than to be built in Tyson’s Corner.

Under the circumstances, the “greenest” thing DC can do is simply to try to attract more stuff into the District—to try to encourage an increase in the quantity of housing units and office space located in DC as opposed to elsewhere. There are various levers to do that, but two measures that suggest themselves are to eliminate or sharply curtail regulations mandating the construction of parking as part of new developments (obviously some parking would still be built without regulatory mandates, but at the margin you’d have more development and less parking) and to permit the construction of taller buildings in the central business district and near Metro stations. Not only is development in DC “greener” than development in the suburbs and exurbs, but increasing the density of DC will make DC “greener” on a per capita basis by decreasing (on average) the distance people need to travel to get to stuff.

Additional measures to reduce the ecological footprint of existing District residents and employers—the sort of thing the Council seems to be primarily looking at—are nice, but the biggest game-changer would be to increase the proportion of DC area jobs and people that are actually located in DC.