The folks who write the SMa.r.t Thinking column have many valuable things to say. However, they are not entitled to march under the banner of sustainability, as Thane Roberts attempts in his misleading column of June 11.

The basic concept of sustainability is that our social practices and habits of living be such that they can be continued by future generations. On a global level this means first and foremost our habits of energy consumption, both because we are currently dependent on non-renewable energy resources that will soon enough run out, and because the use of these forms of energy causes great harm to the natural environment, such as global warming. To call a practice sustainable is thus, in the main, to say that it minimizes energy use. Sustainable design of individual buildings — such as is recognized by LEED certification — is design that minimizes the energy consumption of the individual building. And sustainable urban planning is likewise the creation of cities where per capita energy consumption is minimized.

Mr. Roberts begins his article with the metaphor of a frog in a cauldron to evoke the global environmental crisis, but then, unfortunately, abandons this global perspective to go on to rehearse some reasons from a narrowly local perspective to perhaps not like high-density development.

This shift is unfortunate and misleading, because it’s a basic fact of global urbanism that higher population density of a city is correlated with lower per capita energy consumption. (Google “urban density energy consumption” to see images of the classic chart.) The denser a city is, the lower the amount of energy consumed by each of its residents, in general. Conversely, residents in low-density cities consume greater amounts of energy each, on average. Therefore, typically, the higher the population density, the more sustainable the city. Building densely is, far from being a threat to global sustainability, one of our main tools to advance it.

Of course, high density urban form can bring with it unpleasantries, some of which the folks at SMa.r.t. are not shy to detail. And sustainability is not the only criterion by which to measure cities. But architects and urban designers who do have a global conscience and do prioritize sustainability aren’t fighting to reduce the density of development in their cities. Quite the contrary, they accept density as a necessity, and focus their research and practices instead on understanding and addressing high density urbanism’s peculiar demands so that the cities that result are as far as possible livable habitats for their residents.

David William Martin
Santa Monica