JAMES CARNAHAN
Charged to figure out how to transform our vulnerable suburban community into a genuinely resilient urban one, the Chapel Hill Community Sustainability Visioning Task Force suspended its important work in mid-April (“Sustainability panel is at a crossroads,†4/15/10), primarily due to concerns about “carrying capacity.†But using carrying capacity to determine whether more or less development should take place in Chapel Hill, Carrboro or Orange County is to transform a cautionary principle into an exclusionary one.
Task force members said, in effect, that we should not make decisions about density along transit corridors until we have calculated how many people we can sustain in Chapel Hill and its surrounds in the future. For instance, will we have enough water to support more people, some members asked. Unfortunately, applying carrying capacity this way is loaded with unintended consequences for our society, economy and even the environment.
In fact, the way we manage growth already excludes the lesser among us. Promoting mixed uses and higher densities could generate more small businesses and smaller residences, supporting more transit, but our ordinances discourage this approach. The constraints on starting a business or building downtown, in combination with the costs of important public services (e.g., schools), drive up the price of admission – or, for those of us already here, escalate living costs beyond our means.
Carrying capacity can only be reliably determined if the system is closed to outside influence. Modeling the carrying capacity of a particular jurisdiction would be very complex and yield ambiguous results. Any model would have to account for ongoing technological advances, the sources of goods and services, changes in behavior that would impact demand for natural resources and the ways waste and other residuals might be disposed of in the future. Past experience indicates such a model would be expensive and likely to have a short shelf life.
There might be some argument for determining carrying capacity at the larger geographic scale of a region or continent. But towns and counties straddle environmental designations such as watersheds, and their commerce is tightly interwoven with surrounding communities. The idea of “local carrying capacity†assumes these connections could be severed and that it is desirable to do so.
If the model tells you that you have exceeded or will exceed your arbitrarily defined area’s carrying capacity, there are moral and ethical implications to taking action. Would we prevent future growth or somehow reduce current population? How would we decide who gets to join us or remain here?
Meanwhile, our atmosphere’s ability to absorb carbon has already been surpassed, and the U.S. is by far the highest per-capita emitter of greenhouse gasses (GHG). Technological advances resulting in energy efficiency have been overtaken by increased emissions from more vehicle miles traveled (VMT) by our cars and trucks. In Orange County, where low-density suburban sprawl is as ubiquitous as anywhere else, transportation produces 49 percent of our GHG emissions.
Research shows that VMT is reduced where uses are mixed, density is higher and sidewalks, bike lanes and public transit are present. Communities that have the lowest per-capita CO2 emissions are the densest. They mostly predate the automobile becoming the dominant form of personal transportation and have great, human-scaled environs. Much of what has been developed since World War II is phenomenally wasteful of all the ecosystem services on which human life depends, clean air included. That development is in many ways, hardly “livable.â€
Although water is frequently cited as a limiting resource, the detached single-family homes still favored by our ordinances are far bigger water gluttons than other forms of residential development. Moreover, water treatment, conservation and re-use technologies are rapidly evolving and are most efficiently implemented in larger projects where users are close together.
It is a serious mistake to get bogged down in a debate over whether to permit more people inside our cozy borders and also has xenophobic implications. Carrying capacity’s best use is as a cautionary precept to guide us toward the most efficient civilization possible, not as an exclusionary device to further increase the hurdles of providing for one’s family in Orange County.
Let’s use what we already know to figure out how and where we want this great adaptation to unfold. Let’s redesign our communities so that they invigorate and nurture our citizenry, rather than isolating and excluding us. This reshaping of the built environment should be a top priority for the Chapel Hill Town Council and other leaders serving the people, and deciding the future, of Orange County.
James Carnahan is a founder of the Village Project and former chair of the Carrboro Planning Board.