In the 1970s, the progressive view was to get people out of the city and back to the land, to grow your own food, make your own power, and retreat from the devastation wreaked by cities on the environment. The idyllic life waited where the pavement ended, and many of those who embraced that lifestyle moved to Marin. We didn’t realize then what we know now: cities are our best hope for the future, and that where we live is intimately connected with the health of our planet and our communities. As Marin engages in a great and necessary debate over regionalism and housing, it is important that we not choose self-destructive conservatism over conservation. The conservative line is that Marin cannot accommodate anyone else, and that growth must remain slow or stagnant for the good of the county and the planet. Bob Silvestri, a Mill Valley community activist, has said that density and transit-oriented development are bad for the environment and increase, rather than reduce, greenhouse gas emissions. Greenhouse gases, he says, should be limited in industry and power but not in our personal lives. Accommodating more people in Marin would ultimately increase our carbon footprint per capita and reduce our overall quality of life.
The conservationist line is that people will move somewhere, and Marin is better placed that elsewhere to limit sprawl at the outskirts of the region. Density brings more efficient use of infrastructure and energy, happier and healthier people, and a more dynamic city. The Natural Resources Defense Council actively advocates for more compact towns and cities through infill development, arguing that they reduce overall energy usage and keep open space safe from development.
Everything I have seen since leaving Marin has shown me that the conservationist's view conforms more closely with reality than the conservative's. From walkable city centers to small towns in Vermont, the best places, the areas where I felt most at home, were the ones that were more compact, where housing is within walking distance of stores, offices, parks, schools, and mass transit.
Having amenities and housing within walking distance of each other is itself a good. Though you could ask a patron of Sun Valley Market or a resident of downtown Mill Valley, or think back on that European trip, you could also look at a 2011 research review from the Victoria Transport Policy Institute. It says, in part, that promoting walking as part of everyday life, such as in a daily commute, has measurable health benefits. A study from New Zealand showed that for every mile walked rather than driven the country saves 48¢, and for every mile biked the country saves 19¢. Given the higher health costs in the US, that could be significantly higher.
Walkers also spend more. A study from the United Kingdom, also cited by the Victoria review, shows those who primarily walk to shop spend £91 per week while those who principally drive spend only £64 per week. Given that the shoppers are walking, they will necessarily support whatever retail is nearby. Infill development near town centers, then, will bring shops their best customers. Others have described that bicyclists also spend more than drivers. Encouraging walking and biking to and around a downtown, then, will be a local economic stimulus. Providing housing in or near downtown will install permanent, well-paying, healthier customers for retailers.
Environmentally, housing location and housing density matters as well. If we avoid greenhouse gasses and transportation for a moment, we find that denser and more walkable housing decreases the amount of runoff per-capita and decreases the amount of lawn fertilizers and such that get washed into waterways. A single paved acre will cause just as much runoff whether it has 1 family or 30 living on it. Spreading those 30 families out to 30 different houses that need roads connecting all of them and parking lots to store their cars (an average of three are built for every car added to the road) will result in far more than a single acre of impervious surface.
Greenhouse gases are trickier to tease out. While studies (PDF) show (PDF) that transportation-related greenhouse gases drop precipitously once people move away from car usage, Silvestri recently cited a study of New York City that finds higher rates of greenhouse gas emissions per capita than lower-density developments. This directly contradicts studies done by the United Nations, New York City itself, and many others. I couldn't find the New York City study, but similar research done on Australia finds essentially the same point. In such instances, it is the common energy consumption - common areas, parking garages, and the like - that sucks up the excess energy, as well as increased overall consumption. A broader study (PDF) examining the United States find an opposite relationship, so it may be that Australian development patterns are not translatable to the American urban reality.
Parsing the two opposite conclusions is not the thrust of this piece. Suffice it to say that the bulk of research shows that the location and type of housing influences greenhouse gas emissions. In addition, the densities Marin is contemplating are nowhere approaching Manhattan or Melbourne, and so would fall into the bottom of any conceivable greenhouse gas U curve. Building more densely would decrease greenhouse gas emissions in transportation - the research on that is essentially unanimous - and any additional costs can be made up in green building strategies that ought to be standard in Marin to begin with.
Lastly, housing location determines how much open space is preserved. Though our region could go sprawling through the hills of the East Bay and into the Central Valley, it is concomitant upon the already existing towns and cities to build where infrastructure already exists, even if in relatively low densities. It saves money for the cities out on the edge (just ask Stockton how its sprawl is paying for itself) and preserves open space in areas where land trusts do not tread. Pushing a slow-growth agenda in Marin just means pushing a faster-growth agenda everywhere else. The Bay Area will grow, and I'd rather see it happening along Miller Avenue than on Central Valley farmland.
Where conservatives and conservationists ought to agree is that local control is a good thing. We shouldn’t need regional agencies telling us what to do. Affordable housing mandates do little to increase affordable housing, and inclusionary zoning decreases the amount of housing built, driving up the market price. Sacramento should stop raiding our housing budgets and allow localities to actually build.
But we cannot be so blinded by the important pursuit of local control that we lose sight of the connections that tie Marin to the rest of the region and country and world. How and where we build our housing is intimately connected to the health of our residents, the health of our planet, and the health of our communities, and for every resident we turn away another home must be built elsewhere, and there's no guarantee that other place will be as socially conscious as we are.
Keeping the drive through that was always there just because it was always there is not a recipe for sustainability; it’s a recipe for stagnation. That’s exactly what we’ll get if the county’s conservatives have their way, and we’ll become environmentalists concerned more about preserving our parking lots than preserving the Delta, or coastal San Mateo, or rural Napa, or the Great Plains, health nuts unconcerned by active living, and citizens unmoved by the hardship of downtown merchants. That's not a Marin I would recognize.