Urbanism in the Age of Climate Change: Vision California
Peter Calthorp
Streetsblog
01/26/2011
California’s effort to implement its new greenhouse gas reduction laws has provided a comprehensive look at urbanism and its potential in relation to a range of conservation and clean energy policies. The Vision California study, developed for the California High Speed Rail Authority and the California Strategic Growth Council, measured the results of several statewide land use futures coupled with conservation policies through the year 2050.5 The results make concrete the choices before us, the feedback loops, and the scale of both benefits and costs.
California is projected to grow by 7 million new households and 20 million people, to a population of nearly 60 million, by 2050.6 It is currently the eighth-largest economy in the world and therefore provides an important model of what is possible. The study compared a “Trend” future dominated by the state’s now typical low-density suburban growth and conservative conservation policies to a “Green Urban” alternative. This Green Urban alternative assumed that 35 percent of growth would be urban infill; 55 percent would be formed from a more compact, mixed-use, and walkable form of suburban expansion; and only 10 percent would be standard low-density development. In addition, the Green Urban alternative would push the auto fleet to an average 55 miles per gallon (MPG), its fuel would contain one third less carbon, and all new buildings would be 80 percent more efficient than today’s norm. It does not represent a green utopia, but it is heading in that direction. The results of this comparison highlight just how much is at stake and what the costs will be.
Remarkably, the quantity of land needed to accommodate the next two generations was reduced 67 percent by the Green Urban scenario, from more than 5,600 square miles in the Trend future to only 1,850 square miles. By comparison, the state’s current developed area is 5,300 square miles.7 This difference would save vast areas (up to 900 square miles) of farmland in the Central Valley along with key open space and habitat in the coastal regions of the state. The more compact future means smaller yards to irrigate and fewer parking lots to landscape, saving an average of 3.4 million acre-feet of water per year—enough to fill the San Francisco Bay annually or to irrigate 5 million acres of farmland.8 Less developed land also translates to fewer miles of infrastructure to build and maintain. The annual savings would be around $194 billion for the state, or $24,300 for each new household—not including the costs of ongoing maintenance. In addition, the Trend future would cost more in police and fire services as coverage areas increase.
Surprisingly, such a future would not dramatically change the range of housing choices available in the state. In fact, some would argue that the outcome would be more market responsive, providing a long overdue adjustment of housing types and prices. Specifically, while large single-family lots would decline from 40 percent of the total today to 30 percent in 2050, small-lot homes and bungalows would increase slightly and townhomes would double to 15 percent. Multifamily flats, condos, and apartments would actually end up the same, at around a third of the market. Overall, detached single-family homes would drop from 62 percent of all homes today to just over half. Many would conclude that this would be a reasonable shift, one ultimately making the housing stock more diverse and affordable—not, as some would argue, the end of the American dream.
In the Green Urban future, auto dependence drops dramatically—in fact, average vehicle miles traveled throughout the state would be reduced 34 percent, to 18,000 miles per household, from a Trend projection of 27,200. Closer destinations, better transit service, and more walkable neighborhoods all contribute to this significant shift. We would all still have cars, but they would be more efficient and we would use them less. The implication of this reduction in auto use is far-reaching. In terms of congestion, it is the equivalent of taking over 15 million cars off the road.9 There would be fewer roads and parking lots built, less land covered with impervious surface, and less runoff water to be cleaned and stored. The list of collateral benefits is long. In fact, the need for new freeways, highways, and arterials is reduced by 23,000 lane-miles, a saving of around $450 billion for the state.
Less driving means fewer accidents, in this scenario potentially saving around 3,100 lives and $5 billion in associated costs per year.10 Less driving means less air pollution and less respiratory disease.11 More walking means healthier bodies and less obesity, affecting diabetes rates and all of its associated health costs.12
Most significantly, the Green Urban scenario reduces carbon emissions and comes very close to achieving the 12% Solution in the transportation sector of the economy. When the savings in vehicle miles traveled are combined with low-carbon/high-MPG cars, emissions for transportation drop from more than 260 million metric tons (MMT) to just 29. Moreover, we would consume 352 billion fewer gallons of fuel over the next forty years, for a saving of over $2.1 trillion. These numbers are almost too big to imagine, but by way of comparison, the proposed high-speed rail system running from San Diego to San Francisco is projected to cost $42 billion, less than one-fifth the value of the potential annual gas savings. Put simply, at a projected $8 per gallon in 2050, these gas savings represent around $6,100 in savings per household.
