Urbanism and Climate Change
I take as a given that climate change is an imminent threat and potentially catastrophic— the science is now clear that we are day by day contributing to our own demise. In addition, I believe that an increase in fuel costs due to declining oil reserves is also inevitable. The combination of these two global threats presents an economic and environmental challenge of unparalleled proportions—and, lacking a response, the potential for dire consequences. These challenges will in turn bring into urgent focus the way our buildings, towns, cities, and regions shape our lives and our environmental footprint. Beyond a transition to clean energy sources, I believe that urbanism—compact, diverse, and walkable communities—will play a central role in addressing these twin threats. In fact, responding to climate change and our coming energy challenge without a more sustainable form of urbanism will be impossible.
Many deny either the timing or the reality of these challenges. They argue that global demand for oil will not outstrip production and that climate change is overstated, nonexistent, or somehow not related to our actions. Setting aside such debates, this book accepts the premise that both climate change and peak oil are pressing realities that need aggressive solutions.
The two challenges are deeply linked. The science tells us that if we are to arrest climate change, our goal for carbon emissions should be just 20 percent of our 1990 level by 2050. That, combined with a projected U.S. population increase of 130 million people, means each person in 2050 would need to be emitting on average just 12 percent of his or her current greenhouse gases (GHG)—what I will call here the "12 % Solution." If we can achieve the 12 % Solution to offset climate change, we will simultaneously reduce our fossil-fuel dependence and demonstrate a sustainable model of prosperity. Such a low-carbon future will inherently reduce oil demands at rates that will allow a smoother transition to alternative fuels—and the next economy.
In addition to these twin environmental challenges, the United States has two other systemic forces to reckon with in the next generation: an aging population and a more diverse middle class with less wealth. We are now a country in which a third of the population are baby boomers or older and less than a quarter are traditional families with kids. And for the past decade, median income has actually fallen; in fact, "the typical American household saw its inflation-adjusted income decline by more than $2,000 between 1999 and 2008." So, at the same time that we must respond to climate change and rising energy costs, we must also adjust our housing stock to fit a changing demographic and find a more frugal form of prosperity.
Such a transformation will require deep change, not just in energy sources, technology, and conservation measures but also in urban design, culture, and lifestyles. More than just deploying green technologies and adjusting our thermostats, it will involve rethinking the way we live and the underlying form of our communities. The good news is that our environmental, social, and economic challenges have a shared solution in urbanism. Shaping regions that reduce oil dependence simultaneously reduces carbon emissions, costs less for the average household, and creates healthy, integrated places for our seniors: one solution for multiple challenges.
The urban solution involves both technology and design. For example, we will need to dramatically reduce the number of miles we drive as well as develop less carbon intensive vehicles. It will mean living and working in buildings that demand significantly less energy as well as powering them with renewable sources. It will involve the kinds of food we eat, the kinds of homes we build, the ways we travel, and the kinds of communities we inhabit. It will certainly involve giving up the idea of any single "silver bullet" solution (whether solar or nuclear, conservation or carbon capture, adaptation or mitigation) and understanding that such a transformation will involve all of the above—and, perhaps most important, that they are all interdependent.
In fact, the viability of new technologies and clean energy sources will depend on the success of our conservation efforts at the regional, community, and building scales, which in turn will be determined by our basic lifestyles and the urban forms that support our changing demographics. The key will be designing the right mix of strategies, a "whole systems" rather than a "checklist" approach to climate change, energy, and economics.
There are three interdependent approaches to these nested challenges: lifestyle, conservation, and clean energy. Lifestyle involves how we live—the way we get around, the size of our homes, the foods we eat, and the quantity of goods we consume. These depend in turn on the type of communities we build and the culture we inhabit—degrees of urbanism. Conservation revolves around technical efficiencies—in our buildings, cars, appliances, utilities, and industrial systems—as well as preserving the natural resources that support us all, our global forests, ocean ecologies, and farmlands. These conservation measures are simple, they save money, and they are possible now. The third fix, clean energy, is what we have been most focused on: new technologies for solar, wind, wave, geothermal, biomass, and even a new generation of nuclear power or fusion. These energy sources are sexy, they are relatively expensive, and they will be available sometime soon. All three approaches will be essential, but here I focus on the first two— lifestyle and conservation—because they are, in the end, our most cost effective and easily available tools.
The intersection of lifestyle and conservation is urbanism. Consider that in the United States industry represents 29 percent of our GHG emissions; agriculture and other non-energy-related activities, just 9 percent; and freight and planes, another 9 percent. This 47 percent total represents the GHG emissions of the products we buy, the food we eat, the embodied energy of all our possessions, and all the shipping involved in getting them to us. The remaining 53 percent depends on the nature of our buildings and personal transportation system—the realm of urbanism. As a result, urbanism, along with a simple combination of transit and more efficient buildings and cars, can deliver much of our needed GHG reductions.
Perhaps just as important as greenhouse gas reductions and oil savings is the fact that urbanism generates a fortuitous web of co-benefits—it is our most potent weapon against climate change because it does so much more. Urbanism's compact forms lead to less land consumed and more farmland, parks, habitat, and open space preserved. A smaller urban footprint results in less development costs and fewer miles of roads, utilities, and services to build and maintain, which then leads to fewer impervious surfaces, less polluted storm runoff, and more water directed back into aquifers.
More compact development leads to lower housing costs as lower land and infrastructure costs affect sales prices and taxes. Urban development means a different mix of housing types—fewer large single-family lots; more bungalows and townhomes—but in the end provides more housing choices for a more diverse population. It means less private space but more shared community places—more efficient and less expensive overall. Urbanism is more suited to an aging population, for whom driving and yard maintenance are a growing burden, and for working families seeking lower utility bills and less time spent commuting.
Urbanism leads to fewer miles driven, which then leads to less gas consumed and less dependence on foreign oil supplies, less air pollution, less carbon emissions. Fewer miles also leads to less congestion, lower emissions, lower road construction and maintenance costs, and fewer auto accidents. This then leads to lower health costs because of fewer accidents and cleaner air, which is reinforced by more walking, bicycling, and exercising, which in turn contributes to lower obesity rates. And more walking leads to more people on the streets, safer neighborhoods, and perhaps stronger communities.
The feedback loops go on. More urban development means more compact buildings— less energy needed to heat and cool, lower utility bills, less irrigation water, and, once again, less carbon in the atmosphere. This then leads to lower demands on electric utilities and fewer new power plants, which again results in less carbon and fewer costs. As Bucky Fuller exhorted us, urbanism is inherently "doing more with less." Or, as Mies van der Rohe famously asserted, "Less is more."
But for the past fifty years, our economy and society have been operating on the premise that "more is more" and "bigger is better": bigger homes, bigger yards, bigger cars with bigger engines, bigger budgets, bigger institutions, and, finally, bigger energy sources. In contrast, urbanism naturally tends toward a "small is beautiful" philosophy. This then involves trade-offs: less private space but perhaps a richer public realm; less private security but perhaps a safer community; less auto mobility but more convenient transit. Compact development does mean smaller yards, fewer cars, and less private space for some. On the other hand, it can dramatically reduce everyday costs and leave more time for family and community. The question is not which is right and which is wrong or that it must be all one way or the other—urbanism works best with blends. The question is how such trade-offs fit with our emerging demographics, our desires, our needs, our economic means—and perhaps our sense of what a good life really is.
Measuring and understanding the feedback loops and co-benefits of urbanism are critical to judging these trade-offs. Few comprehensive studies have brought all of these variables together, so we typically cannot understand the relationships and see all the implications. Fortunately, 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. 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. 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. 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. 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. 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. Less driving means less air pollution and less respiratory disease. More walking means healthier bodies and less obesity, affecting diabetes rates and all of its associated health costs.
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.
There is more. The efficient and compact buildings of urban development use less energy, produce fewer greenhouse gases, and cost less to operate. The carbon reduction in the building sector is projected to be over 62 percent less, not enough to achieve its share of the 12% Solution but a significant and necessary step. In total, the average household in the Green Urban future would save around $1,000 a year in utility payments. When this figure is combined with reduced auto ownership, maintenance, insurance, and gas costs, California households would save close to $11,000 a year in current dollars. With an interest rate of 5 percent in 2050, this could pay a mortgage of $200,000.
What is not to like in such a Green Urban future? For some, exactly the thing that makes most of these savings possible: a more urban life.