Going from Seattle to London offers a pretty stark contrast in the possibilities of an urban future.
In Seattle, we're arguing about handling the future growth of our city, with some old-school pundits reeling at Mayor Nickels' suggestion that Seattle can make homes for another 350,000 residents, while many more move to new subdivisions on the fringe. His critics charge that a much more sensible plan would be to channel most of the estimated 1.6 million more people likely to live the Puget Sound area by 2040 outward, to "undeveloped rural areas."
Both plans are woefully out of tune with not just the needs of the future but of the realities of the present day. We already live in an age of peak oil worries, climate impacts and nature pushed to the limits. And the only way out of that dilemma involves ending sprawl and building cities that are far more intelligently dense than what we have today, No sustainable future can be built that doesn't rest on a foundation of smart growth.
Neither are these issues Seattle is alone in confronting. World population is currently predicted to hit roughly 9 billion by 2050 (PDF), while the U.S, can expect to see its population grow by at least 120 million (PDF) in the same period. Most of that growth will happen in our cities, so learning how to grow cities well is one of our most important jobs.
We already know that density is, of itself, more sustainable than sprawl. Compact mixes of shops, homes and workplaces use less energy, for starters, and produce fewer greenhouse gasses. Even where infrastructure is crumbling, having more users closer together means less cost and less ecological impact for everything from water to sewers to garbage collection. Sprawl, on the other hand, is environmentally costly, and destroys natural systems even at very low densities. In the 21st century, to live in a city is to be an environmentalist, and visa-versa.
The optimal density sweet spot for supporting sustainability is a matter of fierce debate, and no simple answer can be right. One certainly wants enough people in neighborhood cores to support public transit and a variety of shops. A minimum of 40 people per acre seems to be the threshold. When well-designed and lively, neighborhoods can be much denser and even more livable. They can even encourage people to give up their cars because life is easier without them (growing much healthier in the process).
That doesn't mean that the entire city need to be that dense, or that no place exists for homes with yards and trees. After all, one of the hallmarks of a successful city is kid-friendliness, and most every young family needs a little more space than the parents once did. Other folks need a bit of outdoor space to garden or relax in. A healthy city can be quite dense and accommodate a variety of lifestyles.
The trick seems to be recognizing that so-called "single-family neighborhoods" -- neighborhoods of homes with yards or courts -- can still be compact. Traditional families -- families with two parents and kids at home -- are, In fact, a small and declining percentage of families in the developed world. More and more, the people in a household have a variety of relationships (from relations to roommates to renters) and large single-family homes don't meet the realities of those new relationships.
All sorts of new possibilities, from clever duplex designs to "grandma flats" in basements and garages, allow older "single family" neighborhoods to offer homes to people in sufficient numbers to support transit and bicycle infrastructure, a variety of shops and decent services within a convenient walkshed.
Of course, some people quite like living at much higher densities, and Vancouver has shown that very high densities (by North American standards, at least) and a high quality of life can go hand in hand -- Sarah and I were just there last week, and we again found ourselves marveling at how new, how urban and how livable downtown Vancouver feels.
Much urban land is wasted: it sits unused as polluted brownfields, abandoned lots, unneeded parking strips. In any North American city today, there are numerous building sites which could support better use, and the tools are emerging to identify and develop those lots. Then, too, whole areas can be rezoned and redeveloped (as Vancouver did with its nearly-abandoned industrial lands, as San Francisco is planning and as Seattle could do with its South of Downtown and Interbay districts). These days, building a whole neighborhood from scratch can also offer the chance to build on a much more sustainable basis to begin with. And while new housing is more expensive, the location efficiencies of compact neighborhoods can make living there cheaper in the long run anyways. If we want to build bright green cities, we have to use all land well.
Between dense neighborhood cores, newly-repopulated single-family neighborhoods and new high-density neighborhoods, Seattle could accommodate many, many more people than it does today. Indeed, it would become a better city. A Seattle of 1.5 million or 2 million residents, properly designed and supported with the right systems, would be a better place to live.
London is the proof. London is incredibly dense, by American standards. Yet London is one of the best, most dynamic, most interesting and even comfortable cities in the world.
That's not to say that either city is perfect, or has it all right. Indeed, I think we are still developing a key component of this bright green urban future, which is an understanding of how to leverage what cities have to offer -- proximity, connectivity and experience -- to deliver a new more dynamic, greener way of life, to deliver the experiences and comfort we all aspire to at a fraction of the ecological cost.
This can be done. Over the next month, I'll be reporting from great projects in the field here in Europe, sharing my ideas on how we can reimagine urban life to be far more sustainable and far more livable than anything we have today.
