Cities are the greatest hope for our planet
If we design cities like ecosystems, they would have the potential to address many of our most pressing issues.
This story first appeared at Ensia.
Of all the things people build, cities are the most important.
Cities are the largest things we build, and most people live in them. But that’s not why cities are our most important invention.
Cities matter because they represent our greatest hope for long-term survival, not only for humans but for all species. They offer the best chance to dramatically reduce carbon pollution, provide shelter and community for the world’s growing human population and protect rural habitat for species in decline.
But to make this hope a reality, we must recognize that cities — and people — are part of nature and subject to the same laws as the rest of nature.
For too long we have ignored the relationships between built and natural environments. Economic development has focused on “taming the wilderness” with technology. And while the “wilderness” is strikingly diverse, urban technology has been disturbingly monocultural.
Consider an example: Minneapolis and Phoenix are in very different biomes. Mother Nature wisely recognizes the differences, putting different plants and animals in place in different climates. There was a time when humans recognized the differences, too. Homes in the American Midwest once sported good insulation for the winter and screened “sleeping porches” for the summer. In the Southwest, thick adobe walls kept dwellings cool during the day, and heat stored in the walls served as a thermal flywheel to keep the homes warm at night.
In his new book, "Let It Shine," John Perlin traces passive solar design to Neolithic Chinese more than 6,000 years ago. Well into the 20th century, office buildings in Buffalo, N.Y., did not look at all like offices in Los Angeles.
Such designing with nature was lost with the advent of cheap, abundant fossil fuels. Humans began constructing the same buildings everywhere. The most prestigious design prizes today are awarded for sculptural elegance without regard to local conditions or functionality.
Civilization is natural
However, the tide may be turning. Recently, astrophysicist Adam Frank asked on National Public Radio, “Is civilization natural?” His answer: Absolutely. Cities depend on the same natural laws as everything else. And now that we’ve entered the Anthropocene — an era where humans are the leading driver of change on a planetary scale — distinctions between human civilization and nature need to be rethought.
At a very small scale, a civic organization in Seattle has begun creating “pollinator pathways” by carefully choosing and planting native plants to ensure that pollinators can move over broad areas. At a macro scale, many cities built along rivers have begun to restore them to recover the invaluable services they once provided, instead of continuing the tradition of transforming them into industrial dumps and toxic shipping lanes.
From Louisiana’s disappearing coastal wetlands (which once buffered New Orleans) to Manhattan’s Lower East Side (recently inundated by Hurricane Sandy), people are waking up to the fact that cities are composed of human technology (buildings, roads, sewers, power lines) intermingled with ecological systems (streams, wetlands, trees, wildlife.)
Incorporating lessons from the natural world into human technology is not new. Since before Leonardo da Vinci studied birds to inform his sketches of “flying machines,” people have looked to nature for inspiration and guidance. But it was not until 1997, when Janine Benyus released "Biomimicry: Innovation Inspired by Nature," that a movement was born.
On her website, Benyus describes biomimicry as “learning to live gracefully on this planet by consciously emulating life’s genius. It’s not really technology or biology; it’s the technology of biology. It’s making a fiber like a spider, or lassoing the sun’s energy like a leaf.”
In the Anthropocene, it is well past time for us to learn to “emulate life’s genius.”
Cities as natural ecosystems
So how can we design our cities like ecosystems? The answers are all around us.
Solar panels convert sunbeams into electricity. Operable windows act like pores, opening and closing to maintain a comfortable temperature inside. Green roofs filter rainwater like soil. Cisterns mitigate stormwater runoff like small ponds and wetlands. Walkable neighborhoods follow nature’s most important design principle, the conservation of energy.
These simple examples represent the first tentative beginnings of a profound change in the way Americans design and build cities. Yet they are commonplace in Copenhagen, Freiburg, Barcelona and Singapore.
A recent study conducted by Autopoiesis LLC and Ecotrust and funded by the Bullitt Foundation shows that if we mimic nature, we also can generate significant public benefits. The report, Optimizing Urban Ecosystem Services: The Bullitt Center Case Study, found that over the life of the building, “just six of the [Bullitt Center’s] green features will produce up to $18.5 million in benefits to society” — storing carbon, managing stormwater and treating sewage, for example. Coincidentally, that’s about the same as the total construction cost for the project.
Comprehensive studies of the value of ecosystem services have been done at vastly larger levels, typically national or global. These studies have repeatedly produced shocking results, such as that the value of the planet’s ecosystem services is greater than the total monetized value of the entire world's GNP (PDF). But studies at such broad scales necessarily involve some heroic estimates and large error boundaries. The Bullitt Center case study is the first and only such research at the level of an individual building, with assumptions clearly laid out.
Obviously, much important research remains, but it is already clear that the value of public benefits is too great to be dismissed in a footnote as “externalities.” Design firms such as HOK and Arup (PDF) have begun designing buildings and towns — many in China — around ecological principles. And American cities from Seattle to New York are starting to incorporate the public benefits of natural systems into urban planning.
In the Anthropocene, it’s time to stop thinking of people as separate and distinct from “the environment.” We eat the environment. We drink the environment. We are an integral part of the environment. When we realize that all life is part of one big system, we open our cities to lessons nature has been beta testing for billions of years. And in that notion lies the greatest hope for our planet.