The Living City By William McDonough 居住的城市(3)

hardware and software of the 21st century. These flows of nutrients are the twin metabolisms of the living city. If we are to make our cities truly sustaining we need to take this literally, not just as the beautiful and moving idea about cities that Levi-Strauss blessed us with, but as a literal, strategic truth that informs all of our designs.

What might this look like? What might Chicago be in 2020?

Nutrient Flows: A New Relationship Between City and Region

One thing seems clear about the future of Chicago: it will be, as it has always been, a regional hub. But what kind of hub? Cronon explains in his history of Chicago, Nature's Metropolis, how the city's grain, meat, and timber markets transformed the landscape of the West. Railroads, grain elevators, stockyards, and wheat farms stretching from Illinois to the Rocky Mountains all emerged in relation to Chicago's markets. All of these "landscapes of production" created a "gritty web of material connections" that fed, clothed, and sheltered the people of Chicago and its hinterland. But not without cost. The harvest of commodities from the woods and prairies, and their processing in the city, created degraded landscapes on both ends of the rails that carried nature to market. As we saw in the floods of 1998, the Great Plains are dramatically losing their ability to hold water and the great flush of toxins has created a 100 square mile area of the Gulf of Mexico known by scientists as the Dead Zone. There are other, more positive ways in which Chicago might be a hub. What if Chicago became a different sort of "Nature's Metropolis," a city bound to its region by healthy, reciprocal relationships in which nutrition flowed both

ways? From the countryside would come biological nutrition and from the city, technical nutrition.

Supporting a regional organic food system would be a good place to start. In this new model, Chicago's markets could support the rebirth of the American prairie. Organic farming works with natural cycles of water and natural flows of nutrients. By returning the carboniferous material to the soil it heals the land and the watershed, a dire need in a region in which conventional farming is exhausting the earth. As Chicago's markets for organic food grow, the city would become an ever-stronger catalyst for the restoration of economic, social and environmental health in the rural Midwest-not to mention the health of Chicago's citizens.

In a similar way, Chicago's status as a hub city could make it the Midwest

capital of green manufacturing and transit, energy effectiveness, and

cradle-to-cradle recycling. Following principles derived from nature's laws provides the framework for developing these new systems.

Consider again Waste=Food. When industrial and architectural systems are modeled on the earth's perpetual flows of energy and nutrients, human productivity can be positive and vital. The biodegradable and infinitely

recyclable textiles I've mentioned are just the beginning. We are also working with industrial designers to develop materials, products, supply chains and manufacturing processes that replace industry's cradle-to-grave

manufacturing model-the one-way trip to the landfill-with cradle-to-cradle systems. In cradle-to-cradle systems, products are conceived with safe,

healthy materials, which are managed within closed-loop cycles. The materials go back to soils safely, or they go back to industry. Every material is either a biological nutrient or a technical nutrient. No waste. No pollution. Just two discrete regenerative metabolisms feeding the urban organism. If Chicago's industrial sector re-invents itself using a cradle-to-cradle model, the nation's hub of green manufacturing and resource recovery may well turn out to be on the shores of Lake Michigan.

Using energy effectively will also support the living city. Along with Chicago's strong commitment to developing solar and wind power, the City is also

building three libraries and a police station using LEED standards (Leadership in Energy and Environmental Design) and spending more than $100 million to make existing city buildings more energy efficient and providing grants and incentives for others to do the same. The use of renewable energy sources, already stimulating the emergence of green technology in Chicago, could further charge the growth of new industries, such as the manufacture of wind turbines. Indeed, Chicago could jumpstart the entire wind industry and

become known as "the city that makes wind turbines for the world." This could supercede traditional coal generated energy and simultaneously begin to

power Chicago's transit system. Going to work? Ride the wind. It's not so far fetched; in Calgary the subway is partially powered by prairie winds. Gives a whole new meaning to "Windy City."

With these pieces in place, we can begin to see Chicago's metabolism rendered visible. We can imagine the flow of biological and technical nutrition between city and hinterland in an entirely different landscape of "material connections." The ecologically connected city receives food, water and energy from a very broad nexus of solar-powered, biologically-based, photosynthetic systems. The energy of the sun is harvested on rooftops; rural windmills power city buildings; water falls on hard urban surfaces but also on rooftop gardens and a connected network of green spaces, and it all flows safely into the ground,

into the watershed, into the air. In the countryside, farmers grow good food using implements manufactured in the city-technical nutrients-and the city, a visceral, breathing body, receives its nourishment from the hinterlands,

digests it and then excretes it back to its source, returning biological nutrients to replenish the rural soil. The windmills on the farm, source of a new cash crop, are forged in the city, produce power for the region in the countryside, and then are returned to the city every 20 years to be refurbished and

returned to the farm. Everything moves in regenerative cycles, from city to country, country to city, all the polymers, metals, synthetic fibers and

communications software flowing safely in the technical metabolism, all the photosynthetic nutrients flowing in the biological metabolism. The organic and the esthetic bring the city to life.

Creating Community Wealth

This vision comes home in Chicago's neighborhoods. Clean, vital industry; energy effectiveness; safe, affordable housing; and good mobility systems provide the infrastructure and the wherewithal for strong community life. They are the basics that no one should be without.

Why not go beyond the basics? The neighborhood, with the street as its

lifeblood, is perhaps where economic, social and environmental concerns mix it up most strongly. For us, that signals opportunity. Areas in urban communities where commerce, patterns of travel, and opportunities for

sociability bring people together respond eagerly to attention. They are ripe for "community seeds."

A community seed might be as simple as a laundromat, which can be much more than a place where one's clothes are washed. Imagine, for example, a laundromat on a busy neighborhood street that shares a public courtyard with a daycare center. The laundry is run by a small group of retirees and it serves an older clientele too. The machines are manufactured for disassembly and reuse and are powered cost-effectively by the sun and the wind. The wash water is purified in a botanical garden in the courtyard, where children and their parents mingle with elderly people as they wait for their clothes to dry. The garden's flowering plants brighten what turns out to be a local transit hub. It's not a flashy place, but it's a viable business that provides needed services while bringing the generations together in pleasant surroundings. Places such as these can be important centers of neighborhood life.

Natural areas are important to city neighborhoods too. Developing a plan for a local park can build strong community ties and, once realized, green spaces provide opportunities to relax and reflect among the trees and flowers, a needed respite from active streets. Along with planting trees city-wide,