Introduction: By Paul Hawken

For most of the 19th and 20th century, cities, despite the hardships and suffering experienced in ghettos, were seen as places where culture and intelligence concentrated and evolved. In the latter part of the 20th century, urban decay, environmental problems, and ethnic riots created a rush for the exits and rampant urban sprawl. Cities became more dangerous and inhuman. Post-war modernist planners and architects made matters worse by creating concrete monuments to themselves, hollowing out downtowns into commercial centers that felt like mausoleums at night.

Nevertheless, cities grew exponentially, another negative because of environmental impacts. When Paul Ehrlich published The Population Bomb in 1968 he wrote that:

"A cancer is an uncontrolled multiplication of cells; the population explosion is an uncontrolled multiplication of people. Treating only the symptoms of cancer may make the victim more comfortable at first, but eventually he dies – often horribly….we must shift our efforts from treatment of the symptoms to the cutting out of the cancer. The operation will demand many apparently brutal and heartless decisions. The pain may be intense. But the disease is so far advanced that only with radical surgery does the patient have a chance of survival."

Ehrlich predicted England would cease to exist by the end of the 20th century and India would have collapsed while mass starvation swept the globe. It seemed that by the 1970s, no one had anything kind to say about cities. Then, something happened that no one predicted.

Birth rates steadily declined and are still declining. In the developed world, they average 1.6 children per woman. In the developing world, the rate is 3 per woman. In countries such as Japan , authorities even ask women to have more children. Given existing trends, population will peak sometime at or before the middle of the 21st century, and then will begin to draw down for decades, possibly leveling out at 2 billion late in the next century.

One of the reasons population rates continue to drop is because of cities. A contributing factor to birth control in the world is the urban environment. Population planning is an individual act, but the incentive to plan a family is heavily influenced by urban migration. People are leaving rural areas where children are an asset, and relocating in cities where too many children are a liability. In the country, the emphasis is on work, and children provide ready assistance. In the city, the path to a better future rests in having fewer children, who are well educated. Virtually all of the increase in world population that will occur in the next 40 or 50 years will occur in urban areas. For example, in 2004 world population increased 76 million: 3 million was in the industrialized world, whereas 73 million was in the developing nations. In that same year, the urban population increased by 64 million.

Two hundred years ago urban population was around 3 percent, one hundred years ago it was 14%, and by 1950, close to 30%. According to the UN, in 2030, 61% of people will live in urban areas and the rural population in 2030 will be smaller than it was in 1995. Every week, over one million people are leaving the country and moving to the city.

Urban migration represents a kind of collective wisdom, and how we configure our cities will be critical to our survival. Regardless of the myths about living close to the land, cities are where human beings have the lowest ecological footprint. It takes less energy, wood, material, and food to provide a good life for a person in a city than in the country. Rather than perceive the city as an ecological sink sucking up the resources of the countryside, which cities can do, cities can also be a kind of ecological ark, places where humanity gathers while we peak in population and develop ecological intelligence for a new civilization. There is wisdom in this that is rather extraordinary. It was not predicted that cities might be the best strategy for our long-term survival and well-being. Yet that is exactly what is happening.

The viability of the urban environments, however, is not a given. Population is still increasing, demand on resources is growing faster than the population, and our climate, oceans, and ecosystems are perilously close to disaster. In other words, while we grow we must use less resources. We must build urban arks that are equipped to navigate the uncertainties and demands of the coming decades; cities have to be redesigned, reimagined, and reconsidered. The sustainable city is a place that interacts with its region and resources in a symbiotic way so as to increase the quality of both environments.

The SustainLane US City Rankings is the first systematic report card measuring city quality of life combined with resource impacts. For too long, we believed that more meant better, that energy-, concrete-, and automobile-intensive cities would bring us a better life. That tall tale is being replaced by common sense understanding that what makes for a fulfilling urban existence is neighborhoods, farmer’s markets, parks, mobility, quiet, greenery, and meaningful livelihoods, all of which require less resources and better design.

Urban sustainability is not an option. It represents prudent governance and provident management by and for the people. A carbon-constrained world is upon us. While international action is required to prevent global climatic catastrophe, cities must lead the way in creating a post carbon environment where people can thrive. What we do in the United States and other developed nations can help far-away cities. Our level of consumption and its attendant wastefulness has set an unfortunate example the world strives to emulate. Now we must set a different example because how people live in India and China will have a direct effect upon our children’s futures and vice versa. The upper stratosphere has no national boundaries; nor do jet streams and climate. By creating cities that address the future bravely, brilliantly, and humanely, we create examples and possibility for all cities everywhere.

The worldwide diaspora of immigrants, refugees, and peasants to urban slums is growing. The World Bank has predicted that more than five billion people will be receiving less than $2/day by 2030 in today’s dollars. The future of the world is being cultivated in the despair, anger and bleakness in the chawls of Mumbai, the favelas of Rio, in the kampungs of Jakarta , the shammasas of Khartoum , in the pueblos jovenes in Lima , and in the umjundolos of Durban . In Darwinian terms, the slums and squatter cities are a rapid breeding pool for human evolution. Leaders, activists, and scholars will emerge from these places, but so too will demagogues, jihadists, thieves, and mobs. That famous lyric “Freedom is just another word for nothing left to lose” may be true for seekers and monks, but it is not true for the bulk of humanity. Freedom and the rule of law are valued and honored when people have something to lose. Neighborhoods work, and are safe and livable because there is a “we” there. The greening of the world’s cities is a profound act of social healing and justice, because sustainability addresses whether people feel hope or despair, are secure or threatened, want to cooperate or compete.

I believe the SustainLane methodology will become international, and none too soon. Providing and analyzing the metrics for sustainability is critical to humanity’s future. In the end, there is only one ark, the earth. Cities, like individuals, are passengers on this miracle. All cities must work together in this green and just enterprise to insure that the journey continues. I believe SustainLane’s work reflected in this website is a critical tool in that pursuit.

The above was excerpted from SustainLane's 2007 Book: How Green Is Your City?, The SustainLane US City Rankings, published by New Society Publishers.