The world is going through a massive urbanization, overturning the traditional demographic order and challenging two millennia of literary and cultural concepts of the urban. In this last post, I want to return to the ecological impacts of that urbanization…and what conservationists can do to mitigate it.
The ecological implications of an increasingly urban world are in an important sense different than the demographic or metaphorical implications. In a world where humanity is overwhelmingly urban, our population dynamics or our cultural evolution will be mostly disconnected with what is happening in rural parts of the world. However, an urban world is still intensely linked with rural areas ecologically — we all need food.
During the long period of history where we were hunter-gatherers, humans had relatively little mastery of nature and the environment. Granted, our species was flexible enough to survive in many different environments, and we were skillful in extracting resources to feed ourselves.
One theory, the prehistoric overkill hypothesis, dates the extinction of many large mammals in North America to the arrival of human hunters. Still, many environmental changes were beyond our control. Most hunter-gatherers are only one or two bad seasons away from starvation, and average lifespan of different hunter-gather groups varied from 21 to 37 years. Compared to what was to come later, the degree of human mastery of the environment was low.
As the agricultural revolution occurred and cities began to be possible, human mastery of the environment expanded. One theme since the agricultural revolution has been a larger and larger percent of resources moving from rural areas to cities: Man was domesticating nature not just to feed farmers better, but to feed its growing cities.
This trend can perhaps best be seen with statistics on the amount of land was needed to support one person. Hunter-gather cultures in Mesopotamia could support less than one person per square kilometer. Agricultural productivity increased this more than 10-fold.
And agricultural productivity continued to increase over time. In the mid-18th century in Europe, one square kilometer of cropland might support 40-60 people. Currently, wheat farms using the best available technology might get 45 bushels from an acre, which is around 10 million calories per square kilometer — enough to feed 5,000 people per square kilometer.
This process of increased productivity, and the myriad other ways humanity has domesticated nature, has reached an astonishing scale. One estimate is that globally, humanity appropriates between 10% and 55% of all terrestrial biological productivity that exists on Earth.
As humanity moves into our first century, burgeoning urban populations will put increased demands on the environment. These increased needs will by necessity further increase our domestication of nature. Whatever wilderness that remains will either be because we can find no easy way to exploit it, or because urban dwellers want it to exist, as a playground or as a source of inspiration. The 96% of the Earth’s surface not in cities will increasingly be shaped by the wants of urban dwellers, many of whom may know little about it. The rural world will become the urbanites dream of what the rural should be.
So, how do you do conservation in an urbanizing world?
Encouraging greater efficiency: First, anything that makes cities more efficient — in terms of resources or energy — will lessen the impact of urban dwellers on the broader world. These kinds of efficiency considerations are not the kind of thing that conservation organizations, used to thinking about diversity in mostly rural landscapes, usually put much time into. But in an urbanizing world these considerations become much more important, because much of what is happening in rural places is because of demand by urban dwellers.
Climate change highlights this importance, because how the next great cities of Asia and Africa are built and where they get their energy will in large part determine how bad climate change gets and how much biodiversity we lose. For example, how much the average Chinese (or American) citizen drives, and how fuel efficient their car is, matters a great deal to the ecological viability of every Nature Conservancy preserve on Earth.
Cultivating a conservation ethic. Second, and probably more important, conservationists need to make sure that the next great cities of Asia and Africa are full of people who care about the environment and want to protect the wild spaces that are left.
Several people have pushed me for specific ideas on how to reach out to urban dwellers, and I don’t have any brilliant new ideas. My reading of history in the United States and Europe is that two key things are needed to make sure urban dwellers are dedicated conservationists:
- Environmental movements that affect life in the city and make it better, whether it’s neighborhood parks or clean water; and
- Close contact with wild natural places at some point in their lives.
And there’s every indication that both those things will be needed to continue to have support for conservation in an urbanizing world.
(Image: Kestrel in Melbourne, Australia. Image credit: mugley/Flickr through a Creative Commons license.)