How many acres of land does it take to support one human being? How much crop and pasture land is required to grow that person's food? How much forest is needed to provide oxygen, clean air and water as well as paper and building materials? How many acres of land does it take to absorb an individual's wastes?
As this planet's population of human beings keeps rising, and our per capita use of the environment also increases, these are vital questions.
Obviously, the answers depend on the person's lifestyle. A Chinese peasant farmer who lives on the equivalent of $80 a year needs less land than a globe-trotting businessman with two homes and three cars, who squeaks by on a quarter of a million dollars annually.
In their recent book Our Ecological Footprint: Reducing Human Impact on the Earth, community and regional planners, Mathis Wackernagel and William Rees calculated just how much land North Americans require. On average, each of us needs between 10 and 12 acres of ecologically-productive land to provide for our consumption.
With the Earth's current population, however, there are fewer than 4 acres of this land per person. There's a serious problem here.
If everyone in the world used resources the way North Americans do, we would need two to three additional planets as large and as bountiful as this one just in order to supply the needs of those who are alive now.
Yet, the Earth's population grows by nearly 100 million people each year. And, all over the planet, productive ecosystems and farms are being converted into subdivisions, parking lots, industrial parks, shopping malls and highways - all ecological wastelands. Meanwhile, the global communications juggernaut tries to convince Chinese farmers and all those with tiny ecological footprints, to adopt the automobile, fast and processed food, air conditioning, aluminum can and hamburger habits which make our ecological footprints so enormous.
If we first recognize our connections to the land, and then how much land those connections require, we might actually be able to create a more sustainable future.
It's easy to appreciate the need for land to grow trees, grains and other foods, and to graze animals. Yet these uses account for just a part of the land that we require. More than half, or about six acres per North American, is necessary to absorb the carbon dioxide released by our fossil fuel consumption, assuming that atmospheric stability (to minimize climate change) is our goal.
Burning fossil fuels in power plants, vehicles and factories releases their stored carbon as CO2. If this carbon dioxide isn't absorbed by green plants or by the shell-forming organisms in tidal zones, it accumulates in the atmosphere, where it has the potential to effect changes in the earth's climate.
If population and consumption keep growing as expected, by the middle of the 21st century we will need six to twelve more planets as large and as bountiful as this one in order to prevent rapid deterioration of the environment.
But, since we are not likely to find even one more well-stocked planet any time soon, what else can we do?
A simple answer, which is contrary to the major thrust of our culture, is to consume less, and produce more of what we need ourselves, close to or at home. Food produced in nearby organic gardens uses much less land than food grown thousands of miles away which has to be processed, packaged, frozen, warehoused and shipped before it is at all useful to our bodies.
Simple things like staying home, eating fewer animal products, drinking tap water instead of packaged beverages, composting biodegradable wastes, using a clothes line and planting trees are powerful antidotes to the rush toward greater consumption and the huge ecological footprint that it produces.
The more we disconnect from the consumer culture and reconnect with our local ecosystem, the better our chances are of finding a way to live sustainably on this beautiful planet, the only one we've got.
This is Bill Duesing, Living on the Earth
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