MONDAY, June 24, 2002 (HealthDayNews) -- Like the houseguest who raided the refrigerator and refused to restock it, humans are depleting the Earth's resources faster than the planet can replenish itself.
A new study says that in 1999, the human economy overshot available ecological resources by 20 percent, meaning it would require 1.2 Earths to regenerate what humans consumed that year. The research appears in tomorrow's issue of the Proceedings of the National Academy of Sciences.
Previous studies have calculated use of individual elements, such as forests and carbon dioxide, but this is the first time a larger accounting picture has come into focus.
"It's like borrowing. That's why we need these accounts," says Mathis Wackernagel, study author and program director at Redefining Progress, a nonprofit public policy organization in Oakland, Calif. "What we don't measure we don't see; so now basically we rip up our receipts and say 'great,' but the debt is not going away. It's like a business that doesn't have an accounting department."
And this "business" is saddled with other bad news. Last week's issue of Science ran a study finding that global warming will likely mean an increase in infectious diseases.
"We're certainly using more than our share," says Dr. Paul Epstein, associate director of the Center for Health and the Global Environment at Harvard Medical School in Boston. "We're using too much and generating waste, and this is when most organisms level off their growth rates. We have not been able to do that. This is the crux of the matter."
Wackernagel and his colleagues compared humanity's demand on the environment to the earth's bioproductive capacity over the past 40 years. The researchers looked at the amount of land used for growing crops and grazing animals; the harvesting of timber; marine fishing; and the effects of using fossil fuels.
They found that in 1961, human demand was about 70 percent of Earth's regenerative capacity. By the mid-1970s, demand was equaling supply and, by the 1980s, demand was exceeding supply.
Although the study doesn't document how long humans have before ecological assets run out, the planet's resources are finite and our current rate of consumption is simply not sustainable indefinitely. "The problem is that overuse can lead to destruction of assets," Wackernagel says. "If you use up the capital, it doesn't produce interest. It doesn't necessarily come back on its own."
However, people can still make choices that would avert ecological bankruptcy. Wackernagel says people could reduce fertility rates, and also use resources more efficiently. "There are actually ways to improve quality of life by controlling our consumption, because now consumption runs into rat races," he says.
The findings point up the need to explore different models of development. "One can hope that this will make us question our form of development and the way we're using resources for energy," Epstein says. "It's very clear that equity is an issue for development and for leveling off population growth. While we don't have to give up all of what we're doing, we do have to think about how to make trade and development and share of resources more equitable."
Wackernagel points out the timing of the article couldn't be better -- just before the United Nations' World Summit on Sustainable Development in Johannesburg, South Africa, at the end of the summer.
"If we choose, we can turn it around," Wackernagel says. "And here's a tool to track it."
What To Do
For more information on sustainability, visit Redefining Progress.
To find out how much you are consuming as an individual, check out Ecological Footprint.
Here is the Web site for the upcoming World Summit on Sustainable Development.
