Those who take a keen interest in environmental issues will have come across many references that any more growth is no longer possible nor desirable.
Many believe that we are undermining the very life support systems that sustain us. Like bacteria in a petri dish, our exploding numbers are reaching the limits of a finite planet, with dire consequences. Disaster looms as humans exceed the earth’s natural carrying capacity. Clearly, this could not be sustainable. Many have learned the classic mathematics of population growth — that populations must have their limits and must ultimately reach a balance with their environments, it’s physics, after all, there is only one earth! "Carrying capacity" refers to the number of individuals who can be supported in a given area, within natural resource limits, and without degrading the natural, social, cultural, and economic environment for present and future generations. The carrying capacity for any given area is not fixed. Carrying capacity is not a fixed number. Estimates put Earth's carrying capacity at anywhere between 2 billion and even 40 billion people. It varies with a wide range of factors, most of them fitting under the umbrella of "lifestyle." If humans were still in the hunter-gatherer mode, Earth would have reached its capacity at about 100 million people. With humans producing food and living in high-rise buildings, that number increases significantly.
A good way to understand the flexibility of Earth's carrying capacity is to look at the difference between the projected capacities of 2 billion and 40 billion. Essentially, we're working with the same level of resources with both of those numbers. So how can the estimates swing so widely? Because people in different parts of the world are consuming different amounts of those resources. Basically, if everyone on Earth lived like a middle-class American, consuming roughly 3.3 times the subsistence level of food and about 250 times the subsistence level of clean water, the Earth could only support about 2 billion people. On the other hand, if everyone on the planet consumed only what he or she needed, 40 billion would be a feasible number. As it is, the people living in developed countries are consuming so much that the other approximate 75 percent of the population is left with barely what they need to get by. Ultimately, the idea is this: If everyone on Earth can manage to do more with less, we'll be back on track to Earth's indefinite carrying capacity.
The conditions that sustain humanity are not natural and never have been. Since prehistory, human populations have used technologies and engineered ecosystems to sustain populations well beyond the capabilities of unaltered “natural” ecosystems. We transform ecosystems to sustain ourselves. This is what we do and have always done. Our planet’s human-carrying capacity emerges from the capabilities of our social systems and our technologies more than from any environmental limits. The idea that humans must live within the natural environmental limits of our planet denies the realities of our entire history.
Charles Maurice and Charles W. Smithson at Texas A&M University studied the history of natural resources over 10,000 years. They found that temporary scarcities in natural resources are the norm. They also found that the same temporary scarcity always led to an improved substitute. The Greeks' transition from the Bronze Age to the Iron Age 3,000 years ago was forced by a shortage of tin. The rise of coal followed timber shortages in 16th-century Britain. The shortage of whale oil in 1850 led directly to the first oil well in 1859.
No comments:
Post a Comment