Unformatted text preview: mental capital.
As a global society, our current lifestyle is clearly unsustainable. The Earth’s population will increase from six
to nine billion by 2050, yet we are already pushing the limits of our resources. Humans use over half the
accessible water and about 40% of the energy from the sun captured by plants through photosynthesis. We
have created a large hole in the ozone layer and increased the concentration of carbon dioxide in the
atmosphere by more than a third in the last 175 years. The rate of species extinctions is growing exponentially;
we are in the midst of earth's sixth mass extinction event, one primarily caused by humans. We have fully
exploited nearly 80 percent of our fisheries. Clearly, we cannot afford to double human population from six to
Many people think that the earth has a limitless capacity to meet our resource needs and absorb the
waste that we produce. However, the global population – and particularly the U.S. population - is currently in
18 1/20/2011 Chapter One: Principles
ecological overshoot: we h...
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- Fall '14
- John C. Ayers