A word with many meanings:
Sustainability is about living within our means. The Earth has a finite number of resources, and we need to use them in a responsible manner to ensure the security of future generations.
Sustainability is about working with the Earth. An important part of sustainability is developing technologies that work with the Earth’s natural processes. Renewable energy sources are just one example.
Sustainability is about respect. Respect for the environment, respect for other living things, and respect for yourself. An understanding of the interconnected nature of our world helps to illustrate how what one does to the environment affects each individual.
"Then I say the earth belongs to each generation during its course, fully and in its own right. The second generation receives it clear of the debts and encumbrances, the third of the second, and so on. For if the first could charge it with a debt, then the earth would belong to the dead and not to the living generation. Then, no generation can contract debts greater than may be paid during the course of its own existence."
-Thomas Jefferson, Sept. 6, 1789