Solar architect Steven Strong defines sustainability simply: the ability to keep on doing what we keep on doing. Yet how can we be sure that our actions and means are sustainable? In less than a lifetime, DDT has won a Nobel prize for its contribution to human health, and then been banished from our continent as a major environmental threat. Nuclear energy, which we learned in grade school would provide infinite, safe, cheap energy, now promises merely complexity and risk.

     After more than a century of global industrialization, scientists assent to three observations:

Sustainability appears to occupy the terrain bounded by three principles --

and three prohibitions --

     These ideas seem to be the perimeters within which every life form on the planet exists ...save one: us.

     No matter how completely our lives rely on industries based on extraction of fossil fuels, we must grapple with the fact that we are poisoning our planet. Industry's strategy -- heat, beat, and treat -- is primitive compared to the subtle energy-efficiency of photosynthesis. There can be no doubt that such primitive methods waste at least half the energy consumed; when we compare modern products -- a plastic container, for example -- with a more natural substitute -- a Pomo basket -- we might reckon that nine parts of energy out of every ten consumed are squandered while producing an inferior product. Surprisingly, this is good news. If we waste so much making drek, we need only attend to efficiency and quality in order to secure a good life within sustainability's perimeters.