The Five Axioms of Sustainability

I found this via Monkeyfister, and I'm very impressed with the clarity with which Richard Heinberg lays out the five points of sustainable reality:
1. (Tainters Axiom) Any society that continues to use critical resources unsustainably will collapse.

Exception: A society can avoid collapse by finding replacement resources.

Limit to the exception: In a finite world, the number of possible replacements is also finite.

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2. (Bartlett’s Axiom): Population growth and/or growth in the rates of consumption of resources cannot be sustained.

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3. To be sustainable, the use of renewable resources must proceed at a rate that is less than or equal to the rate of natural replenishment.

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4. To be sustainable, the use of non-renewable resources must proceed at a rate that is declining, and the rate of decline must be greater than or equal to the rate of depletion.

The rate of depletion is defined as the amount being extracted and used during a specified time interval (usually a year) as a percentage of the amount left to extract.

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5. Sustainability requires that substances introduced into the environment from human activities be minimized and rendered harmless to biosphere functions.

In cases where pollution from the extraction and consumption of non-renewable resources that has proceeded at expanding rates for some time threatens the viability of ecosystems, reduction in the rates of extraction and consumption of those resources may need to occur at a rate greater than the rate of depletion.
OK, I realize that this is a much more serious post that any I have previously put up. But I do plan on writing more on alternative energy, a major interest of mine, in the future. This was the best short description of enviormental philosophy that I have read recently. Your thoughts? (that's what the comment function is FOR, people).