From an Online Discussion and Preserved

The chief problem of mankind is energy. Not in where we will get it, but in deciding what our consumption of it should be.

If it takes 300 units of "energy" to create me a stainless steel bowl that will last the rest of my life and can then be passed to my children to use for their lives, then that is a vastly superior usage of that energy to, for example, 30 units of "energy" spent creating a plastic bowl which will last two years.

The only sustainable human civilization was stone-age in technology. We have to consider that in our equations. It lasted for about 400,000 years, as best we can tell.

Agrarian civilizations then lasted for about 18,000 years before progressing to the industrial civilization which has only been around for perhaps 200 years.

I don't think anyone can look at the current industrial civilization and say that it can be sustained for another 200 years.

What we will have to develop then is either a post-industrial civilization, or revert to an earlier model which has proven to be more sustainable.