I would hope that there is a way to have an economic equilibrium that would allow change within the system–it would be a dynamic system, but not grow overall. I know that this sounds like pie-in-the-sky. On the other hand, the dangers caused by overall growth now appear real and dangerous to our way of life.

is nothing less than a call for an uprising that would reinvent modern capitalism and replace it with, well, a postmodern capitalism that values sustainability over growth, and doing good over making a quick buck. Sound idealistic? It is-but that’s part of the book’s appeal. Speth goes beyond finger-wagging to indict consumer capitalism itself for the rape and pillage of the natural world. His proximate concern is global warming and the impact it will have on civilized life as we know it . . .

GS: The fundamental thing that’s happened is that our efforts to clean up the environment are being overwhelmed by the sheer increase in the size of the economy. And there’s no reason to think that won’t continue. So we have to ask, what is it about our society that puts such an extraordinary premium on growth? Is it justified? Why is that growth so destructive? And what do we do about it?

Capitalism is a growth machine. What it really cares about is earning a profit and reinvesting a large share of that and growing continually. Profits can be enhanced if the companies are not paying for the cost of their environmental destruction-so they fight [paying it] tooth and nail. The companies themselves are now quite huge, quite powerful, quite global, and no longer just the main economic actors in our society. They are the main political actors also.

And so all of these things combine to produce a type of capitalism that really doesn’t care about the environment, and doesn’t really care about people much either. What it really cares about is profits and growth, and the rest is more or less incidental. And until we change that system, my conclusion is that it will continue to be fundamentally destructive.

http://www.commondreams.org/view/2008/10/19-5

For instance (a simple example, to be sure) if you have a zero growth, stable economy, you will not have any surplus. As long as nothing changes that might be fine, but what if your crops fail one, two, three years running? To feed your people, you’d have to “buy” grain or whatever from a neighbor. What will you buy it with if there is no surplus in your overall economy? And if the crops continue to fail and your workforce begins to diminish due to hunger and disease, then you quickly become a negative growth economy. Climbing out of that hole when nature turns things around can be a Sisyphean challenge.

The growth rate represents a buffer, which if absent renders your economy vulnerable to a kind of entropic decay.

That doesn’t even begin to take into account innovations which alter the needs-vs-desire cycle of the population.