Yet another reason why: (1) I am less sanguine thinking about economics as a science today; (2) I do not assign textbooks in my environmental economics class.
Instead, ecologicals use phyical measures of ecosystem resilience and resource stocks weighed against population and consumption pressure as their measure of sustainability. Recall that from an ecological point of view, the only way to insure that future generations are not penalized by our actions is to hand down a stock of natural capital that resembles our own. This means, for example, on the global warming and ozone depletion fronts, our current impacts are not sustainable. This follows since everybody agrees that, unchecked, they will lead to large-scale changes in the global environment.
Wow. I added the bold at the end. So, now that is what we call science. “Everybody” agrees! Really, everybody? Every last person? Did the author survey them? Did the author read all of the scientific evidence first? I am actually on the side of the science indicating that a warming planet will cause changes – so I am not in denial about that. But it is not at all clear from my reading of the scientific evidence that everyone agrees that humans are causing warming. But even so, when is the last science book you read that reads something like, “Everyone agrees that the earth is the center of this universe?”
Second, this notion that we live sustainably only if tomorrow’s natural resource stock is the same as today’s is pure nonsense. First of all, manmade capital can and has substituted for natural stocks. Ecologicals do not accept this. So what do they mean? First, it MUST mean that no non-renewable resource can be touched by mankind … ever. How could they mean otherwise. But then we must say goodbye to metal, glass, ceramics, etc. None of the materials used to make those will be available to future generations – even if these materials are so abundant, that we could not use them up if we had all of human history to do it.
Further, what does it really mean to leave a stock of natural resources that resembles our own in a world when what is and is not a resource is, itself, changing from year to year?
