Reducing economics to simple calculations is what economists do for a living. The whole discipline, and much of our politics is based on that assumption. That's what Adam Smith and Karl Marx were all about.

The concept is not untenable, although whether this particular application is valid or not is another question. Personally, I believe its too late to do anything about global warming, not because its technically or environmentally impossible, but because it is politically and economically unmanageable. The short term sacrifices needed to deal with the long-term problem are simply not going to happen voluntarily. Too many people with too much power have too much to lose. The sacrifices will be involuntary, and much more painful.

Perhaps if we had started 30 or 40 years ago when the interrelated problems of resource exhaustion, overpopulation, and pollution were first identified as imminent, something might have been worked out and gradually implemented so it could have an effect over the long term . But now its too late, like the man says, doing anything effective about it is going to cause too much disruption and will generate too much resistance.

There is a positive side, though. What will probably happen is that the environment will change to the point where world agricultural, industrial and trade systems will be unable to adapt fast enough and start to fail, which will lead to economic and political conflict, and eventually war and social problems on a mass scale. This will stop the industrial/agricultural activity that started the problem to begin with, and the world will stabilize at some new level of population, production, consumption and civilization. How severe the change will be remains to be seen.

But we won't pick up where we left off. It will probably be similar to what happened in Europe after the fall of the Roman Empire, not a quick collapse into barbarism and chaos, but a severe but gradual decline to some new equilibrium. We will lose a few centuries, and the world which follows will not simply be a continuation of this one. We'll have to kiss space travel good-bye, for example, probably forever.

Incidentally, the fall of the Roman Empire is our most familiar model, but it is not the only one. China went through multiple collapses, as did the Indian subcontinent, so did the civilizations of central America and the Andes, and on a smaller scale in the eastern Mediterranean, and many times and places in the Middle East. We have plenty of precedents, although this one will probably be the first that involves the whole world, and the first that cannot be dealt with by simply going somewhere else and starting over.

The earth will certainly not become uninhabitable, it has endured much worse than Man, although it may be impossible to resume our current level of technology and civilization when all the easily accessible resources will have been pissed away supporting the west's extravagant lifestyle, a lifestyle the whole planet now feels it is entitled to. Depending on how much history survives us, I have a feeling our descendants will not remember us fondly.