The Tautology and Its Weaknesses

A given economic growth rate can be sustainable only if the average impact per unit wealth declines at an equal or greater rate.

I argue that this is certainly true if one grants that a sustainable behavior must be sustainable indefinitely.

Shortly after coming to this pretty firm conclusion and wondering how smug to feel about it, I realized that it’s just a consequence of the old I = PAT tautology, due to Ehrlich and Holdren (yes that Holdren). [more]