It annoys me when intelligent people don’t do their research. In his recent letter to investors, Jeremy Grantham says:

Damage to the “commons,” known as “externalities” has been discussed for decades, although the most threatening one – loss of our collective ability to feed ourselves, through erosion and fertilizer depletion – has received little or no attention. There have been no useful tricks proposed, however, for how we will collectively impose sensible, survivable, long-term policies over problems of the “commons.”

This is total bunk. This ‘useful trick’ has been around for at least 50 years.