The Oil Drum

Jared Diamond touches on this in Collapse.  He says either "grassroots" or a strong central government works.  The size of the society determines which method works.  "Grassroots" works only in very small societies.  Basically, they must be small enough that everyone can understand all the problems they face.  And small enough that everyone has a "stake" in the preserving the commons.  

Larger societies need central control.  Perhaps a king whose advisors can keep tabs on the entire kingdom, so he can see the big picture even though his subjects cannot.  The king derives his wealth from the entire kingdom, and wants his heirs to do the same, so it's in his interest to protect the whole kingdom.  

Neither system works for middle-sized societies (and possibly large societies with weak central control).  If the society is not large enough to support a central government, but too large for everyone to have a stake in everything, it collapses in internecine fighting.    

It's worrying, because it suggests there might be some issues with democracy as a method of government.  An elected leader may not have the same incentive to protect the entire nation that a king has, since his time in office is limited.  In theory, that might encourage looting the nation while you can. In practice, we've seen it happen exactly that way, time and again.  

And with our level of technology, the "society" must be global if we hope to protect the commons.  Limiting our emissions will do little good if China decides to burn all the cheap coal they can get ahold of.  A nuclear war that breaks out in the Middle East could rain radiation on the entire world, or worse.

I think Newman is right.  Capitalism is a great system for quickly exploiting natural resources, but it won't work in resource-limited world.

Damned if I know what will, though.