Penned in 1968, Garrett Hardin’s “The Tragedy of the Commons” surely overstated the case against the commons (“Commons Sense,” August 2, 2008), but his argument that all commons will be abused still pertains in many cases worth noting forty years later. In particular, commons that are too large and complex to be properly understood will surely be abused no matter how well they appear to be managed. In the case of climate change, the commons is the whole earth, as you point out. The trouble is that no-one on earth understands how the earth really works, and those who believe that they do understand the earth’s inner workings often disagree, sometimes violently. The commons that is the earth itself cannot be managed well, if at all. All attempts to manage it will remain risible. Overstretching the notion of commons to the earth as a whole cannot but end in tragicomedy.