In two celebrated and widely-anthologized articles, as well as several books, the biologist Garrett Hardin claims (a) that the world population problem has a certain structure – it is a tragedy of the commons - and, (b) that, given this structure, the only tenable solutions involve either coercion or immense human suffering. In this paper, I shall argue for two claims. First, Hardin’s arguments are deeply flawed. The population problem as he conceives it does not have the structure of a (...) commons; and even if it did, this would not necessitate the extreme responses he canvasses. Second, nevertheless, much of Hardin’s pessimism is justified. Some environmental problems associated with population do have tragic structures, though these are of a different form than Hardin envisions. For example, the problem of global climate change has an intergenerational aspect that makes it importantly worse than Hardin’s commons, and for this reason (as opposed to Hardin’s) extreme responses may be needed to avert environmental catastrophe. (shrink)