For an interesting example of how property rights can turn environmental liabilities into profitable assets, check out To Save Wildlife, Namibia's Farmers Take Control by Christopher Joyce.
The NPR article documents how local ownership of wildlife resources has created an incentive for stewardship in the Namibian bush. In 1996 the Namibian government granted the right to manage and profit from wildlife to communal conservancies. Since then, the populations of rhino, cheetah, lion, and elephant have all rapidly increased, while the incidence of poaching has been nearly wiped out.
Driving this conservation success are revenues from tourism and hunting. As Joyce explains, the latter offends some wildlife protectionists (just read the comments below the article), but the results are hard to refute. Whereas wildlife populations are declining throughout most of Africa, they are flourishing in Namibia because "their fate (lies) in the hands of the people who share their lands."
*Thanks to Jamie Workman (PEI 2005) for spotting the article on NPR.