J. B. Ruhl's dissertation defense in geography this past summer was an unusual affair. The student was a tenured professor, and his dissertation is already under contract with Island Press, a publisher of environmental books.

On the law faculty at SIUC from 1994 to 1999, and now at Florida State, Ruhl is a nationally recognized expert on environmental law and policy. His doctoral work focused on the economic benefits we gain from sustainable ecosystems, and how economic approaches are needed to preserve them.

Ecosystem "services," which range from pollination to climate regulation, have substantial economic value to society. But since those services don't appear on any ledger sheet, our laws and markets aren't geared to take them into account.

As Ruhl explains, we can estimate the value of the timber that a tract of forest could provide if it were logged. But we can't readily estimate the economic value of ecosystem services provided by an intact forest, such as erosion control, carbon dioxide absorption, and recreational value.

"People who own natural capital in the form of services—for example, wetlands providing flood control—can't benefit from it economically, so it's easier to make decisions to destroy it—for example, to fill the wetlands," Ruhl says. "If we can better account for the economic value of these resources, we can make better public and private decisions about how to use them."

Modernizing property rights, developing smarter regulations, offering economic incentives to keep land undeveloped, and changing social norms must all be part of the solution, he says.

As a law professor at SIUC, Ruhl began taking geography courses to gain a more comprehensive perspective on environmental issues. His dissertation makes the case that legal experts and policy makers need to work with geographers, ecologists, and economists to learn "what's happening on the landscape" and what the economic effects of environmental decisions are likely to be.

In many cases, he says, we simply don't have the data to know "what we're losing in terms of ecosystem services."

Take wetland mitigation. Federal law stipulates that if wetland acreage is destroyed for development, a comparable wetland must be created within a certain geographic radius. But to Ruhl's dismay, no agency had compiled data tracking the distances between destroyed wetlands and created wetlands.

After a lot of digging, he discovered that the wetlands being lost in coastal urban areas in Florida are being "mitigated" by wetlands miles away in rural areas. The urban areas "are losing wetland services that aren't being replaced," he says.

To remedy that, subsidies could be used to encourage near-site mitigation and taxes used to penalize far-distant mitigation. Or the regulations could be rewritten. In any event, says Ruhl, "Our decision making needs to be more complete."

Some positive changes are in the offing. The Army Corps of Engineers and the U.S. Forest Service say they will now consider ecosystem services in their projects and management plans.

The courts also seem more willing to take ecosystem services into consideration in property law. One judgment, for example, barred a private landowner from filling in a wetland. Why? The court held that the action would create a public nuisance by removing flood protection for the surrounding population.

And along the Florida Gulf Coast, Ruhl says, "land use planning has changed significantly" since recent hurricanes. That's a case of social values changing.

"Victims of Hurricane Katrina get it now," he says. "They are willing to pay for coastal wetlands protection, coastal dunes protection. If there's any silver lining to Katrina, it's that more people now grasp the importance of preserving ecosystem services.

"Will it translate into changes in common law vis-à-vis property rights? It could—especially if you argue plain old economic value to courts, rather than ethics."