How to Get Wall Street to Hug a Tree

Gretchen Daily, an ecologist at Stanford University, wears butterfly-patterned socks. She's a careful recycler and bikes to work. She composts.

So what's she doing hanging out with guys from Goldman Sachs?

As a tried-and-true "green," she believes she doesn't have a choice.

"Time is running short," she says. "Appealing to moral sense isn't enough anymore. We have to make conservation fit mainstream business calculations."

In her fourth-floor office in the Herrin Labs just off Stanford's main quad, Daily, a professor of biological sciences and director of the tropical research program at Stanford's Center of Conservation Biology, shows me what she means. She clicks open a series of digital maps compiled for a meeting in New York with Goldman Sachs. The maps' rich purple-and-blue hues convey information about California's Central Coast eco-region, which stretches from Santa Barbara north to Napa County and includes San Francisco Bay. Daily explains how each image tells a story of the terrain's value--not property value as a real estate agent would figure it but value in terms of service to mankind. Where the terrain offers a high degree of flood protection, for example, the map is the brightest purple; where the flood-protecting function is comparatively low, the color is light blue. The ecosystems providing the most overall value to people are shaded to indicate highest priority.

If Daily and her colleagues can get Wall Street on board, the maps will also be shaded to indicate financial worth.

This is the future of the environmental movement. Increasingly, economic measures are being used to assess ecosystems by way of the universally comprehensible currency of money. The calculations can be quite explicit: A recent study by the World Wildlife Fund reckoned that the bees that pollinate a Costa Rican coffee farmer's crop, and by extension the nearby forest where the bees live, are worth as much as $60,000 annually to the farmer. Last year, two entomologists, one from Cornell University and the other from the Xerces Society for Invertebrate Conservation, figured that a $60-billion-a-year chunk of the U.S. economy is supported by wild bugs such as dung beetles and bees that pollinate plants, hasten the decomposition of manure, feed on crop pests and end up as dinner for birds, small mammals and fish.

Such huge numbers can be compelling, and they get people talking. Which is the point.