In recent years, as the world has become increasingly aware of global warming, an entire industry has grown up around the idea of trading carbon to help eliminate greenhouse gases, most notably CO2. As soon as developed nations began capping carbon emissions, driven primarily by the European Union (EU), a brisk global market for trading carbon developed. (Just last week, a carbon trading exchange, called the New Green Exchange, opened in New York.)

While the practice has its detractors, there’s certainly interest among businesses in high-polluting industrialized nations such as the United States to limit their carbon footprint — if not by polluting less, at least by buying carbon credits from countries that are lesser polluters, which is basically how the system works. But here’s the rub: Critics say rather than encouraging the world’s worst offenders to lower their emissions, carbon trading gives them license to buy their way out of a jam.

Pati Ruiz Corzo (left) is the director of the Sierra Gorda Biosphere Reserve.

This week’s Rough Cut isn’t about carbon trading per se. But it does show the potential for poorer developing countries to capitalize on a growing market by doing something as simple as planting more trees and protecting existing ones — and getting paid to do it. In 2007, in fact, the carbon trading market was worth $60 billion (up 80 percent from 2006), according to the research firm Point Carbon.

Jason Margolis, who first reported this story for PRI’s radio program The World, travels with producer Loren Mendell to the heart of rural Mexico to discover how a former schoolteacher is using carbon trading to revitalize an entire region.

Pati Ruiz Corzo is the director of the Sierra Gorda Biosphere Reserve, a protected area about the size of Rhode Island that is a five-hour drive north of Mexico City. When she left her teaching job in the city and moved to the region 25 years ago searching for a simpler life, she found the place littered with trash and stripped of much of its natural vegetation. She decided it would be her life’s work to restore the forest and to create new jobs for the people living in the biosphere.

“I’m a kind of stranger in the modern life,” she tells Margolis. “I’m free, I’m wild, I’m simple. I love to lie under a forest and have a nap and a snore like a wild boar. Here living with nature, I found the answers I was looking for.”

Recognizing Corzo’s commitment to the environment, the Mexican government declared the Sierra Gorda region a protected area 11 years ago.

Corzo’s efforts are beginning to transform the once-depleted landscape into a thriving habitat with fertile topsoil, a replenished water table and an abundance of newly planted vegetation. She’s also developing an eco-tourism industry with rustic lodge accommodations and craft shops for local artisans. It’s already a popular destination for birdwatchers. But Margolis also learns that many of the men in the community still head to the United States to find work, as they struggle to support their families off the local land.

Now with carbon trading a hot “commodity,” Corzo sees an opportunity to use her forest to raise money on the carbon market. Currently, she is working with nonprofits such as Earth Island Institute, based in the San Francisco Bay Area. The company lets individuals donate money to causes like Corzo’s to offset their own personal carbon footprint. These donations, made mostly online, help plant more trees and create sustainable jobs for the people living in Sierra Gorda.

Working with environmental business consultants, Corzo estimates that her forest is worth $1.1 billion on the carbon exchange. Down the road, she hopes that trading this carbon will provide enormous benefits for the bio-region she has nurtured.

Despite debate among scientists about how effective trees are in reducing carbon in the atmosphere — a lot depends on what types of trees are planted and where, and whether there’s some unforeseen slash-and-burn policy down the line — most experts agree that the growing appetite for trading carbon will help generate much-needed capital for greener energy solutions overall.

— Jackie Bennion

Mexico: The Business of Saving Trees is made possible by the Skoll Foundation through a grant to the PBS Foundation.

FRONTLINE/World Social Entrepreneurs
This story is part of our ongoing Social Entrepreneurs series, officially launched in 2006 to focus on individuals whose ideas are creating new and sustainable markets that benefit underserved communities in the developing world. You’ll find more stories in the series here.