A little over a decade ago, the major players in the environmental movement tried to take on Florida's sugar producers. The industry's fertilizers were polluting the Everglades, and the environmentalists asked Florida voters to approve a penny-per-pound tax on sugar companies that would yield $35 million a year for cleanup work.

But "Big Sugar" responded with a multimillion-dollar campaign to portray the environmentalists as white elitists attempting to weaken an industry that employed blacks and Latinos. Jesse Jackson joined forces with the industry, telling Floridians, "We should never have a showdown between alligators and people." With the help of minority group blocs, voters soundly rejected the tax.

Slideshow: More than a dozen "environmental justice" projects in action

The defeat was a wake-up call for the National Audubon Society, The Nature Conservancy and other large environmental groups, which at the time were staffed and supported mostly by white people. In recent years, these organizations have begun to devote a great deal of money and effort to engage minority groups—not just to foster a sense of inclusiveness, but to survive in a demographically changing society. Nonwhite people make up 33 percent of the U.S. population, and the Census Bureau expects that figure to increase to 50 percent by 2042. Meanwhile, a survey of 60 environmental groups conducted in 2002 found that minorities made up less than 13 percent of their staffs.

Whites don't have greener sensibilities than nonwhites. Rather, many minority environmentalists have declined to join the large environmental organizations because they think the organizations focus too much on wilderness preservation and not enough on public health issues such as toxic dumping and lead poisoningproblems that disproportionately affect minorities and poor people. In the 1990s some of these minority activists formed parallel campaigns—the "environmental justice" movement—that consists mostly of small, community-based organizations.

Today, the large national organizations are trying to bridge the divide between the two crusades. Audubon has undertaken an ambitious, nationwide effort to turn blighted sections of inner cities into nature education centers. They offer after-school programs, summer camps and internships to children who will—if the plan succeeds—grow up to be environmentalists and, perhaps, Audubon staff and members. In the past two years, such centers have opened in Dallas, San Antonio and Seattle, and two more are scheduled to open this summer in Columbus, Ohio, and Phoenix. Audubon is raising money for centers in Baltimore and Philadelphia, among other cities, although the recession is making this effort difficult.

But much of the work necessary to diversify Audubon and other mostly white environmental groups has nothing to do with fund-raising and construction. "Opening an Audubon center in a community isn't like building [a restaurant], where you can just plunk something down and customers will come," remarks Audubon president and CEO John Flicker, one of the environmentalists who was inspired to reach out to minority groups by the Florida sugar tax defeat. "An Audubon center is all about building trust and building relationships in the community, and that just takes time."

For example, the Audubon Center at Debs Park in a Latino section of East Los Angeles has been open since 2003, but a survey taken last year showed that 70 percent of nearby residents didn't know it existed, says Jeff Chapman, the interim director. "People tell us, 'We thought this beautiful building was a private facility [where] we weren't welcome.'" To address this misperception, the Debs Park staff has been working closely with day care providers, health clinics and schools—"trusted voices" in the neighborhood.

Keith Russell, an ornithologist who's helping lay the groundwork for an Audubon center in the low-income, mostly black neighborhood of Strawberry Mansion in Philadelphia, says it's important for Audubon and other groups to "listen first and not assume anything" as they reach out to minorities. Russell, who is black, has been teaching Strawberry Mansion residents about birds and nature, but he's also been tailoring his programming to their preexisting interests. "We had one walk right before Mother's Day, and the group said, 'Let's make it a Mother's Day promenade,' and people can come out in their nice hats."

Even though Russell grew up middle-class, he says he has credibility in Strawberry Mansion that a white Audubon staff member wouldn't—and that it's "critical" for Audubon to hire as many people of color as possible to be liaisons to minority groups.

Robert Bullard, one of the founders of the environmental justice movement and a sociology professor at Clark Atlanta University, applauds Audubon's urban nature center campaign, which he says provides "a pipeline for young people to understand that the environment and nature are in their community, not just at the Grand Canyon and Yosemite." But Bullard hopes the Audubon centers will go beyond educating kids about nature and address public health issues such as childhood obesity and the scarcity of grocery stores in inner cities—issues that have historically fallen under the aegis of the environmental justice movement.

The Sierra Club opened an environmental justice unit in the 1990s, in response to criticism from minorities, but in recent years the entire club has made diversity a priority, according to Sanjay Ranchod, a Sierra board member and an environmental lawyer in Atlanta. "Folks really see this as not optional work. This is really necessary for the club to achieve its conservation goals," he says. Sierra's spokespeople now routinely reach out to Spanish-language and black TV networks (Univision and BET, respectively); last year the club elected an Asian-American president, Allison Chin; and a diversity council has formed to oversee the club's efforts to attract more minority staff, members and volunteers.

The Nature Conservancy recently hired a diversity manager, VonGretchen C. Nelson, to help the organization attract and retain minority staff members. In recruiting this summer's paid interns, Nelson focused her efforts on colleges with a preponderance of black, Latino and Native American students; she's hoping that some of the 26 interns will eventually be hired full-time. And The Conservancy is raising money to expand its Urban Youth Program, which pays city high school students to live and work on nature preserves. As the director of the program, Brigitte Griswold, says, "If we can't reflect the overall population, how are we going to engage with the greater community?"