But in June, the organizations announced the formation of the Blue/Green Alliance, the first formal partnership ever between a labor union and an environmental group.

The groups established an official relationship because they see a need to address how environmental issues are relevant to the U.S. economy, says David Foster, the alliance’s executive director.

Specifically, the alliance will focus on showing how good environmental practices can create jobs and result in safer workplaces. The groups will also launch campaigns highlighting the loss of manufacturing jobs to countries with poor environmental and labor standards.

"We recognize that we need to have a joint voice to be more effective in managing how workers’ rights are protected and in advocating that environmental protections are maintained," Foster says.

The partnership may be the first of a larger movement by labor unions to raise awareness around environmental issues, says Gary Chaison, a professor of industrial relations at Clark University in Worcester, Massachusetts.

"This is a great platform for the union because it’s difficult to argue against protecting the environment," he says. "This is a way for unions to prove that they are relevant again."

Just as unions rallied around the civil rights movement of the 1960s, this represents another social issue that puts them on the moral high ground, says Tom Walsh, a partner in the White Plains, New York, office of Jackson Lewis.

During the next few months, the alliance will launch its "New Vision for America Tour," in which it will hold events at cities across the country whose mayors have embraced the Climate Protection Agreement, a movement of mayors who have vowed to take action to support the Kyoto Treaty on global warming.

The alliance expects to reach out to other unions in the manufacturing space to join its cause, Foster says. "We expect this to be a catalyst for more unions and environmental groups getting involved," he says.

Esmeralda Aguilar, a spokeswoman for the AFL-CIO, says environmental issues are a focus of some of the labor union’s campaigns, but it doesn’t have immediate plans to launch a formal alliance with an environmental group.

The Change to Win Coalition, a group of several unions that broke from the AFL-CIO earlier this year, plans to launch a campaign in the next several months focusing on the environmental hazards facing truck drivers at ports nationwide, says Carole Florman, a coalition spokeswoman.

Many of these drivers, particularly in the Los Angeles area, are working in dangerous environmental conditions, she says.

Increased labor activity around environmental issues will likely take the shape of corporate campaigns focused on specific employers, labor lawyers say.

To address this, companies need to not only make sure that they are abiding by best practices so they are as clean as possible, but they also need to be proactive, Walsh says.

"If employers feel that this is an issue for them, they can get out in front of it and team up with environmental organizations themselves," he says.

—Jessica Marquez