Sometimes environmental literacy means taking simple actions like buying "green" products or using natural alternatives to pesticides—like marigolds—to keep pests away.

Sometimes it involves attending community meetings to discuss complex issues like whether to build a new stadium or rehab the old one—or whether to use the land for another purpose altogether, such as reserving it for parks and playgrounds.

And sometimes it means taking public transportation instead of driving a car to reduce air pollution—or working with businesses, urban planners, and policy makers to investigate and address health risks from building materials such as asbestos or industrial waste, and raise awareness about the health impacts of decisions they make about the built environment.