Each time she laces up her soccer cleats, defender Natalie Spilger, 28, sees green—and is reminded of her pledge to never again buy a non-reusable plastic water bottle. The founder of GreenLaces, she is one of 38 athletes featured in Champions for Change: Athletes Making a World of Difference (Global Sports Alliance USA, 2010), a book sponsored by the United Nations.

Q: What is GreenLaces?

A: It's two things: a movement and an educational program. The movement is for athletes to buy green shoelaces [$5, $2 of which goes to planet-protecting nonprofits], make a promise to the planet, and wear the laces when they're competing to promote environmental stewardship to sports fans. The other component takes environmental education out of the classroom and into the fun zone of sports. We raise funds to bring kids to local games, and afterward we'll have the players talk to the kids about the environment.

"Policy is really slow, but grassroots organizations can make change happen much faster." —Natalie Spilger

Q: How did you get the idea for it?

A: I was working as an engineer for a while, certifying green buildings, and I remember thinking, "This sucks—no one really cares if these buildings are green." I wanted to green people, not buildings. I also thought that athletes needed to get activated to be a part of the conversation because they can reach such a huge mass of people.

Q: Why shoelaces?

A: I knew that whatever I chose needed to be a tangible necessity, not a trendy accessory. Shoelaces are something that nearly every athlete, and every person, uses daily.

Q: How do you rationalize all the air travel and the consumptive lifestyle of a typical professional athlete?

A: It's amazing how much the athletic world consumes because of convenience. But I try to do everything I can to make up for it. I've organized collections for donations of slightly used gear and auctioned items signed by professional athletes to raise money for GreenLaces and other environmental organizations. GreenLaces is also going to be offsetting the travel for the upcoming FIFA Women's World Cup.