“You would expect it out of a California team, but not an Arizona team,” said Derrick Hall, the chief executive of the Arizona Diamondbacks, which has worked with Arizona Public Service, the local utility, to build a 17,000-square-foot solar canopy at Chase Field, the baseball team’s stadium in Phoenix. “It’s important to a number of companies. They want to know what steps we are taking, and they like to be associated with us and an environmentally conscious team.”

Even though the team is not required to recycle, the Diamondbacks have added 150 new bins for plastic and aluminum bottles in Chase Field and compost all the food and paper waste, helping keep 95 tons of material out of the garbage dump in the first nine months of the year. In 2008, the team added flushless urinals and hand dryers in the bathrooms, and vendors at the stadium now wear shirts made from recycled plastic bottles. To trim its electricity bill, which is several million dollars a year, the team closes its retractable roof earlier in the day to avoid having to turn up the stadium’s air-conditioners.

Like many teams, the Diamondbacks have received no public subsidies for their initiatives. Some measures, like distributing media guides on digital thumb drives, saved thousands of dollars in printing costs. Others, including asking employees to take public transit to work, were part of broader efforts to be greener organizations.

Either way, the initiatives were done voluntarily, not because of mandates from the commissioner’s office. Major League Baseball and other leagues, though, have been sharing best practices among teams and collecting statistics on energy and water use and recycling rates to create benchmarks. The National Hockey League also helps teams send unused food at arenas to local soup kitchens, an effort that that provided 165,000 meals last season and kept 105 tons of food out of landfills. The league has also started buying credits that restore wetlands for every goal scored during the season.

Skeptics say these efforts are a bandage. Stadiums produce tons of waste and use large amounts of energy, teams crisscross the nation on chartered jets and millions of fans drive to games in millions of cars. League officials acknowledge this but say it is all the more reason to promote environmental initiatives.