At Ohio Stadium in Columbus, Ohio, fans on hand for the Buckeyes’ game Saturday against Buffalo were met with new Zero Waste stations and more environmentally friendly food and drink containers, (Kirk Irwin/Getty Images)

With thousands of fans roaring above them, the Ohio State University Buckeyes burst into Ohio Stadium on Saturday to start their latest quest for a No. 1 college football ranking and a national championship.

But high in the scarlet and gray bleachers that hold up to 105,000 people, Buckeye fans were asked to play a role in another goal this season: eliminating garbage. High school students manned Zero Waste stations, showing fans where to stick trash that can be composted and recycled, and where to put the rest.

Ohio State worked with food vendors to switch from plastic to fiber nacho trays because plastic couldn’t be recycled with cheese stuck to it, said Corey Hawkey, the university’s sustainability coordinator. They also switched to wax paper to wrap hot dogs instead of aluminum foil, and got rid of paper cups with plastic lids, substituting plastic souvenir cups to be taken home.

Ohio State is among at least 200 schools that are trying to make their athletic programs greener. The interest across the country was on display last week at the first Green Sports Alliance Summit in Brooklyn.

Six hundred representatives from college and professional athletic organizations discussed ways to take chemicals out of lawn care, equip huge stadiums with low-flush toilets, treat wastewater on site and use it to irrigate the grounds, and reduce energy bills with wind turbines and solar panels.

“We’re doing it to show it can be done,” said Jay Kasey, Ohio State’s senior vice president for administration and planning. “We want to get students and get faculty involved in our most visible activity, seven home football games a year.

“We felt that if we could do this in football stadiums, we’ll learn a lot of techniques we can use across campus,” Kasey said. “If you can do it there, you can do it anywhere.”

As part of the summit, the Natural Resources Defense Council released a report, “Collegiate Game Changers: How Campus Sport Is Going Green.” It followed a similar report last year, “Game Changer: How the Sports Industry Is Saving the Environment.” Both describe how American sports have moved toward greater energy efficiency since 2007.

Sports have a long way to go before all franchises and institutions can be credited with dramatically shrinking the mountains of pollution they generate. But Alice Henly, a resource specialist and coordinator of college sports at Natural Resources Defense Council, said the summit is proof that the ball is rolling in the right direction.

“All sports and all major events have large environmental footprints — football, basketball, tennis, race car driving,” Henly said. “What’s valuable about the sports industry is it brings unique cultural, economic and social influence and visibility. There is this tremendous opportunity . . . to bring people together and encourage them to be environmental stewards.”

The sports arena is a huge stage. Forty-three million people attended NCAA football games in 2005, according to a working paper by the International Association of Sports Economists and the North American Association of Sports Economists. More than 100 million fans attended NCAA basketball events, along with professional football and baseball games that year.

At Ohio Stadium, where about a million fans visit each season, 98 percent of trash was diverted from landfills during a game against Illinois in November. The diversion rate for last season was 87 percent. Only 23 tons of trash went to landfills in 2012, compared with nearly 60 tons in 2010, according to the NRDC report.

“We have 55,000 students and 30,000 workers,” Kasey said. “We’re a midsize city unto ourselves. If we can work with Ohio State’s campus, with all our food needs and energy needs, and show we can reduce it, there are great applications for entire cities our size. And we’re trying to roll those ideas out.”

Many colleges and universities have been pushing environmental sustainability more generally. The Sierra Club maintains a ranking in which the University of Maryland is the nation’s 13th greenest university, the highest rank in the Washington metro area.

But the popularity of sports will capture a wider audience for environmental responsibility, conservationists say.

The University of Florida’s annex to its football stadium, the Heavener Football Complex, is the first building in the football-crazed state and one of the first athletic facilities nationwide to be awarded a platinum certification by the Leadership in Energy and Environmental Design (LEED).

LEED has three ratings, silver, gold and platinum, with platinum the highest award for the most sustainable buildings. Florida’s $28 million addition has a type of glass and insulation that lowers heating and air-conditioning costs.

Daily water use was reduced by 40 percent with low-flow toilets that use significantly less water and dual-flush toilets that allow users to choose the flow. An irrigation system operates with reclaimed water, according to a university statement, and a green roof over a weight room redirects storm water to nourish plants.

Arizona State University has installed a total of 10 solar arrays, groups of different types of solar panels, at more sports facilities than any other college athletics department, the NRDC report said. Nearly half the power used at the Weatherup Center, where the basketball teams practice, is generated by solar energy, earning it a LEED gold certification.

Apogee Stadium at the University of North Texas, powered by wind energy, was the first entire sports venue in the United States to win a LEED platinum certification, in 2011.

“We’re called the Mean Green, and we took on this moniker that ‘We Mean Green,’ ” said Rick Villarreal, the director of athletics.

“We sat down to make a comprehensive list of those things that could be done — nontoxic paint, nontoxic cleaner, retaining water for the grass field,” Villarreal said.

A chiller plant was added to keep the stadium and campus cool by pumping water cooled to 42 degrees through nearly six miles of underground piping, saving an estimated $60 million over 20 years, according to the university.

Sitting in Tornado Alley, officials wondered how they could use wind turbines. “The wind blows through all the time at high levels,” Villarreal said. “We were able to get a grant to put three wind turbines adjacent to the building,” lowering energy usage by 12 percent.

“We put 150 trees around the stadium, use permeable pavement to keep storm water from running off,” he said. It was a message: “If you build a home, use permeables. We used a ton of material that could be shipped from within 500 miles, reducing the amount of gas that had to be used. Those are all things that other people can do.”