In a monumental move for the sports industry, the NHL recently released its first sustainability report. Notably, the report is apparently the first document of its kind published by a North American major sports league.

The report comes nearly two months after the White House called for cuts in emissions by 2030 and after President Barack Obama announced in May that climate change is happening now.

The report focuses on the ways in which the NHL’s franchises are transforming stadiums and other spaces to become more energy-efficient, although there’s little in the way of actual number crunching about the costs versus rewards.

But the report does cite increased efficiency as providing financial incentive to the league. “The shift away from old, inefficient lighting has produced significant returns on investment and lessened environmental impact,” the report cites as an example. Stadiums could also add more efficient boilers and ceiling-mounted downdraft fans to save money, according to the report.

Meanwhile, if you thought the NHL ice rinks were safe from change, think again. The 12,000 to 15,000 gallons of water to create an NHL regulation ice sheet also received an environmental boost through a reverse osmosis process that means less-dissolved gasses within the ice, according to the report.

The NHL details the league’s carbon footprint of approximately 530,000 metric tons of greenhouse gas emissions per year. The breakdown includes 182 game days, 1,230 regular-season games, over 60 playoff contests and about 2 million miles of travel for its teams each season.

In comparison, according to the report, the largest coal plant in the U.S. totals 23 million metric tons, which is sure to make the NHL’s figures look like nothing.

Allen Hershkowitz, who heads the Natural Resources Defense Council’s Green Sports program, called the report a “mainstream wake-up call” in a statement. And, yes, even sports and recreation comes with a price to the environment, he added.

In terms of sports branding, the increased transparency about sustainability by the NHL is a good start, according to marketing expert Bob Dorfman of California advertising firm Baker Street Advertising. “It’s a significant plus for the NHL brand, and puts them ahead of the other pro sports leagues with regard to environmental issues,” he said. “The development of hockey and it’s players, so dependent on water, ice, weather and temperature, is clearly more affected by the environment than are other sports, so a report of this kind makes sense, is timely and relevant.”

Dorfman added, too, that the ecological footprint of pro sports leagues are typically “massive” and that “any league-wide effort” is “extremely important” these days. Plus, “it does allow for cost cutting under the aegis of ‘going green,'” he said.