Many immigrants to Canada and their families, Mr. McLeman said, find hockey as “an entry point to access mainstream Canadian culture.” He pointed to the N.H.L. defenseman P.K. Subban, whose parents came to Toronto from Jamaica and Montserrat. “It’s our version of the melting pot,” he said. “Anybody who shows up with skates and a stick can join in.”

Rink Watch has helped Canadians understand the real-life consequences of climate change, Mr. Robertson said: “The fact that this could be taken away and is tied to climate has been a real eye-opener.”

Mr. McLeman added: “Your average Canadian will never see a polar bear in the wild, will never see a glacier, will never go to the South Pacific. There’s no personal connection. But say your kids or grandkids might not be able to skate on the backyard rink, and they say, ‘Oh, I see the connection!’”

Canadian officials are coming to grips with the implications of climate change for their open-air town rinks. Brantford, a city of 100,000 people, maintains as many as 25 outdoor rinks each winter through the work of volunteers. The large number of rinks for such a small city means that most young people can skate within walking distance of home.

But Lori-Dawn Cavin, the manager of community recreation development for Brantford, said she was uncertain how long that could last. Despite many days of bitter cold this winter, she said, “Two days of Mother Nature not cooperating, and all their work basically drains away.”

While nothing has been formally decided, city officials are talking about concentrating Brantford’s efforts on a smaller number of artificially refrigerated rinks that will stand up to moderate thaws. So far, they have not acted on the idea because the volunteers are determined to keep the old-fashioned rinks open, and the city is committed to the volunteers.