I grew up hearing about growing up in Canada. When my parents said, "In my day, we walked miles through 10 feet of snow," they weren't kidding. But what I heard most about from my dad was hockey: watching Hockey Night in Canada starting way back in 1952, or occasional forays to the Forum to watch the Canadiens play one of the other Original Six NHL teams. But mostly, pond hockey. Throughout the long Montreal winter, my father and his friends would finish school and skate on the frozen ponds and rinks in small city parks until it got dark.

But those outdoor rinks are starting to feel the heat. A study published today in the journal Environmental Research Letters found that the outdoor skating season in Canada has diminished significantly since 1951 as temperatures have risen. Researchers led by Nikolay Damyanov of McGill University in Montreal (where both my parents went to college, by the way) used data from 142 meteorological research stations around Canada to measure the length of the season, based on the number of days below certain temperatures.

Five of the six regions of the country showed a trend toward shorter outdoor skating seasons. There were also trends suggesting later start dates. "It is hard to imagine a Canada without outdoor hockey, but I really worry that this will be a casualty of our continuing to ignore the climate problem and obstruct international efforts to decrease greenhouse gas emissions," said Damon Matthews, another of the study's authors, of Concordia University in Montreal.

Canada is warming faster than many parts of the world, with a winter temperature increase of 2.8°C (or about 5°F) over the last 64 years.

I started playing hockey when I was five or six years old, but I grew up in Massachusetts, where frozen ponds were hit or miss. Listening to my dad tell it, missing a single day of hockey during his youthful winters would have been unthinkable in the frozen wilds of Montreal. But unfortunately, it is getting more and more thinkable with every ton of CO2 we pump into the air.

Image: Pond hockey in Ontario in 1908, via John Boyd/Wikimedia