Man-made climate change is said to be threatening the future of ice hockey in Canada, where the sport is a cornerstone of national culture.
Top players have traditionally learned their skills on frozen lakes and backyard rinks but as winters get warmer, experts believe aspiring ice hockey stars in years to come will struggle to find suitable outdoor facilities.
Canadians are passionate about ice hockey. Last year, riots broke out in Vancouver after the home side, the Canucks, lost to rivals the Boston Bruins in the showpiece Stanley Cup final. Cars were set on fire, shop windows smashed, and police used tear gas and pepper spray to restore order.
Earlier this year, the world's longest skating rink, the Rideau Canal Skateway in Ottawa, was closed due to unusually warm seasonal temperatures.
New research was carried out by scientists who used historical data to record changes in the annual start date and length of Canada's outdoor skating season. Of the 142 weather stations studied, only a few showed a significant trend towards earlier start dates since the 1950s.
A much larger proportion showed a statistically significant decrease in the length of the skating season over the past half century. Looking ahead, the scientists predicted a complete end to outdoor skating within the next few decades in regions such as British Columbia and Southern Alberta.
All areas of southern Canada could be vulnerable to continued winter warming, they believe. The findings are published in the Institute of Physics journal Environmental Research Letters.
Co-author Dr Damon Matthews, from Concordia University in Montreal, said: "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 effort to decrease greenhouse gas emissions."
It takes several cold days to lay the initial layer of ice on a rink. The researchers defined the start of the outdoor skating season as the last in a series of three days where the maximum temperature stays below minus 5C. Canada appears to have been more affected by global warming than many other countries.
Since 1950, winter temperatures in the country have increased by more than 2.5C - three times the global average attributed to man-made warming.