DON Cherry, a Canadian ice-hockey commentator and fan of the Toronto Maple Leafs (pictured), recently attributed the team's continuing futility—44 years and counting without winning the championship of the National Hockey League (NHL)—to its lack of players born in Ontario, the country's most populous province. He may have been thinking of Wayne Gretzky, the sport's greatest player ever, who grew up in Ontario skating and shooting pucks in a backyard rink made by his parents. Sadly, today's young Ontarians do not have the same opportunity as Mr Gretzky to hone their skills. A study published in March shows that climate change is cutting into the outdoor skating season in Ontario and other parts of the country. Nikolay Damyanov and Lawrence Mysak, two professors at McGill University, and Damon Matthews, of Concordia University, have analysed maximum daily temperatures between 1951 and 2005 from 210 weather stations across Canada. They conclude that the season for outdoor skating on natural ice has shrunk by as much as two weeks over that period as a result of climate change, with fewer and shorter cold snaps in winter. That makes it harder to build and maintain outdoor rinks. The study assumes the outdoor skating season starts when the maximum surface air temperature stays below negative five degrees Celsius (23 degrees Fahrenheit) for three consecutive days. The duration of the season is determined by counting the number of days with a maximum temperature of below minus-five Celsius between this starting point and the beginning of March, when most regions stop maintaining outdoor rinks in the face of spring warming. According to the data, in areas like southern Ontario, where maximum daily temperatures in winter have crept up between 1951 and 2005, the outdoor skating season has been starting later and growing shorter. In the Prairie provinces and British Columbia, hockey players and skaters have witnessed even sharper contractions. Although the analysis stopped at 2005, the researchers say there is nothing to suggest the trend will change. In future, ice hockey and pleasure skating could even become activities that take place only in enclosed refrigerated rinks.

This is particularly bad news for Ottawa. Canada's capital, and Ontario's second-biggest city, is today home to more than 230 outdoor rinks, including the 7.8km (4.8-mile) Rideau Canal, the world's largest. Skating on the canal this year was possible on just 28 days over January and February, making the season the shortest in a decade. With temperatures above freezing and rain turning the canal into the world's biggest puddle, some events based around the NHL's All-Star Game, an annual exhibition featuring the game's best players, had to be cancelled. Other festivities were moved to an artificial rink just three-quarters the size of an NHL one, built at a cost of C$2.1m ($2.1m) and funded largely by the Sens Foundation, a charitable organisation affiliated with the NHL's Ottawa Senators. Even this rink had to close on March 8th when the weather became too warm.

Facing city hall, that artificial rink is Ottawa's first. But the Foundation intends to spend C$200,000 on building another 19 in the city's poorer districts, giving disadvantaged children the opportunity to skate and play hockey. Unfortunately, these will be simple concrete or asphalt pads with boards and nets but no refrigeration systems. As icy winters grow shorter, those children will miss out anyway. On the upside, the rinks will also come with basketball nets.

As Mr Damyanov and his colleagues note, outdoor hockey is currently at the core of Canadian identity and culture. Yet changing weather patterns are likely to render it far less important to future generations of youngsters. After another disastrous season, fans of the Maple Leafs were last week disappointed to miss out on the NHL playoffs for the seventh year in a row. Besides blaming Brian Burke, the team's general manager, for their continuing frustration, they can now add climate change as a culprit.