(outdoor hockey rink quality) X (oil revenue) = constant
The paper says "since 1950, winter temperatures in Canada have increased by more than 2.5 C, more than three times the globally averaged warming attributed to anthropogenic global warming."
The authors then analyzed the starting date and season length of outdoor rinks since 1950 in six different regions of Canada, being sure to fancy up their analysis by presenting their results as anomalies so that no nonscientists could read their paper and simply learn the answer to the perfectly natural question "so how long has the skating season shortened?"
They also used color-coded graphs which turn out to show that the skating is actually starting earlier, on average, in some regions. They conclude:
"In the most extreme case of the Southwest Canada region, a simple linear extrapolation of the OSS length trend from the last 30 yr of our record into the future shows that the number of viable rink-flooding days could reach zero by mid-century. In the absence of efforts to maintain artificially cooled outdoor rinks, this result implies a foreseeable end to outdoor skating in this region within the next few decades. While other Canadian regions have not seen such dramatic decreases, we nevertheless expect outdoor skating throughout Canada to be significantly negatively affected in the coming decades by continued anthropogenic global warming.But with enough tar sands revenue you can buy all the indoor skating rinks you want, right? It's working in Dubai....
"The ability to skate and play hockey outdoors is a critical component of Canadian identity and culture. Wayne Gretzky learned to skate on a backyard skating rink; our results imply that such opportunities may not available to future generations of Canadian children."