Skate the Rideau Canal… while you still can

There was a relatively snowy start to Ottawa’s winter, with two big storms in the first few days of December. This, in turn, helped the Rideau Canal’s freezing process. After an early January cold snap, the Rideau Canal Skateway finally became thick (and safe) enough to open to the public on January 11. A brief foray into the skateway’s history shows that in the first few decades of its existence, opening day typically arrived in December. If the historical trend of warmer winters in Canada’s National Capital Region is any indication, we could be looking at yet another extra-short season on this cultural gem – a UNESCO World Heritage Site.

It is no surprise that global warming is, over time, reducing the average length of the skating season on Ottawa’s skateway. What is alarming, however, is that the pace and scale of the skateway’s decline has come much faster than expected. The signs of later average skateway opening dates was certainly perceptible by the mid 1990s, yet by the late 2010s, visitors still had many weeks available to visit the rink most winters. 

Then, during the 2022-23 season something remarkable happened — the skateway did not open for a single day! Things recovered slightly the following year, with 10 days of open skating in winter 2023-2024 (the second-shortest season — by a long shot). But if one charts the number of skating days since opening (as done in Figure 1), it appears the skateway is in the early stages of collapse. My advice is, therefore, to skate the canal while you can — enjoy this national treasure before it disappears completely.

Figure 1: Average Winter Temperature in Ottawa vs. Season Length of the Rideau Canal Skateway

In hindsight, the warnings from scientists about the skateway’s decline underestimated the urgency: A 2015 letter in the prestigious journal Nature Climate Change warned that skating seasons were getting shorter, and by the end of the 21^st Century, we might expect the average number of skating days on the Rideau Canal to decline to around 20 days per year, with dramatic consequences for tourism in Canada’s National Capital Region. 

Another academic study published in 2018 confirmed the trend and linked it to broader climate system changes. An in-depth 127-page technical report conducted for the National Capital Commission (NCC) in 2021 projected that the number of skating days would continue to decline under both high and moderate global emissions scenarios, but nevertheless found the probability of having “at least 20 skating days annually” remained high until mid-century. Yet, here we are, facing the 2024-25 skating season after two record short seasons and a warmer-than-usual winter forecast ahead of us. Perhaps the recent onset of La Niña can help this season’s prospects, but what of the future? 

In part, the dramatic change in the freezing potential of the skateway can be explained by the phenomenon of non-linearity, wherein the impacts associated with climate change worsen at a greater rate than the observed changes in the climate itself. This nonlinear function explains some of the incredible damage we have seen across the world in recent years, linked with climate change.  Scientific projections expect 2025 to be one of the top-three warmest years on record globally.  

Another part of the explanation includes an acceleration in the rate of global warming. Here in Ottawa, the average winter temperature over the last five years has increased by a whopping 2.72°C since the first five years that the skateway was officially opened five decades ago. That is a remarkable shift, much more than twice the rate of change seen globally. During this time, the average skating season has shrunk from around 70 days to less than 25 days. If the length of the Rideau Canal Skateway’s season is closely correlated with local seasonal temperature change, then it is only natural to expect that the time available for skating (and eating Beavertails) on the canal is limited. 

However, it is not just a matter of the number of days with sufficiently thick ice. One also must assume that at a certain point, the relative costs of maintaining the skateway (currently about $1 million per season) no longer appear to be worth the effort. The question now is whether the skateway’s death spiral can be delayed —or perhaps even entirely avoided —through smart interventions to bolster the skateway’s season length. 

The National Capital Commission (NCC) is making an admirable effort here, commissioning research and exploring new technologies or infrastructure changes that could increase the likelihood of good ice. Everything from using slush cannons, placing aerators in the water, changing the timing of flooding, using lightweight surface-clearing equipment, reducing the mandated ice thickness, increasing the water depth of the canal, removing vegetation, and diverting storm water have all been considered. With a limited annual budget, the NCC will surely be thinking carefully about the payoff of such investments. The challenge now is determining the cost per skating day at which these interventions become worthwhile investments.

The old statistical principle of “regression towards the mean” suggests it is quite possible the most recent two seasons have been an aberration, and a return to at least a few weeks of open skating on the canal is possible in the coming winters. Time will tell. 

Yet, even if the season length rebounds to the current trend, it would be wise to seize the opportunity to skate the Rideau Canal while one still can. A simple linear regression indicates we have a about 40 years before the average season shrinks to less than two weeks. That’s only two generations.  While alternatives may emerge in the meantime, the pressure to avoid costly interventions for minimal gains will likely intensify. So, let us hope for a sustained cold snap and good ice in the coming winters, so we can enjoy this important ritual of modern Canadian life for now, while we come up with new winter rituals for the children of the future.

Ryan Katz-Rosene is an associate professor at the University of Ottawa’s School of Political Studies, with cross-appointment to the Department of Geography, Environment, and Geomatics. His research examines the intersections of political economy and environmental change.