LEILA FADEL, HOST:
The canal running through the Canadian capital of Ottawa had welcomed skaters for more than 50 years. But this year, for the first time, the commission that manages the world's longest skating rink announced it won't open. As Emma Jacobs reports, scientists are trying to figure out how to sustain a beloved tradition as global temperatures rise.
EMMA JACOBS, BYLINE: For the past three decades, Laura Urrechaga has woken up on winter nights to the sound of workers preparing the Rideau Canal for skating.
LAURA URRECHAGA: Three in the morning - 'cause I live a few houses down that way. And if I look out my window, I can see them clearing off the surface, flooding the surface.
JACOBS: As an avid skater, she doesn't mind it.
URRECHAGA: On really, really good days, it's just beautiful. It's so smooth.
JACOBS: But this year, the five-mile stretch has been mostly quiet. It never got solid enough to safely support the thousands of people who normally converge here on weekends. Temperatures fluctuated above and below freezing.
SHAWN KENNY: That causes a lot of problems structurally for the ice in terms of its ability to carry load or weight - both people skating on the canal, but also the equipment.
JACOBS: Ice researcher Shawn Kenny meets me near one of the wooden staircases down to the ice, roped off now, to visit a set of sensors he has embedded in the canal.
KENNY: It's down past this series of huts here.
JACOBS: Those are shuttered concession stands for skaters. Kenny's heading a team of engineers and scientists researching ways to maintain stronger ice. They're advising the commission that manages the skateway (ph). He stops where a combination of instruments that looks a little like a rooftop TV antenna stick up out of the canal.
KENNY: And so we can measure temperature in the snow cover, in the ice cover and the water column.
JACOBS: Kenny, who would regularly skate to his office at Carleton University, had noticed skate season change since his first winter in Ottawa in the '80s. It's lost an average of four days per decade, mostly from the start of the season as ice takes longer to form.
NATHAN GILLETT: The coldest temperatures are actually warming more quickly than the warmest temperatures.
JACOBS: Environment Canada spokesman Nathan Gillett says temperatures in Canada are warming faster than the global average, and they're changing unevenly.
GILLETT: We're seeing warming in all seasons of the year. The warming is strongest in winter.
JACOBS: In Ottawa, the research group is piloting a number of possible responses. In December, they tested a slush cannon to encourage early ice formation. For next winter, Kenny's team is 3D-printing, a remote-controlled snow-clearing robot. It can go out on thin, early ice to clear snow, which otherwise acts like an insulating blanket on the ice.
KENNY: From that, we can then think, OK, if we have 10 of these, we could clear X amount in so much time, given a certain snowfall event. Is that scalable or feasible at one, two, five kilometer lengths of the Rideau Canal?
JACOBS: They will also look at thermosiphons, underground heat redistributors. They're used up north to protect structures resting on thawing permafrost. All these strategies will likely only work in the medium term. By the 2050s, Ottawa winters could get five weeks shorter. How much so depends on how the world does at addressing climate change. He hopes some of these strategies could be feasible for a while because he, like others, misses being out on the ice.
KENNY: When you look at it here and there's - you know, it should be a skating season and there's nobody on the ice. It's - yeah, it's strange.
JACOBS: And strange not to be out there himself, skating to work.
For NPR News, I'm Emma Jacobs in Ottawa.
(SOUNDBITE OF SATOSHI NAKAMOTO SONG, "LAST SONG EVER") Transcript provided by NPR, Copyright NPR.