Canada’s renowned Rideau Canal Skateway, the world’s largest natural ice skating rink, will not open this season for the first time due to a lack of ice, its operator said on Friday, blaming the closure on climate change. The 7.8 km (4.9 mile) Rideau Canal Skateway, first opened over 50 years ago, is part of a UNESCO World Heritage Site in Canada’s capital city Ottawa that is a top attraction for skating enthusiasts seeking outdoor thrills during Canada’s usually biting cold winters. The National Capital Commission (NCC), which maintains and operates the Skateway, said that although they have been assessing and preparing for the impacts of climate change, their efforts to open the rink this season have “come to an end.” “This year taught us a great deal about the effects of milder winters on the Skateway,” the commission said in a statement on Friday. The NCC has previously said it can only open when the ice is at least 12 inches (30 cm) thick, for which there must be 10 to 14 consecutive days of temperatures between -20 Celsius and -10 Celsius (-4 and 14 degrees Fahrenheit). In Ottawa the mean temperature in January was -5.9 Celsius (21.4 Fahrenheit), according to the Weather Network, well above the -10.3C average. Temperatures this year are being driven by the La Niña weather phenomenon, while climate change has made mild winters more likely than they were a few decades ago, said Doug Gillham, manager of the Weather Network’s forecast centre.