OTTAWA — The amount of pollution created by vapor from Canada’s oil sands, which contributes to climate change, ranks on par with most major cities in North America, according to a new study by the country’s environmental regulator that was published on Wednesday.

While the connection between the oil sands’ carbon emissions and climate change is well documented, the study, which was funded by the regulator, Environment and Climate Change Canada, and appeared in Nature, is the first to track the vapor produced in the process and the extent of the pollution that results. It also adds the particularly weighty voice of the Canadian government to the debate.

In recent months, the government, under the leadership of the new prime minister, Justin Trudeau, has reversed course on global climate change. While the country’s economy depends heavily on resources like the oil sands, Mr. Trudeau has made climate change a priority on his agenda.

The study was published just as several major oil sands operations were trying to reopen after being evacuated because of a massive wildfire in the Fort McMurray, Alberta area. Earlier efforts to restart operations were abandoned after the fire swung north and reached the perimeter of Suncor’s and Syncrude’s large mines and plants. Large fire breaks prevented any damage, however.