Canada has high density population areas. Not anywhere near as high as Mumbai (30,000 per sq/km) or Mexico City (8,500) but Toronto does have about 2,600 people per sq/km and by Canadian standards that is a crushing number of people for such a small area and is not sustainable.
Having a population density of 2,600 people per sq/km is clearly unsustainable. When it comes to carbon emissions alone they would emit much more carbon than could be naturally sunk by such a small area and of course could not grow their own food.
But Toronto is part of Canada and most of Canada has a population density of less than one person per sq/km. It is the large expansiveness of our forests, Canada has less than one half of one percent of the worlds population but 10% of the worlds forests, and farmland that make Canada one of the few sustainable countries in the world.
The reason for that is climate and history. Canada was one of the last frontiers, so had fewer people moving here throughout the 17 and 1800's due in large part to the harsh climate and remoteness.
Vitebsk Region's population density is 30.6 people per square kilometer.
Grodno Region's population density is 45 people per square kilometer.
The population density of Sava Region is 31.6 people per square kilometer.
The population density of Whitewater Region is 12.9 people per square kilometer.
Ashanti Region's population density is 148.14 people per square kilometer.
The population density of Mogilev Region is 40 people per square kilometer.
Brest Region's population density is 44 people per square kilometer.
The population density of Gomel Region is 37 people per square kilometer.
Greater Accra Region's population density is 895.45 people per square kilometer.
The population density of Inuvialuit Settlement Region is 0.006 people per square kilometer.
Greater Bergen Region's population density is 136 people per square kilometer.
Upper East Region's population density is 104.06 people per square kilometer.