Global warming will affect Canada by a lot of people moving  further north. This will probably not be a problem for Canada for most parts but in others it might get a bit too full.  The densest areas are also the warmest areas.

I think the settlement will change depending on the region and climate.  This is what I think will happen:

Cordillera:
The population density along the coast and in the interior will rise and spread north towards the top of BC.  The amount of people will stay the same in the mountains because it is hard to build there.

Interior Plains:
The population density in the plains would increase as the temperature and climate increases. It would spread north towards the north west territories. Since it is flat people will want to build there.

Canadian Shield:
The population density will probably increase in the livable areas. It will probably not spread north because of the surface bedrock.

St. Lawrence Lowlands:
The population density will decrease slightly because their are other parts of Canada that are warmer areas after global warming. The decrease would only be slight because there are many cities in this region.

Appalachian Region:
The population might decrease slightly because the climate the is in this region would have spread to different locations in Canada.  The decrease would be small because there is a good fishing community.

Arctic Region:
The population will increase a tiny bit because it will become warmer and it is flat. If people moved there they would have a lot of space to spread out.