[TMWNN]

>I wonder if global warming could make it into one of the most populous countries in the distant future.

Unlikely. The parts of Canada that aren't settled (and aren't actually in or near the Arctic Circle) are that way not because of temperature, but because the soil is almost entirely unsuitable for farming: Either rocky Canadian Shield, or "swallows locomotives overnight" muskeg (plus infinite numbers of mosquitos).

>Would be funny if there is some canadian cabal trying to speed up global warming.

Canada will net benefit from global warming, yes, because the Northwest Passage will become navigable. But it is not true that temperature is the only thing keeping Canada from being able to support as many people as the US, which has almost identically sized geography.