Seriously: there is a train. Yes, it takes probably in the ballpark of five or six days, but since it exists, I really think that's what should be used. Because the friction between steel wheel and the rail is so low, even a diesel train causes about 70 % less climate-warming emissions per kilometre than flying does.

I'm about to go from Helsinki to Ragusa and back with my child who is under 10-year-old, and that's going to be more rail kilometres than your trip through Canada would be. It should be the standard to always travel in normal ways and only fly when no other options exist. (I'd say countries' leaders meeting up or a close relative being about to die any minute are examples of when it's okay to travel in a way that kills people)

I wish some kind of "this many person-kilometres of flying kills one person" numbers would be published. The number exists, we just need to figure out what it is.