Aside from just plain bad luck, the things you list don't happen in isolation. Humans have fought bloody wars over land for as long as we've stood upright. Do you think we'll all neatly organize into the remaining habitable land?
I agree climate change could cause wars but I don't agree with the narrative that it will somehow cause 'worse' wars because... worse than what? We've managed to have terrible wars than wipe out whole peoples, and great power competition that almost destroyed civilisation in the 1960s without any climate change required. It's hard to see how things can really get much worse on that front
