No, THAT is not the question.
The REAL question is, What could happen, how fast would it happen, and could we adapt?
Here are the realities. Climate has changed and has been changing for eons. The recent warming trend *may* have been caused/accelerated by humans - or maybe not - but regardless the Earth has seen this before (and will see it reverse, and reverse again....and again...and again.....).
Given that Climate change is natural (even if we had a hand in it - the process IS natural and would eventually occur without our *help*) - how fast are we talking? An inch a year? 10 feet a year? 1 foot total? 50 feet total? Because I live New England at about 50ft above sea level - I can see that I would be benefactor of earth-warming. Yes indeed there would be other places not so fortunate. But again - how long are we talking about? 1000 years before a global human migration? Or only 10 years? Or next year? We've seen humans/animals migrate in mass - it's natural. Those who adapt survive - those who are stubborn and try to *change* their local environment - die.
-CF