In my opinion the only solution is a drastic drop in number of human beings. Thankfully we wont have to do much since nature will do it for us when the droughts begin and the crops start failing. Its fun to think of how we will science ourselves out of this as we go over 8 billion people who all desire an ever increasing standard of living. However the only science we will science ourselves with are going to be fully autonomous suicide drones patrolling our borders for any straggling climate refugees and also drones inside our ruined cities patrolling for dissent.
That's my take on the thing at least