Global Warming Means Mass Starvation
This is a world [the world after climate change] where people are starting to starve, but it is not always the familiar scene of helpless peasant societies facing famine with numb resignation. Some of the victims now are fully developed, technologically competent countries and their people will not watch their children starve, so long as there is any recourse, however, illegitimate, that might save them. So the lucky countries in the northern tier that can still feed themselves — but that have little or no food to spare — must be able to turn back hordes of hungry refugees, quite probably by force. They must also be able to deal with neighbours who try to extort food by threats — and these desperate neighbours may even have nuclear weapons. Appeals to reason will be pointless, as it is reasonable for nations to do anything they can to avoid mass starvation.~ Gwynne Dyer (1943-04-17 age:74) Climate Wars: The Fight for Survival as the World Overheats page 4
Consider how badly the USA has behaved in its desperate pursuit of oil. Nations will behave even worse to avoid mass starvation.