Likely not, according to Nils Petter Gledditsch, in the introduction to a special issue of the Journal of Peace Research on this topic. Research to date shows little evidence for systematic relationship between increased global warming, water shortages, etc., and violent conflict.
Climate change is the world’s first truly global manmade environmental problem and a firm warning that human activities can influence our physical environment on a global scale. The range of possible consequences of climate change is so wide, even for the limited temperature changes foreseen in the IPCC scenarios, that it is difficult to sort out the main priorities. Obviously, if a reversal of the trend towards a more peaceful world was one of these consequences, it should have a prominent place on the policy agenda. Based on the research reported here, such a pessimistic view may not be warranted in the short to medium run.
In other words—there are a large number of unhappy consequences that may flow from continued global warming. But what evidence we have to date (which is admittedly based either on spotty data, or studies over the shorter term) gives us no very strong reason to argue that an increase in violent conflict is among them.