It now appears that a shortage of fresh water is likely to lead of conflicts in many parts of the planet (http://www.theguardian.com/environment/2015/mar/08/how-water-shortages-lead-food-crises-conflicts). This seems to be a direct conseqeuence of the burgeoning human population and development (water consumption per head is 10 times higher in developed compared to developing countries). There are also some ill-advised dam building in certain countries (http://www.theguardian.com/environment/india-untamed/2015/mar/06/ecologically-disastrous-dams-may-go-ahead).