The encyclical letter Laudato Si is available here on the Vatican website.
Water scarcity may well worsen in this century:
31. Greater scarcity of water will lead to an increase in the cost of food and the various products which depend on its use. Some studies warn that an acute water shortage may occur within a few decades unless urgent action is taken. The environmental repercussions could affect billions of people; it is also conceivable that the control of water by large multinational businesses may become a major source of conflict in this century.[Cf. Greeting to the Staff of FAO (20 November 2014): AAS 106 (2014), 985]
Water shortage will cascade into other problems. Food costs, certainly. The effect on agriculture will certainly have some environmental impact. Will people allow international corporations to control water, especially if there is money to be made? Political upheaval might be the most obvious fallout from this.