In 2040, a world war will rage. It will be fought largely over water resources, which will then be chronically scarce. The few countries that still have clean, drinkable water resources will be under occupation by the richer developed countries, which will own their water resources. People will live in scarcity and poverty, famine will reign, disease will be rampant and people will die en masse from malnutrition and poisoning. War will end when humanity is extinct.