http://dieoff.org/page174.htm A world population of 2 billion, in addition to having adequate food, renewable energy, and forest products, should also have adequate freshwater resources (Postel, 1997). For agricultural and industrial production as well as public needs, we suggest approximately 1.2 million liters per person each year. Water resources, as with soil, would have to be conserved and pollution controlled. Humans would need to cease the overdraft of ground-water resources, instead, using ground-water in a more sustainable manner. Again, technologies are currently available for the effective management and protection of water resources (Postel, So who is going to leave?