However, the Asian population will exceed its maximum allowable level (4.5 billion) as early as 2025, and the African population will also exceed its maximum allowable level (1.7 billion) in 2030. In 2050, the populations in Asia and Africa will exceed their maximum allowable level by 990 million and 320 million respectively. The 1995 populations of two most populous nations (China and India) are already above their maximum allowable levels (1,150 million and 760 million respectively).
In the meantime, if assuming that the water utilization rate is 75% greater (with 20% energy still taken from meat) than the standard condition, neither of the future populations in Asia and Africa exceeds their maximum allowable level (7.7 billion and 3.0 billion respectively). As for the two most populous nations, China's population will not exceed its maximum allowable level, but India's population will exceed its maximum allowable level (1.32 billion) in 2025, and the excess will reach 210 million in 2050.
Conclusion
Even in the 21st century, water resources and food supplies are unlikely to be limiting conditions on populations in Oceania, North America, and Europe, which are largely developed regions, or in South America, mainly a developing region- on the whole, and apart from partial variations.
In those regions, water resources are more than sufficient even under quite severe conditions (Condition 3 of Table 3). In South America, let alone the developed regions, water shortage are unlikely to occur even after taking into account the increase in demand for water to be caused by its further industrialization, urbanization, and improvement of living standards.
However, in Asia and Africa, where the populations together make up three quarters of the world total, and will exceed 80% of the same in the 21st century, securing water resources will be the major political issue for governments. Especially in Asia, many West Asian nations are already in the "water stress" condition.
