About 20% of the world’s population has no access to safe drinking water, and this number will increase as the population continues to grow and global freshwater sources continue to decline. The worst-affected areas are the arid and semiarid regions of Asia, the Middle East and North Africa.

UNESCO has reported that the freshwater shortfall worldwide will rise to 500 trillion gallons/yr by 2025. They expect water wars to break out in the near-future. The World Economic Forum says that shortage of fresh water may be the primary global threat in the next decade.

But 500 trillion gallons/year only requires about 1,500 seawater desalination plants like the ones being built in California and Saudi Arabia. At a billion dollars a pop, that’s a lot cheaper than war and starvation.