Clive Cussler said this quote

“ In this century wars will not be fought over oil, as in the past, but over water. The situation is becoming desperate. The world's water is strained by population growth. There is no more fresh water on earth than two thousand years ago when the population was three percent of its current size. Even without the inevitable droughts, like the current one, it will get worse as demand and pollution increase. Some countries will simply run out of water, sparking a global refugee crisis. Tens of millions of people will flood across international borders. It means the collapse of fisheries, environmental destruction, conflict, lower living standards. She paused for a moment. As people who deal with the ocean you must see the irony. We are facing a shortage on a planet whose surface is covered two-thirds with water. ”