Water scarcity is going to become a reality in the coming decades, it's not that hard to predict this, especially when you look at how Africa's population is projected to increase into the billions over the next few decades, however much of the current water scarcity comes from misuse of water resources.

Sahara is already growing and expanding into the Sahel region of Africa, regions in North Africa will either have to develop extensive (and expensive) water desalination like Israel does, or will have to migrate elsewhere due to lack of water. African aquifers in countries like Libya are already over-exploited, and the water in them cannot be replaced due to lack of precipitation in the region.

Water scarcity in nations with unstable governments, causes local militias, the government and various other factions to 'police' the water sources themselves, denying other people what should be a fundamental right, and increasing instability in the region on a national and local level. The cause of its disappearing is likely due to a compounding of various factors such as overuse for agriculture by the locals as the government is ineffective, but also air pollution affecting rainfall patterns moving the traditional rains further south preventing it from replenishment.

One example of this has happened in Yemen, whose population rapidly expanded in the second half of the 20th century and has now begun to shrink. As more and more people needed more and more water, they dug more and more deeper wells. Now most of the wells in the country have dried up, or turned toxic due to saltwater infiltration from the seas. The dramatic downturn in quality of life in Yemen is what sparked unrest there and made much of the population desperate, hence the growth of Islamic extremism there.

This was also a mistake made by the Soviets, redirecting rivers and such for irrigation, leading to the partial draining of the Aral Sea. The failure to secure adequate water denies the existence of a prosperous agriculture industry leading to most of its population simply subsisting, with the added effect of rampant government corruption and global temperature rises leading to massive droughts.

Yemen is one of the many reasons that the US Department of Defense named water scarcity as a major threat to internal stability in any given country. Almost every single one of the shitholes with civil wars you hear about on the news are experiencing an unprecedented water crisis that is ignored because of the conflict there. The loss of good soil and safe water in the third world will make big parts of it uninhabitable by the middle of this century, and all those billions of people won't stay put where they are. A dark future for humanity indeed.