It's not an existential problem for humanity, but it could be an existential problem for individual humans. Settlement patterns grow up water availability. Th

It's not an existential problem for humanity, but it could be an existential problem for individual humans. Settlement patterns grow up water availability. There's a reason India and eastern China are densely populated while the Sahara has virtually nobody. The U.S. Southwest (LA, Vegas, Phoenix, and smaller cities in SoCal/AZ/UT/NV/NM) urbanized when we developed the technology to dam & control the Colorado River. In 100 years, it's likely they'll be thriving communities in the Sahara, Canadian Shield, Siberia, etc. to make up for the increasing inhabitability of Northern Europe, the U.S. South & Southwest, Indian subcontinent, Middle East, etc. But that's cold comfort for the people who already live in the affected regions, who will have to migrate, die, or spend most of their resources on water infrastructure.