The average annual water footprint of humanity from 1996 - 2005 was around 9 trillion cubic meters. Despite higher expenses of kWh per cubic centimeter, water desalination is increasing across the world.
List of top 10 desalinating countries, measured in cubic meters per day (as of 2013):
3 years ago, MIT discussed the high throughput of graphene membranes in desalination. The process is scaleable and has a filtration factor of 99%. ORNL recently claimed an even higher efficiency using cheaper methane-derived sheets of graphene.
This infograph claims that by 2016 Israel will reach 50% desalination-based water generation. They want to meet 50% of agricultural water demand with this technology by 2020. From that same source, Saudi Arabia wants all desalination plants to be powered by solar technology by 2019 themselves. Greece is developing geothermal desalination. The UK is pushing for widespread use of residential smart water meters to monitor pipe leaks and maximize sustainability. In California the largest desalination project in the western hemisphere is expected to reach completion by next year.
For the next few decades, capacity and demand will continue to compete neck and neck. A significant breakthrough is needed to keep up with growing populations and dwindling fossil aquifers. With water use dominated at 92% by agriculture (in many places with sub-par conservation practices), the integration of Soylent into the global market could reduce agricultural use by at least 15%. The water savings could be redistributed to industrial and consumer markets, ideally lowering prices for both users.