A wet future?

The global population is rising and the amount of usable water is declining.  Countries such as the UK, Belgium, Poland and South Africa are already classed as 'water-stressed' (less than 1700 cubic metres per year per capita). Parts of the Middle East and North Africa are further classed as 'water-scarce' (less than 1000 cubic metres).  Countries such as India and parts of Africa are expected to have severe water supply issues in the next decade.  Such areas are also those in which population is expected to grow at the fastest rates.   There is likely to be desperation and conflict over water in the future. 

There are a few different strategies for addressing the water supply problem.   Given that approximately 80% of the Earth's surface is covered by water, it is rather a case of water being in the wrong places and in many cases containing too much salt!   De-salination is possible but needs to be cheaper to perform.  Some new technologies may be able to achieve this.  Nano-technology is one such approach - with new membranes that allow the water to be purified, amongst other ideas.  

Water also has the highest thermal capacity of any commonly available substance.  Humans could learn lessons from nature in this regard where water is an important storage mechanism for energy storage.   Recovering heat from water and recycling waste water are also ways that humans in scarce areas will be able to address the problem.  On the International Space Station, they recycle about 97% of water which infers that space exploration may also offer some innovation for Earth's water shortages.  Mining water from comets in space may be an option in future space travel - though it's harder to envisage this happening very soon!   In the far future, it may be that humans begin getting used to living on or under water more, and embrace a more aquatic lifestyle.