An old cliche describes a global problem facing cities now and in the future: Water, water everywhere, and not a drop to drink.
The modern crisis is that hundreds of millions of people are at urgent risk of losing access to the world’s most precious resource: clean water.
For decades, scientists hoped the answer to the problem could be found through desalination. Purifying ocean water until it was fit for for human consumption seemed to be a clever and important fix.
Trouble is, this filtration technology has had a hard time living up to its promise. It consumes massive amounts of energy, meaning every gallon of water produced can be quite costly.