The global water supply is limited, and shortages will affect over 1.8 billion people by 2025. Fortunately, we've discovered a way to pull water from thin air - even in the desert

Jeremy Horner/Panos

THREE MEN in safety goggles stare intently at a clear plastic box filling gradually with fog. Droplets begin to form on the walls. They swell and eventually begin to trickle into the base of the fish tank-like container, forming small puddles. Omar Yaghi smiles broadly and congratulates his colleagues.

This seemingly prosaic moment in a laboratory at the University of California, Berkeley, may go down in history as the moment scientists turned the tide against water shortage. “Seeing those water droplets was one of the most amazing experiences of my life,” says Yaghi. “It meant I could create water where there is no water.”

That was a couple of years ago. Yaghi is now moving beyond drops and puddles, and breaking out of the lab. In his most recent trials, he sucked significant amounts of water from even arid desert-like air. The secret to it all? A sprinkling of extraordinary synthetic crystals based on a form of chemistry he helped pioneer two decades ago.

The potential implications are dramatic. The United Nations says the number of people living in areas of absolute water scarcity, where available supplies are insufficient to meet demand, will rise from 1.2 billion in 2014 to 1.8 billion in 2025. Even places with money to spend on reservoirs, water recycling and technologies like desalination are vulnerable to greater risks of drought as global temperatures and populations rise. Last year, for example, Cape Town in South Africa narrowly avoided “day zero”, the point at which water runs so low that residents are put on survival rations.

Yaghi knows all about water shortage. He was born …