38 | New Scientist | 3 August 2019
Water
from air
With a water crisis
bearing down on us,
incredible materials
that can suck water
from even arid
desert air could
quench our thirst,
says Nic Fleming
T
HREE 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 waterfrom 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 in Jordan in 1965, the sixth of