Fresh water makes up about 2.5 percent of all the water on Earth. A small fraction of that, 0.04 percent, is held in the atmosphere in the forms of clouds or water vapor. Mankind has dreamed of harnessing this water source for untold centuries. Ancient civilizations from the Atacama and Namib deserts to the South Downs of England took their cues from plants and rock formations to induce condensation using piles of stones and dew ponds. More recently, scientists have experimented with higher-tech means, strewing chemicals and even shooting laser beams to try to seed clouds and trigger rainfall. (The techniques, however, have so far proved barely more effective than traditional rain dances.)
Today, efforts to coax water from the air have taken on renewed importance as climate change models project significant shifts in rainfall patterns around the world. Adapting to these disruptions will be essential for the world's agricultural industries...
