Fine mesh "fog catching" nets, 

 stretched between poles, 

 collect usable water from fog. 



Pipe directs rain from 

 rooftop into cistern in 

 "rooftop harvesting." 



An iceberg towed from Antarctica 

 to Saudi Arabia or Australia would 

 alleviate the country's water shortage, 

 but would cost billions and wreak 

 environmental havoc. 



on straws 



Filtration 

 trap disease-causing 

 bacteria, enabling 

 people to safely drink 

 untreated water. 

 Two million people 

 use the straws, which 

 cost $3 each. 



Desalination cone placed over 

 saltwater in the sun evaporates the 

 water, which condenses on the 

 cone's inner wall and trickles down 

 into a collection channel around 

 the bottom edge. 



natural history November 2007 



