The meteorologists say they can force rain in the days before the Olympics, through a process known as cloud-seeding, to clean the air and ensure clear skies. China has been tinkering with artificial rainmaking for decades, but whether it works is a matter of debate among scientists. LiveScience
Watch this documentary that looks at the history of weather modification and its use by the military. Among the topics covered are: cloud seeding, HAARP and declassified experiments