China

The bureau of weather modification was established in the 1980s and is now believed to be the largest in the world. It has a reserve army of 37,000 people -- most of them sort of weekend warriors who are called to duty during unusual droughts. The bureau has 30 aircraft, 4,000 rocket launchers and 7,000 antiaircraft guns, said Wang Guohe, director of weather modification for the Chinese Academy of Meteorology.