China says it plans ongoing efforts at artificial weather modification to enhance agricultural production and better serve disaster relief work. China plans to increase precipitation by 60 billion tons annually through cloud seeding and have a complete weather modification system in place by 2020, a plan published on the Chinese government\'s Web site revealed. In addition to rainmaking efforts, China will extend the coverage of artificial hail suppression to more than 208,000 square miles from the present 180 square miles, it said. Local authorities will have access to weather modification services for agricultural production, exploitation of cloud-water resources, emergency response and the safeguarding of major events, the plan said. China has used weather modification in the past to prevent unpredictable weather from disrupting major events such as the 2008 Summer Olympics, the country\'s officials Xinhua news agency reported.