During 1999,global climate has been warming persistently.The strong La Nina event continued in the central and eastern Pacific and it impacted on world climate,especially in the tropical region.In Europe and North America,cold and snow weather was experienced during winter,while hot weather occurred in summer.Severe floods occurred in south Asia,central Europe,southern North America and northern South America.Drought appeared in West Asia and central North America.South Asia,North America and the northeastern Australia were hit by rare tropical storms,which resulted in severe disasters.