In spite of the frequent historical record of climactic events such as monsoons, floods and also typhoons in China, the recent intensity and regularity of such extreme events has been attributed to both global warming trends and rapid increase in carbon dioxide emission. Some scientists believe that in a warmer climate the earth can be expected to experience more variable weather than now, with a likelihood of more floods and drought, more intense hurricanes or typhoons, and more heat waves. El Nino events have been known to bring catastrophic events. El Nino events typically occur at three to four year intervals, however they are not always predictable. El Nino is the warming of the Pacific ocean waters.
Atmospheric pressure is high in cool places and low in warmer places.
In the case of China, the wind flowing over the land is cooler, thus the pressure is always going to be higher than that of the ocean around it during the El Nino years. High pressure is usually associated with drought. Researchers know that El Nino events are more frequent with rising temperatures, but here are many question still unanswered about the oscillations. It is unclear what Global warming will do to China's catastrophic weather. Some say that the Northwest Pacific basin will experience less severe tropical cyclones during El Nino years.