An important way that greenhouse warming could affect tropical biodiversity is by changing the length and intensity of wet and dry seasons. Most areas have one or two true dry seasons each year, and even the rainy have periodic drier intervals. In moist forests near the Equator, two dry and rainy seasons alternate yearly. Moving out toward the sub tropics, one of the dry seasons lengthens and the other shortener or appears only a sporadically. Rainy seasons usually coincide with the passage of the sun overhead and peak about a month laer. This outbreaks of polar air masses, and violent windstorms. Such tropical disturbances can be changed dramatically by slight changes in temperature and participation. Under global warming, the number and intensity of hurricanes or wildfires might increase or decrease in a given location. These sort of changes could deeply affect biodiversity because patterns of disturbance seem to be primary contributor to high species diversity in the tropics.