Climate change is a significant and lasting change in the statistical distribution of weather patterns over period ranging from decades to millions of years. It may be a change in average weather conditions. Climate change may be limited to a specific region or may occur across the whole World.
Climate includes patterns of temperature, precipitation, humidity, wind and seasons. "Climate change" affects more than just a change in the weather, it refers to seasonal changes over a long period of time. These climate patterns play a fundamental role in shaping natural ecosystems, and the human economies and cultures that depend on them.
Because so many systems are tied to climate, a change in climate can affect many related aspects of where and how people, plants and animals live, such as food production, availability and use of water, and health risks.
