CLIMATE SYSTEM
The climate system is in fact made up of the atmosphere, the hydrosphere (water on the earth's surface), the biosphere (living things), the lithosphere (earth's crust and the upper mantle) and the cryosphere (frozen surfaces), all of which are linked together by the flow of energy and moisture between them.
The main elements of the earth's climate system
- The Sun (the main driver of the climate system
- The Atmosphere (acts like a protective blanket)
- The Oceans (currents help to distribute heat around the globe)
- Water (helps cool the surface (evaporation))
- Land Masses (forests, deserts, glaciers and mountains)
Climate is always changing
It is true that the earth's climate has always changed. In fact the saying "the only constant about climate is change" refects this truth. However, the different factors that can cause climate change operate on very different time scales. Continental drift - the movement of the earth's tectonic plates - has changed the position of land masses on earth over timescales of hundreds of million of years, influencing ocean circulation and the formation of major ice sheets, changes in the earth's orbit around the sun occur on timescales of tens and hundreds of thousands of years, influencing the amount and seasonality of solar radiation the earth receives. Factors such as these have been instrumental in shaping past cilimates of Earth, such as the great ice ages, or the long warm period that characterized earth's climate when dinosaurs roamed the world. However, the enhancement of the natural greenhouse effect through human activity is affecting earth's climate now, will continue to do so in the coming centuries and, is likely to bring about changes in climate that are far more rapid than any experience in human history.