The climate system is a composite system consisting of five components: the atmosphere, the hydrosphere, the cryosphere, the lithosphere, and the biosphere. These components interact and thereby maintain an always changing, yet relatively stable environment that sustains life --the most precious and complex thing in the universe . Central in the interaction among the components of the climate system are the motions in the atmopshere and ocean.
Change has been the norm for the state of the Earth's climate system. A central aim of climate dynamics is to explain why the state of the climate system has varied in the way it has in the past and to predict its changes in the future. The concern of the impact of human activities on the state of the climate system has served as a major catalyst for the interest in and the growth of this discipline in climate sciences--a discipline we call Climate Dynamics.