The Climate System

The climate system can be defined in the following way an interactive system consisting of five major components; the atmosphere, the hydrosphere, the cryosphere, the land surface and the biosphere, forced or influenced by various external forcing mechanisms, the most important of which is the Sun. According to the Second Assessment Report (SAR) by IPCC (1996), the atmosphere is the most unstable and rapidly changing part of the system, and by this we understand that this system is vulnerable to alterations of the concentration level of greenhouse gases