Course for graduate students 1.1 Definition Climate System The climate system is the highly complex system consisting of five major components: the atmosphere, the hydrosphere, the cryosphere, the land surface and the biosphere, and the interactions between them. The climate system evolves in time under the influence of its own internal dynamics and because of external forcings such as volcanic eruptions solar variations and human-induced forcings such as the changing composition of the atmosphere and land use. 2021/2/22 Assessment of climate/change imp 17of42Course for graduate students 2021/2/22 Assessment of climate/change impacts 17 of 42 1.1 Definition Climate System The climate system is the highly complex system consisting of five major components: the atmosphere, the hydrosphere, the cryosphere, the land surface, and the biosphere, and the interactions between them. The climate system evolves in time under the influence of its own internal dynamics and because of external forcings such as volcanic eruptions, solar variations and human-induced forcings such as the changing composition of the atmosphere and land use