Climate system
Introduction
The climate system is a complex, interactive system consisting of the atmosphere, land surface, snow and ice, oceans, and living things. The climate system evolves in time under the influence of its own internal dynamics and due to changes in external factors that affect climate (called 'forcings').
Components of the Climate System
The climate system is made up of five major components: the atmosphere, the hydrosphere, the cryosphere, the land surface, and the biosphere.
Atmosphere
The atmosphere is the layer of gases surrounding the Earth. It is the primary vehicle for both the input of solar radiation and the return of longwave radiation to space. The atmosphere plays a crucial role in the climate system because it transports and redistributes energy and mass around the globe.
Hydrosphere
The hydrosphere includes all the Earth's water, in the ocean, the ground, in ice caps and glaciers, and in the atmosphere. It is a major reservoir of heat and plays a critical role in the global climate system by storing, transferring, and evaporating water.
Cryosphere
The cryosphere includes all forms of water in its solid state, such as snow, ice caps, and glaciers. It plays a crucial role in the Earth's climate system by reflecting sunlight back into space and by storing a significant portion of the Earth's freshwater.
Land Surface
The land surface includes all terrestrial surfaces not covered by ice. It interacts with the climate system through the exchange of energy and water with the atmosphere and the hydrosphere.
Biosphere
The biosphere includes all living organisms on Earth. It interacts with the climate system through the exchange of gases and energy with the atmosphere, the hydrosphere, and the land surface.
Climate Forcings
Climate forcings are factors that influence the balance of the Earth's energy system. They can be either natural or anthropogenic (human-induced).
Natural Forcings
Natural forcings include changes in the Earth's orbit around the Sun, changes in solar radiation, and volcanic eruptions.
Anthropogenic Forcings
Anthropogenic forcings include the emission of greenhouse gases and aerosols due to human activities, such as burning fossil fuels and deforestation.
Climate Feedbacks
Climate feedbacks are processes that can either amplify or reduce climate forcings. A positive feedback amplifies the initial forcing, while a negative feedback reduces it.
Climate Models
Climate models are mathematical representations of the climate system. They are used to understand the climate system and to predict future climate.