Energy must be supplied from an external source to keep biological processes running.

Most organisms depend on the sun for energy. Solar energy essential for 2 reasons

-warmth

-photosynthesis

• water and CO2 energy from sun Glucose and oxygen? fuels the plant.

PAR photosynthetically active radiation

Depends on weather; clouds less PAR.

Respiration- Animals or plants releasing CO2 in the environment.

from plant. Animal decomposes, CO2 released, and Carbon cycle is initiated. For the carbon from organisms to reach the atmosphere takes 300 years.

Carbon stored in the environment in various ways: human by products, biomass, rock (Limestone and dolomite).

Carbon exists in Atmospheres, vegetation, fossil fuel production, rivers, soils, marine.

Most of earth's carbon is in sedimentary...