Human interference in biogeochemical cycles:.
All forms of life on Earth are involved in and dependent on the on the interaction among the atmosphere, oceans and the crusts through a variety of biogeochemical cycles. A biogeochemical cycle is defined as the interactions among the organic (bio-) and inorganic (geo-) worlds, and focuses on the chemistry (chemical-), and movement (cycles) of chemical elements and compounds. In its simplest form, cycling describes the movement of elements through various media and their return to their original state. The biogeochemical cycles forms the basis of the biosphere where living organisms can and only survive in. These cycles include the circulation of elements and nutrients upon which life and the earth's climate depend. Some of the more significant biogeochemical cycles are briefly discussed below.
Firstly, carbon is one of the most common elements on Earth and it is the basis of all living organisms. The biogeochemical carbon cycle described the fluxes of carbon in its many forms among the biosphere, atmosphere, oceans, and geosphere. There are four main reservoirs of stored carbon in the carbon cycle; namely (1) as carbon dioxide in the atmosphere; (2) as organic compounds in living or recently dead organisms; (3) as dissolved carbon dioxide in the oceans and other bodies of water; (4) and as calcium carbonate in limestone and in buried organic matter (e.g. natural gas, peat, coal, and petroleum). Carbon dioxide is used up by plants through the process of photosynthesis to build up the carbon compound in the plants. Animals consume plants and use these organic compounds in their metabolism. The carbon compounds in both the plants and animals are returned to the air as carbon dioxide via respiration and also when they die and decay, as microbes digest their biomass. Also, a portion of the carbon compounds decay into peat, then over millions of years, into coal (under very high pressures and worked on by microbes in the absence of oxygen).