Carbon Cycle

Scientists believe that the amount of carbon as part of this planet is a fixed amount, and the systems which store, consume and release carbon are in balance. This hypothesisA tentative explanation that accounts for a set of facts and can be tested for further investigation. has yet to be rigorously proved. However, although in itself complex, it is a basis for us to develop an understanding of what is going on, in general terms.

In many different forms, carbon moves between the totality of all living things on earth (the biospherePart of the Earth where life is found. The biosphere consists of all living things, plant and animal. This sphere is characterized by life in profusion, diversity, and clever complexity. Cycling of matter in this biosphere involves not only metabolic reactions in organisms, but also many abiotic chemical reactions. Also called ecosphere), the oceans and living things in them, the landmasses, and the gases surrounding the earth (the atmosphere), in what is termed the carbon cycleThe combined processes, including photosynthesis, decomposition, and respiration, by which carbon as a component of various compounds cycles between its major reservoirs: the atmosphere, oceans, and living organisms., a biochemical cycle.

The vegetation, the land, soil and detritusShed tissues, dead body parts, and waste products of organisms. In most ecosystems, detritus accumulates at the soil surface and other types of surface sediments., sediments, the seas and the atmosphere all store carbon in relatively large quantities when each is considered as a whole. Of course, vegetation contributes part of what it consumes to the soil and detritus, and part is released back into the atmosphere by respiration. Plants absorb carbon dioxideCommon gas found in the atmosphere. Has the ability to selectively absorb radiation in the longwave band. This absorption causes the greenhouse effect. The concentration of this gas has been steadily increasing in the atmosphere over the last three centuries due to the burning of fossil fuels, deforestation, and land-use change. Some scientists believe higher concentrations of carbon dioxide and other greenhouse gases will result in an enhancement of the greenhouse effect and global warming. The chemical formula for carbon dioxide is CO₂. (CO₂) from the atmosphere in photosynthesisIs the chemical process where plants and some bacteria can capture and organically fix the energy of the sun. This chemical reaction can be described by the following simple equation:
6CO₂ + 6H₂O + light energy >>> C₆H₁₂O₆ + 6O₂
The main product of photosynthesis is a carbohydrate, such as the sugar glucose, and oxygen which is released to the atmosphere. All of the sugar produced in the photosynthetic cells of plants and other organisms is derived from the initial chemical combining of carbon dioxide and water with sunlight. This chemical reaction is catalyzed by chlorophyll acting in concert with other pigment, lipid, sugars, protein, and nucleic acid molecules. Sugars created in photosynthesis can be later converted by the plant to starch for storage, or it can be combined with other sugar molecules to form specialized carbohydrates such as cellulose, or it can be combined with other nutrients such as nitrogen, phosphorus, and sulfur, to build complex molecules such as proteins and nucleic acids. Also see chemosynthesis. It is said that photosynthesis gives rise to three quarters of the world supply of oxygen that we breathe. and release it into the atmosphere as CO₂. Decaying matter in the ground releases CO₂ into the atmosphere.

Similar exchanges take place between the oceans and the atmosphere, with many different organisms in the sea consuming dissolved CO₂ in photosynthesisIs the chemical process where plants and some bacteria can capture and organically fix the energy of the sun. This chemical reaction can be described by the following simple equation:
6CO₂ + 6H₂O + light energy >>> C₆H₁₂O₆ + 6O₂
The main product of photosynthesis is a carbohydrate, such as the sugar glucose, and oxygen which is released to the atmosphere. All of the sugar produced in the photosynthetic cells of plants and other organisms is derived from the initial chemical combining of carbon dioxide and water with sunlight. This chemical reaction is catalyzed by chlorophyll acting in concert with other pigment, lipid, sugars, protein, and nucleic acid molecules. Sugars created in photosynthesis can be later converted by the plant to starch for storage, or it can be combined with other sugar molecules to form specialized carbohydrates such as cellulose, or it can be combined with other nutrients such as nitrogen, phosphorus, and sulfur, to build complex molecules such as proteins and nucleic acids. Also see chemosynthesis. It is said that photosynthesis gives rise to three quarters of the world supply of oxygen that we breathe. and releasing it when they die and decay. Different levels within the seas interact with marine biota and sediments in different ways.

Apart from these carbon exchanges, other instances are man's burning of fossil fuelsCarbon based remains of organic matter that has been geologically transformed into coal, oil and natural gas. Combustion of these substances releases large amounts of energy. Currently, humans are using fossil fuels to supply much of their energy needs. and the uses man makes of the land.

Energy derived from fossil fuelsCarbon based remains of organic matter that has been geologically transformed into coal, oil and natural gas. Combustion of these substances releases large amounts of energy. Currently, humans are using fossil fuels to supply much of their energy needs. - coal, oil, natural gas - is consumed in power generation, in industry, our homes, and for transportation by cars, trucks, ships, and aircraft. Carbon is taken as fossil fuelsCarbon based remains of organic matter that has been geologically transformed into coal, oil and natural gas. Combustion of these substances releases large amounts of energy. Currently, humans are using fossil fuels to supply much of their energy needs. from their stores in the earth and used to generate energy and then released on a one way journey into the atmosphere.

Man releases additional ammounts of cardon into the atmosphere by changing the uses of the land, for example by clearing land for agriculture, mining and urbanisation. Cutting down tropical forests for fuel, building materials, or to make way for growing crops, releases the carbon stored within them.

Calculations have been made of the mass of carbon in the various stores measured in Giga tons of Carbon. Estimates are as follows: in the worlds forests 580 Gt C (+/- 30 Gt C), in the soils and detritusShed tissues, dead body parts, and waste products of organisms. In most ecosystems, detritus accumulates at the soil surface and other types of surface sediments. 1,390 Gt C (+/- 190 Gt C), in the surface oceans 960 Gt C (+/- 60 Gt C), in intermediate and deep oceans 36,000 Gt C (+/- 2,000 Gt C), in sediment 150 Gt C, in marine biota 3 Gt C, and in the atmosphere 745 Gt C (+/- 5 CT C).

Annual rates of of carbon mass C transferred as CO₂ to and from the atmosphere have also been estimated as follows: to vegetation 110 Gt C, from vegetation 50Gt C, to ocean's surface 98.5 Gt C, from ocean's surface 96 Gt C, attributable to land use 0.5 Gt C, from land use 1.6 Gt C. Vegetation transfers 60 Gt C into soil and detritus, the mass transferred from soil and detritus is unknown. Cycling within ocean levels transfers 68.5 Ct C from surface layers to intermediate and deep layers, with 64.3 Gt C returning back to surface layers (both these transfers have high margins of error).

The diagram below shows these numbers in a way that can be more easily understood. It can be seen that man is adding 7.70 giga tons of carbon to the atmosphere every year, and rising as emerging industrial nations (such as India, China and Brazil) become heavier CO₂ emitters. That rate of 7.70 Gt C pa would represent more than a 10% addition every year to the atmosphere (depleting the worlds biospherePart of the Earth where life is found. The biosphere consists of all living things, plant and animal. This sphere is characterized by life in profusion, diversity, and clever complexity. Cycling of matter in this biosphere involves not only metabolic reactions in organisms, but also many abiotic chemical reactions. Also called ecosphere and land mass store of C by a similar quantity).

Source: Norman Hopkins 2006 (image 790x997)