Environment carbon cycle role

The chemistry of carbon, and radiocarbon, in the atmosphere represents one of the most important areas of environmental research today. The primary practical reason for this is the increasing attention which must be paid to the critical balance between energy and the environment, especially from the viewpoint of man s perturbations of natural processes and his need to maintain control. Probably more than other species, carbonaceous molecules play a central role in this balance. Some of the deleterious effects of carbonaceous gases and particles in the atmosphere are set down in Table 3. The potential effects of increased local or global concentrations of these species on health and climate have led to renewed interest in the carbon cycle and the "C02 Problem". It should be evident from the table, however, that carbon dioxide is not the only problem. In fact, the so-called "trace gases and particles" in the atmosphere present an important challenge to our interpretation of the climatic effects of carbon dioxide, itself [20]. 

One of the most important components of the chemical perspective of oceanography is the carbonate system, primarily because it controls the acidity of seawater and acts as a governor for the carbon cycle. Within the mix of adds and bases in the Earth-surface environment, the carbonate system is the primary buffer for the aridity of water, which determines the reactivity of most chemical compoimds and solids. The carbonate system of the ocean plays a key role in controlling the pressure of carbon dioxide in the atmosphere, which helps to regulate the temperature of the planet. The formation rate of the most prevalent authigenic mineral in the environment, CaCOs, is also the major sink for dissolved carbon in the long-term global carbon balance. 

The most important component of the carbon cycle is the gas carbon dioxide (C02), and almost all of this section will be about this compound and the role it plays in the environment. 

This account is directed almost exclusively to low-molecular-mass xenobiot-ics so that a discussion of biosynthetic reactions mediated by microorganisms and of biopolymers lies beyond its assigned limits. A few brief comments seem justified, however, because of an upsurge of interest in various groups of naturally occurring compounds, the structure of these biopolymers, and their role in carbon cycling in the environment. Attention is therefore drawn to a few of these, some of which may be persistent. 

The already mentioned feedback between the water and carbon cycle (see also Fig. 2.31) is not only given by the essential role of water in sustaining all forms of life. Observational evidence indicates that transpiration rates of plants are high at the same time as CO2 fixing by the plants, and hence CO2 flux from the atmosphere to the plant canopy is large. When an environment is humid, plants grow more rapidly, draw more CO2 from the atmosphere, and release more water to the atmosphere. 

Electrochemically active biofilms have great importance in the natural environment, principally in metal oxidation and reduction and the associated effects on mineral dissolution, the carbon cycle, and the sorption and complexation of phosphorus and heavy metals. We are also now seeing that they may have a larger role in fulfilling a need for bioenergy production through direct electricity generation. 

Environmental Chemistry. Carbon dioxide plays a vital role ia the earth s environment. It is a constituent ia the atmosphere and, as such, is a necessary ingredient ia the life cycle of animals and plants. 

Biomethanogenesis plays a major role in the cycling of carbon in nature. It has been reported in a broad variety of environments where organic decomposition... 

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