Carbon global natural emission

Carbon monoxide (CO) Is one of the most widely distributed air pollutants. It Is formed by natural biological and oxidation processes, the Incomplete combustion of carbon-containing fuels and various Industrial processes. However, the largest Individual source of man-made emissions Is motor vehicle exhausts which account for virtually all CO emitted In some urban environments. It has been estimated that global man-made emissions range from 300-1600 million tons per year, which Is approximately 60% of the total global CO emissions (22-23). 

At present, roughly 80% of the current global energy needs comes from fossil fuels. Besides, oil is used as a raw material for the production of several chemical products. Ethanol (C2H5OH), a natural product obtained from biomass, is, on the one hand, a renewable source of energy that would be an important factor for near-zero carbon dioxide (C02) emissions, on the other hand, it is the basis for a C2 chemistry, that is, a raw material for the production of different chemical products [19,21,137-147], Besides, ethanol is accessible, can be easily transported, biodegradable, has low toxicity, and can be transformed by catalytic reactions [137],... 

Carbon is naturally contained in all of Earth s compartments the global carbon cycle is a description of how carbon moves among those compartments in response to perturbations, such as emissions from fossil fuel burning and deforestation. Compartmental models of... 

Out of the 28 Gt of CO2 released every year into the atmosphere by human activities, some 21.5 do in fact come from fossil fuels and the rest, i.e. 6.5 Gt are due mostly to deforestation (34, 42, 43). The figure of 28 Gt does indeed appear low compared with the 770 Gt/year of natural CO2 emissions (i.e. 96.5 % of the total emissions) (43), and from this view point industrial activities (industries, electric power stations) and those related to transport would only be responsible for 2.2 % of global emissions and petroleum only for 1.3 % (44, 45). But unlike natural emissions which are part of a natural carbon cycle and are offset over one year by the same volume of CO2 that is absorbed or transformed, these 28 Gt would be considered as an excess volume of emissions, not offset in the yearly cycle (this still has to be ascertained). It is generally accepted that a minimum of 120 years would be necessary to return to the initial situation of 1860 if CO2 were to be brought back to its level at that time (39). 

Implementation of the 1998 Kyoto Protocol, which is designed to reduce global carbon emissions, will have dramatic effects on fossil fuel usage worldwide. The Kyoto Protocol mostly affects delivered prices for coal and conversion of plants to natural gas, nuclear and/or renewable resources. However, as pointed out by the International Energy Agency, increased natural gas consumption in the United States may likely have the effect of increased reliance... 

Natural gas will continue to be substituted for oil and coal as primary energy source in order to reduce emissions of noxious combustion products particulates (soot), unburned hydrocarbons, dioxins, sulfur and nitrogen oxides (sources of acid rain and snow), and toxic carbon monoxide, as well as carbon dioxide, which is believed to be the chief greenhouse gas responsible for global warming. Policy implemented to curtail carbon emissions based on the perceived threat could dramatically accelerate the switch to natural gas. 

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