Carbon atmospheric burden

An ideal renewable resource will be one that can be replenished over a relatively short timescale or is essentially limitless in supply. The latter will include solar radiation, geothermal energy, oxygen, carbon dioxide and water. Nor should production or consumption of these resources contribute to the net atmospheric burden of carbon dioxide. Advantage can be taken of the fixation of atmospheric carbon dioxide into plant material by the process of photosynthesis. 

On the global-scale, the destruction of ozone by halocarbons was addressed in the U.S. by banning chlorofluorocarbons in aerosol products. The release of carbon dioxide to the atmosphere from fossil fuel combustion wil1 continue well into or through the twenty-first century. Energy requirements of nations of the temperate zone will require combustion of gas, oil and coal and the atmospheric burden of carbon dioxide will continue to increase with uncertain consequences. 

Computed changes in the mean temperature of the atmosphere as a function of geographical position and height that would result from a doubling of the atmospheric carbon dioxide burden (Manabe and Wetherald, 1975). (By courtesy of American Meteorological Society)... 

Pg C, 64% of which is due to fossil fuel combustion. The atmospheric C02 mixing ratio rose from a preindustrial value of about 280 ppm to 370 ppm in 2000, an increase of 90 ppm. Each ppm of C02 in the atmosphere corresponds to 2.1 Pg C (see Problem 1.6), so the increase in the atmospheric burden of carbon from 1850 to 2000 was 189 Pg C. Thus, about 43% (189/441.5) of the carbon added to the atmosphere since 1850 has remained in the atmosphere the other 57% has been transferred to the oceans and the terrestrial biosphere. The 370 ppm of C02 translates into 777 Pg C, of which 189 Pg C has been added since 1850. We noted above that 64% of that addition can be attributed to fossil fuel combustion. 

It can be seen that there are natural inputs of pyrolytic PAHs to the environment as there are for atmospheric carbon dioxide. However, unlike C02, anthropogenic PAH contributions in contemporary sediments exceed natural inputs. This increase in environmental burden may, therefore, be significant in its effects on organisms. 

Nuclear energy, which is obtained when nucleons (protons and neutrons) are allowed to adopt lower energy arrangements and to release the excess energy as heat, does not contribute to the carbon dioxide load of the atmosphere, but it does present pollution problems of a different land radioactive waste. Optimists presume that this waste can be contained, in contrast to the burden of carbon dioxide, which spreads globally. Pessimists doubt that the waste can be contained—for thousands of years. Nuclear power depends directly on the discipline of chemistry in so far as chemical processes are used to extract and prepare the uranium fuel, to process spent fuel, and to encapsulate waste material in stable glass blocks prior to burial. Nuclear fusion, in contrast to nuclear fission, does not present such serious disposal-related problems, but it has not yet been carried out in an economic, controlled manner. 

Mixing of the surface ocean waters with the deep ocean will eventually reduce these carbon burdens in the atmosphere and surface ocean, but the characteristic time for this... 

The choice between cap-and-trade systems and pollution taxes rests at least in part on the pollutant in question. For pollutants like sulfur dioxide, CFCs, or carbon dioxide that mix equally in the atmosphere and that pose few or no local health effects, cap-and-trade works well because we are unconcerned about where emissions take place. On the other hand, if we are concerned that limiting emissions might impose too big a burden on the economy, the pollution tax approach is best because sources know that they will never have to pay more for a ton of pollution discharged than the tax. Effluent charges also raise revenue—not a trivial issue in many places, including developing countries. 

In calculating the number of seriously defective births expected to occur in the first generation as a result of the presence of added amounts of carbon-14 in the atmosphere we cannot neglect the rate of diffusion of carbon-14 into the depths of the ocean. The 74 kg of carbon-14 liberated into the atmosphere by 1 year of testing at the standard rate causes an initial increase of 2.3 percent of the carbon-14 concentration, the normal burden of the atmosphere, biosphere, humus, and upper part of the ocean being 3200 kg. This calculation agrees roughly with the statement by Libby that the observed carbon-14 rise... 

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