Carbon dioxide: atmospheric fossil fuel power plants

Industrial burning of fossil fuels in power plants and factories is the largest source of human-created atmospheric carbon. Emissions from automobiles—from simply driving cars—are another major, but much smaller, source. The burning of rain forests in areas around the equator is another major source of carbon dioxide in the atmosphere. (This burning is mostly done to clear land for agriculture.) Altogether, these carbon sources are cause for present and future concerns. 

The 25-year, effort to reduce the emissions from automobiles has greatly benefited the air quality over major cities. Even with this success, more needs to be done. None of the successful efforts has had a large impact on the emission of carbon dioxide. Many of the pollution control schemes used on automobiles actually slightly increase the emission of carbon dioxide. Burning natural gas verses coal reduces the sulfur emissions of power plants. It also slightly reduces the emission of carbon dioxide because natural gas has the least carbon and the most hydrogen of any of the fossil fuels. Unfortunately, increased use of natural gas will also increase the quantity that can escape into the atmosphere. Methane, the major component of natural gas is a potent green house gas. 

NCREASING USE OF FOSSIL FUELS (petroleum, coal, and gas) will continue to load the atmosphere with carbon dioxide beyond the apparent capacity of the plant and oceanic sinks to absorb the gas. There has been an estimated 15% increase in atmospheric carbon dioxide since the turn of the century (/). An active response to this worldwide problem is to capture and chemically convert the carbon dioxide at its source of production. Ironically, these conversion processes must be powered by nonfossil fuel sources (solar or nuclear) to achieve a net reduction in atmospheric carbon dioxide. 

Because fossil fuels are the remains of once-living organisms, fuels like coal contain sulfur. In electrical power plants, sulfur burns along with the carbon in coal, forming sulfur dioxide (SO ). There also is some sulfur in gasoline, so motor vehicles are also a source of SO3 (not SO2 because catalytic converters convert SO into SO3). Sulfur dioxide and trioxide are both noxious gases (see the section in chapter 3 titled The NO Problem ) and two of the main components of so-called London smog. Oxides of sulfur cause respiratory disease and contribute to the formation of haze that reduces atmospheric visibility. 

Environmental concerns about global warming have increased interest in reducing the emissions of carbon dioxide into the atmosphere. The man-made sources of carbon dioxide are primarily from fossil fuels, with the combustion of coal for the production of electric power being a major contributor. Power plants are usually very large and centrally located, so capturing the carbon dioxide they generate is technically possible. Whether this is economically or politically possible remains an open question. 

As well as the sulfur cyde, there are other cycles in nature water, nitrogen, phosphorus and carbon. Man has influenced them all, but the sulfur cycle is the most disturbed among aU these cydic processes. Fossil fuels are burned in order to warm up houses and to provide cars, power stations and industries with energy. Then the sulfur that was built into coal, oil and natural gas, millions of years ago, is set free. It is transported as sulfur dioxide to the atmosphere, the SO content of which has increased considerably compared to the equilibrium content of the natural cyde. The acid gas is transported by the winds over the continents, and, long distances from a specific source, people experience a rain of sulfuric acid . This acid rain not only attacks the needles and leaves of trees but also damages the roots of plants. In acidified lakes the ability of fish to reproduce is disturbed. If acidification is not neutralized by liming, metal ions may be leached from rocks and damage animal life. 

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