8.1 Environmental challenges in energy, carbon dioxide, air, water  (Page 3/21)

Nonrenewable energy and the environment

Fossil fuels are also known as non-renewable energy because it takes thousands of years for the earth to regenerate them. The three main fuel sources come in all phases – solid, liquid, and gas – and will be discussed in that order. One overriding concern is the carbon dioxide emissions that contribute to climate change. Figure Fuel Type and Carbon Emissions displays the relationship between fuel type and carbon emissions.

Solid fossil fuel: coal

Coal comes from organic matter that was compressed under high pressure to become a dense, solid carbon structure over thousands to millions of years. Due to its relatively low cost and abundance, coal is used to generate about half of the electricity consumed in the United States. Coal is the largest domestically produced source of energy. Figure Historic U.S. Coal Production shows how coal production has doubled in the United States over the last sixty year. Current world reserves are estimated at 826,000 million tonnes, with nearly 30 percent of that in the United States. It is a major fuel resource that the United States controls domestically.

Coal is plentiful and inexpensive, when looking only at the market cost relative to the cost of other sources of electricity, but its extraction, transportation, and use produces a multitude of environmental impacts that the market cost does not truly represent. Coal emits sulfur dioxide, nitrogen oxide, and mercury, which have been linked to acid rain, smog, and health issues.  Burning of coal emits higher amounts of carbon dioxide per unit of energy than the use of oil or natural gas. Coal accounted for 35 percent of the total United States emissions of carbon dioxide released into the Earth’s atmosphere in 2010 (see Figure Fuel Type and Carbon Emissions ). Ash generated from combustion contributes to water contamination. Some coal mining has a negative impact on ecosystems and water quality, and alters landscapes and scenic views. There are also significant health effects and risks to coal miners and those living in the vicinity of coal mines.

Traditional underground mining is risky to mine workers due to the risk of entrapment or death. Over the last 15 years, the U.S. Mine Safety and Health Administration has published the number of mine worker fatalities and it has varied from 18-48 per year (see Figure U.S. Coal Mining Related Fatalities ).

Twenty-nine miners died on April 6, 2010 in an explosion at the Upper Big Branch coal mine in West Virginia, contributing to the uptick in deaths between 2009 and 2010. In other countries, with less safety regulations, accidents occur more frequently. In May 2011, for example, three people died and 11 were trapped in a coalmine in Mexico for several days. There is also risk of getting black lung disease (pneumoconiosis) This is a disease of the lungs caused by the inhalation of coal dust over a long period of time. It causes coughing and shortness of breath. If exposure is stopped the outcome is good. However, the complicated form may cause shortness of breath that gets increasingly worse.