Environmental effects of coal mining and coal burning
The environmental effects of coal mining and burning are significant and multifaceted. Coal, a combustible sedimentary rock primarily composed of carbon, is a major source of energy worldwide, accounting for approximately 40% of global electricity generation. However, its extraction and combustion have severe environmental consequences. Coal mining, especially strip mining, often leads to land degradation, disruption of water drainage patterns, and habitat loss, making areas uninhabitable for wildlife and unsuitable for farming.
The burning of coal is the largest contributor to human-caused carbon dioxide emissions, which are linked to climate change. Additionally, it releases harmful pollutants, including sulfur and nitrogen oxides that contribute to acid rain and respiratory diseases, and heavy metals such as mercury and arsenic that pose risks to human health and ecosystems. Efforts to mitigate these impacts include technologies like carbon capture and sequestration, though these solutions face challenges in terms of efficacy and cost. As global demand for coal continues to rise, particularly in the wake of economic recovery post-COVID-19, discussions around its environmental impact and the need for cleaner alternatives remain increasingly urgent.
Environmental effects of coal mining and coal burning
DEFINITION: Combustible sedimentary rock composed primarily of carbon and variable quantities of other elements, such as sulfur, hydrogen, oxygen, and nitrogen
Coal mining and the burning of coal as a fuel both have adverse effects on the environment. The burning of coal has been found to be the largest contributor to human-caused increases of carbon dioxide, a greenhouse gas, in the earth’s atmosphere.
Coal normally occurs in rock strata in layers or veins called beds or seams. The earth’s Carboniferous period, some 300 million years ago, provided the special conditions for widespread coal formation. Coal formed as layers of plant matter accumulated at the bottoms of bodies of water, protected from biodegradation and oxidation, most often by mud or acidic water. Eventually, the plant matter buried by changed over time and through geological action to create the solid known as coal.
Classifications and Uses
Types of coal are classified based on the pressures and temperatures to which their precursors were subjected, known as their degree of metamorphism. From lowest to highest degree of metamorphism, the types of coal are lignite, subbituminous, bituminous, and anthracite. Darkness of color and hardness both increase with rank. Accordingly, the harder coals, and bituminous, are also known as black coals, and the softer coals, subbituminous and lignite, are known as brown coals.
Coal is most commonly used as a fuel for the production of electricity and heat. Coal-fired generation accounts for roughly 40 percent of electricity throughout the world. In some countries, this figure is significantly. When coal is used to generate electricity with a standard steam turbine, the coal is pulverized (crushed or ground into powder form) and then burned in a furnace equipped with a boiler. The furnace heat causes the boiler water to convert into steam, and the steam powers spin turbines that turn generators, creating electricity.
Another important use of coal is in the form of coke. In the production of coke, low-ash, low-sulfurbituminous coal is baked such that the fixed carbon and residual become fused. Coke is used as a fuel and as a reducing agent in the process of smelting iron ore in blast furnaces.
Mining
The majority of coal is strip-mined. In this process, large industrial machines strip off soil and coal, scarring the land. In some nations, laws have been passed that require mining companies to restore the land after mining operations have ended, but such projects often leave much to be desired. It has been estimated that up to one-fourth of the 3.2 million hectares (8 million acres) that are above coal mines have subsided—that is, the ground on the surfaces above the mines has caved in. Coal mining has also sometimes resulted in water drainage patterns that make land unfit for farming and uninhabitable for wildlife.
The act of mining coal also presents health risks. Even in the twenty-first century coal mining remains one of the most dangerous occupations, killing more than one hundred people per year in the United States. Further, coal miners are subject to long-term inhalation of coal dust and other dusts, and so are susceptible to emphysema and other respiratory conditions such as coal workers’ pneumoconiosis, commonly known as black lung, a chronic, potentially fatal disease that causes extreme discomfort and reduced lung function.
Controversies
Because of its global abundance and relatively low cost, coal is a mainstay for both developed and developing nations, which use it for power generation and steel production throughout the world. The burning of coal, however, contributes significantly to carbon dioxide (CO2) emissions, which are linked to global warming, and to the generation of sulfur and nitrogen oxides, which are elements in acid rain. It also releases heavy metals (including mercury, selenium, and arsenic) that are harmful to the and human health, and it generates products (fly ash, bottom ash, boiler slag, gypsum) that pose disposal problems. Other environmental problems related to the mining and use of coal include disturbances of and water-table levels, contamination of land and waterways and destruction of property caused by spills of fly ash, disturbances to water use on flows of rivers, and dust generation.
The pollutants generated from coal burning affect not only the environment but also human health. Sulfur dioxide is associated with respiratory diseases such as asthma, bronchitis, and emphysema. Nitrogen oxides similarly are known to irritate the lungs, cause bronchitis and pneumonia, and lower the body’s to respiratory infections. Particulates from coal burning, when inhaled, can damage the respiratory system, causing acute and chronic respiratory illnesses.
Given that the continuing use of coal to meet the world’s energy needs will exacerbate both the problem of and other negative environmental impacts, scientists recognize that there is a growing need for technologies that can better manage the emissions generated by coal burning. Carbon capture and sequestration or storage (CCS), also known as carbon dioxide air capture, is a technology in which the CO2 generated by coal burning is captured or eliminated before it can be released into the air. CCS, however, has not yet demonstrated its efficacy and safety on an industrial scale at competitive cost.
Amid a global economic recovery following the worldwide COVID-19 pandemic that began in 2020, the International Energy Agency reported that the global consumption of coal reached a record high in 2022. However, in 2024, the Environmental Protection Agency (EPA) announced new regulations that required all coal plants in the US to reduce their greenhouse gas emissions by 90 percent by 2039.
Bibliography
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