Coal is one of the most plentiful and least expensive fossil fuels in world, and currently accounts for almost 40 percent of energy production in the U.S. The availability and affordability of this fuel source, however, come with trade-offs regarding its effects on the environment, particularly the atmosphere.
Documentation of coal as an energy source dates back to early Chinese, Greek and Roman civilizations, but its use was limited until the early days of the Industrial Revolution when the invention of the coal-powered steam engine created exponential growth in demand. Coal remained as a primary source of energy for industrial uses until demand escalated for another fossil fuel in the mid-1900’s, petroleum. Coal is found on every continent and plays a vital role in energy production, especially in developing countries with growing economies like China and India.
Coal has three primary advantages compared to other fuel sources, both non-renewable and renewable: abundance, affordability and low capital expense needed to build coal-powered generation plants. Coal deposits can be found in over 70 countries around the world, with estimates on global reserves of just under 1 trillion tons. If these estimates are correct, coal reserves will last about twice as long as oil and gas reserves at current rates of consumption. Abundance leads to low and stable prices, while the relative ease of converting coal to energy results in power generation plants that can be built using less capital than facilities powered by many competing fuel sources. These advantages make coal the fuel of choice, particularly in developing countries.
The advantages of coal are now being weighed against two significant disadvantages: the release of carbon dioxide into the atmosphere when it is burned and the dangers posed by the extraction process. The vast majority of the global scientific community is now in agreement that the release of greenhouse gases such as carbon dioxide resulting from the burning of coal and other fossil fuels is warming the Earth’s atmosphere and contributing to global climate change, including disappearing glacier, rising sea levels, and changing weather patterns. Coal-fired power plants are also the greatest contributor to mercury pollution. A second issue with coal is an extraction process that can be dangerous, in particular in developing countries, and other environmental consequences, including acidification of streams.
Coal’s role in global warming has resulted in the calls in the U.S. and Europe for scheduled closures of coal-powered plants to reduce greenhouse emissions. However, reductions in the developed world may be countered by continued demand for coal-fired plants in China and elsewhere. Ultimately, however, the future of coal consumption may depend on one factor, generating energy at the lowest possible cost. If an alternative energy source becomes the most affordable option, the use of coal would likely decline over time. The current cost advantages of coal, however, will likely keep this fossil fuel in demand for some time to come.