Coal is cheap, making it especially useful for developing nations, but it also releases carbon dioxide and particulate matter. Coal reserves are high in many nations. Coal plants are also relatively simple and are easy to build.
Coal has long been valued for its high-energy content, and ancient civilizations would use it as a source of heat. When early steam engines were in use, they were generally powered by burning coal. Coal plants are fairly simple to build; a coal-burning fire heats water, and the steam created turns large turbines. While natural gas is almost as cheap as coal, China and other energy-hungry nations prefer coal plants.
However, coal also releases a tremendous amount of carbon dioxide when it burns, and many developed nations are phasing it out as a result. However, China and other nations lack the capital needed to use more expensive sources of energy. As its economy continues to grow at 10 percent per year, China needs more and more energy, and coal is the most viable option.
There are ways to make coal a cleaner source of energy, and the particulate matter it generates can be caught. However, capturing and storing carbon dioxide is difficult and expensive, and experts are skeptical of whether storing it underground is a feasible solution.