Earth, Climate & Environment

Environmental Effects Of Using Fossil Fuels

Acid rain and global warming are two of the most serious environmental issues related to large-scale fossil fuel combustion. Other environmental problems, such as land reclamation and oil spills, are also associated with the mining and transporting of fossil fuels.

Acid Rain
When fossil fuels are burned, sulfur, nitrogen, and carbon combine with oxygen to form compounds known as oxides. When these oxides are released into the air, they react chemically with atmospheric water vapor, forming sulfuric acid, nitric acid, and carbonic acid, respectively. These acid-containing water vapors—commonly known as acid rain—enter the water cycle and can subsequently harm the biological quality of forests, soils, lakes, and streams.

Ash Particles
Combustion of fossil fuels produces unburned fuel particles, known as ash. In the past, coal-fired power plants have emitted large amounts of ash into the atmosphere. However, government regulations also require that emissions containing ash be scrubbed or that particles otherwise be trapped to reduce this source of air pollution. While petroleum and natural gas generate less ash than coal, air pollution from fuel ash produced by automobiles may be a problem in cities where diesel and gasoline vehicles are concentrated.

Global Warming
Carbon dioxide is a major by-product of fossil fuel combustion, and it is what scientists call a greenhouse gas. Greenhouse gases absorb solar heat reflected off the earth’s surface and retain this heat, keeping the earth warm and habitable for living organisms. Rapid industrialization through the 19th and 20th centuries, however, has resulted in increasing fossil fuel emissions, raising the percentage of carbon dioxide in the atmosphere by about 28 percent. This dramatic increase in carbon dioxide has led some scientists to predict a global warming scenario that could cause numerous environmental problems, including disrupted weather patterns and polar ice cap melting.

Although it is extremely difficult to attribute observed global temperature changes directly to fossil fuel combustion, some countries are working together to lower emissions of carbon dioxide from fossil fuels. One proposal is to establish a system requiring companies to pay to emit carbon dioxide above a specified level. This payment could take several forms, including: (1) purchasing the rights to pollute from a company whose carbon dioxide emissions fall below the specified level; (2) purchasing and then preserving forests, which absorb carbon dioxide; and (3) paying to upgrade a carbon dioxide emitting plant in a lesser-developed country, lowering the upgraded plant’s carbon dioxide emissions.

Petroleum Recovery and Transportation
Environmental problems are created by drilling oil wells and extracting fluids because the petroleum pumped up from deep reservoir rocks is often accompanied by large volumes of salt water. This brine contains numerous impurities, so it must either be injected back into the reservoir rocks or treated for safe surface disposal.

Petroleum usually must also be transported long distances by tanker or pipeline to reach a refinery. Transport of petroleum occasionally leads to accidental spills. Oil spills, especially in large volumes, can be detrimental to wildlife and habitat.

Coal Mining
Surface coal mining operations, often called strip mines, use massive shovels to remove soil and rock overlying the coal, disrupting the natural landscape. However, new land reclamation methods, driven by stringent laws and regulations, now require mining companies to restore strip-mined landscapes to nearly premined conditions.

Another environmental problem associated with coal mining occurs when freshly excavated coal beds are exposed to air. Sulfur-bearing compounds in the coal oxidize in the presence of water to form sulfuric acid. When this sulfuric acid solution, known as acid mine drainage, enters surface water and groundwater, it can be detrimental to water quality and aquatic life. Efforts are currently underway to remove sulfuric acid from mine drainage before it reaches rivers, lakes, and streams. For example, scientists are studying whether artificial wetlands have the ability to neutralize acid mine drainage.