Environmental Impacts of Fossil Fuel Use
Effects that fossil fuels have on the environment
A fossil fuel is formed by natural processes. It contains energy originating from the photosynthesis from the ancient period. Fossil fuels include coal, natural gas, petroleum, bitumen and they all contain high percentages of carbon, but also hydrogen and oxygen. In addition, these fuels contain other components like some metal, sulfur or nitrogen compounds. Most of our transportation, heating, and operation of power plants depends on the combustion of coal, oil (and its products) or natural gas. The most significant harmful effects of fossil fuels combustion on the environment are: thermal pollution, chemical (particulate) pollution and the effect of greenhouse gases.
During fossil fuels combustion, a certain amount of heat is released to the environment, because of thermodynamic constraints. The mechanisms for overcoming this ecological problem include the existence of a larger amount of water and cooling towers, as well as by using dry heat exchangers. The consequences of such treatments include an increase of oxygen levels in water, a change in the rate of chemical reactions, a rise in humidity, or the occurrence of fog near the cooling towers. Combustion of fossil fuels releases various chemical compounds, named pollutants, such as oxides, ash, and volatile organic compounds. By combustion of fossil fuels, sulfur, nitrogen and hydrogen are released, which create oxides with oxygen. The released oxides of sulfur and nitrogen are further oxidized in the presence of water vapor, fog and water droplets, producing sulfuric (H2SO4) and nitric (HNO3) acid. Condensed atmospheric water vapor with this acidic content, known as acid rain, enters the water circulation and harmfully affects the environment. The freed ash formed by fossil fuels combustion contains different trace elements, most commonly heavy metals (e.g. mercury). It has been shown that volatile organic compounds make damage to the stratosphere, lead to the greenhouse effect, impair human health, etc.
Carbon dioxide (CO2) is the main by-product of fossil fuels combustion, which also called “greenhouse gas”. Other gases that belong to this group are: water vapor H2O (90%), nitrogen suboxide (N2O), methane (CH4), hydrofluorocarbon (HFC), etc. They all absorb solar energy emitted from Earth’s surface and retain heat. These substances have a long half-life period in the atmosphere and therefore have a global role in environmental pollution. The dramatic increase of the CO2 presence in the air has formed scientific assumptions that predict the consequences of global warming will be climate changes (constant melting of glaciers and sea ice, with the largest warming in the Arctic).
All these pollutants are present in the atmosphere and in various ways have a detrimental effect on human health and the environment. Airborne pollution caused by particles and other pollutants, besides direct environmental impact, affects pollution of water and soil. Many plants, especially conifers, are not resistant to oxide compounds from the air. The long-term exposure triggers drying and leaf-fall. Destruction of the entire forests is very expressed in Europe and North America. Also, cultivated plants are very sensitive to air pollutants, especially during the early vegetative period. Moist and dry deposits of inorganic pollutants lead to acidification of the environment, which further impair human and animals health, destroys forests and cultivated land, and increases corrosion. Surface mine pits and underground mines lead to the creation of landfills and ash dumps. They are usually formed on arable land and directly or indirectly endanger biodiversity of the entire area. Besides the described harmful effects of fossil fuels combustion, ecological problems are also created by oil wells operation. In addition to crude oil extracted from deep underground reservoirs, sea water polluted by numerous impurities are also extracted. It is necessary to carry out the injection of such water back into the tanks or perform its adequate purification for the purpose of safe surface disposal. Transportation of crude oil often causes unwanted leaks due to pipelines failure or tanker accidents. The oil spills, especially those of large-scale, can be extremely harmful to natural habitats and biodiversity.
According to the research from 2015, motor vehicles are listed as the largest source of hydrocarbon pollution (HC) (35%), release of carbon monoxide (CO) (60%), emissions of mono-nitrogen oxides (NOx) (35%) and sulfur dioxide (SO2) (65%).
Reducing the negative impact of vehicles on the environment is achieved through numerous constructive and technological innovations that need to be applied. An example of a technological process that aims to reduce the negative impact of combustion in vehicles is to clean the engine with hydrogen.