Particularly for large metropolitan cities, smog and poor air quality is a pressing environmental problem. Smog primarily consists of carbon monoxide, nitrogen oxides, volatile organic compounds chemically interacting with heat from sunlight forming ground level ozone. Smog is that familiar haze most commonly found surrounding large cities, particularly in the summer time. Smog and ground level ozone contribute to all kinds of respiratory problems ranging from temporary discomfort, asthma, to long-lasting, permanent lung damage. The pollutants in smog come from vehicle emissions, smokestack emissions, paints, and solvents - most of which started out as crude oil.
Much of the eastern United States is affected by another environmental problem known as acid rain. Acid rain can damage crops, forests, wildlife populations, and cause respiratory and other illnesses in humans. When sulfur dioxide and nitrogen oxides react with water vapor and other chemicals in the presence of sunlight, various acidic compounds form in the air and come to the earth as acid rain. The pollutants of acid rain are derived from coal fired power plants. Natural gas emits virtually no sulfur dioxide and up to 80 percent less nitrogen oxides than the combustion of coal. So the increased use of natural gas would provide for fewer acid rain causing emissions.
The source of energy to use for reducing pollution and maintaining a clean and healthy environment is natural gas. Natural gas is also domestically abundant making it a secure source of energy. The environmental benefits of using natural gas over other sources of energy, particularly other fossil fuels are numerous.
Since the use of natural gas emits only low levels of nitrogen oxides and virtually no particulate matter, it can be used to help combat smog formation in those areas where ground level air quality is poor. Electric utilities, motor vehicles, and industrial plants make up the main sources of nitrogen oxides. To combat smog production, especially in urban centers where it is needed the most, increased natural gas use in the electric generation sector, a shift to cleaner natural gas vehicles, and increased industrial natural gas use could all serve to improving the air quality. Summertime, when natural gas demand is at its lowest and smog problems are the greatest, would be a good time for industrial plants and electric generators to use natural gas to fuel their operations instead of using the more polluting fossil fuels. This would effectively reduce smog emissions resulting in clearer, healthier air around the urban centers.
A study conducted in 1995 by the Coalition for Gas-Based Environmental Solutions found that in the Northeast, smog and ozone-causing emissions could be reduced by 50 to 70 percent through the seasonal switching to natural gas.
Particulate emissions such as soot, ash, metals, and other airborne particles also cause the degradation of air quality in the United States. Natural gas emits virtually no particulates into the atmosphere. Emissions of particulates from natural gas combustion are 90 percent lower than from the combustion of oil, and 99 percent lower than burning coal. Increased natural gas use in place of other dirtier hydrocarbons can help to reduce particulate emissions in the United States.