Ever since the Industrial Revolution, human activities have constantly changed the natural composition of Earth’s atmosphere. Concentrations of trace atmospheric gases, nowadays termed “greenhouse gases,” are increasing at an alarming rate. There is conclusive evidence that the consumption of fossil fuels, the conversion of forests to agricultural land, and the emission of industrial chemicals are the principal contributing factors to air pollution.

According to the National Academy of Sciences, the Earth’s surface temperature has risen by about 1 degree Fahrenheit in the past century, with accelerated warming occurring in the past three decades. According to statistical reviews of the atmospheric and climatic records there is substantial evidence that global warming over the past 50 years is directly attributable to human activities.

Under normal atmospheric conditions, energy from the Sun controls the Earth’s weather and climate patterns. Heating of the Earth’s surface resulting from the Sun radiates energy back into space. Atmospheric greenhouse gases, including carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), troposphere ozone (O3), and water vapor (H2O), trap some of this outgoing energy, retaining it in the form of heat, somewhat like a glass dome. This process is referred to as the GREENHOUSE EFFECT.