Greenhouse gases are vital in order to maintain a temperate environment for us to live on Earth. Under normal conditions, the sun’s energy enters the atmosphere and warms the surface of the Earth. Some of this energy is re-radiated back to space in the form of infrared waves. Typically, some of the outgoing infrared rays are trapped by the greenhouse gases in the Earth’s atmosphere keeping our air temperature moderate. However, as the level of carbon dioxide (CO2) has increased in the Earth’s atmosphere due to human activity, more and more infrared rays are being trapped. Consequently, we are experiencing warmer conditions.

Carbon Dioxide (CO2)
When we talk about greenhouses gases, most people assume we are talking about carbon dioxide because it accounts for more than 80% of the greenhouse gas emissions. CO2 is emitted primarily through the burning of fossil fuels (oil, natural gas and coal), solid waste, and trees and through the production of cement. Additionally, as we continue to cut and burn forests, not only are we emitting more CO2 into the atmosphere, but we are also eliminating the trees and vegetation that help absorb the CO2 in the air.

Methane (CH4)
Methane is emitted through the production and transport of oil, natural gas and coal. Methane emissions are also the result of landfills, livestock and agricultural farming.

Nitrous Oxide (N2O)
Nitrous Oxide emissions are caused by the burning of fossil fuels and solid waste, deforestation and fertilizers.

Fluorinated Gases (SF6, PFCs and HFCs)
Unlike the other greenhouse gases that exist naturally in the earth’s atmosphere, fluorinated gases are produced exclusively through human activity. These gases are emitted in smaller quantities, but are much more potent and frequently referred to as High Global Warming Potential gases (“High GWP gases”). HFCs have replaced CFCs which were originally used in refrigeration systems, solvents, aerosol propellants and elsewhere, but were depleting the ozone layer. SF6 and PFCs are released into the atmosphere by a variety of industrial processes.

Source: www.epa.gov/climatechange

 

 

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