The Greenhouse Effect

The greenhouse effect is a phenomenon which is essential to life on earth. It is caused when solar radiation penetrates the earth’s lower atmosphere and reaches the earth’s surface, where is converted into heat and reflected back towards space in the form of infrared radiation. Unlike incoming solar radiation however, much of the reflected infrared radiation becomes trapped by gases in the earth’s atmosphere. These gases are collectively referred to as “greenhouse gases”, and it is the atmosphere’s retention of infrared radiation by these gases that causes our atmosphere to retain the heat which makes life on earth possible.

The earth’s greenhouse effect is caused by naturally occurring greenhouse gases. Carbon dioxide for example, is one of the most abundant natural gasses in the atmosphere and it plays an important role in essential plant and animal processes, such as photosynthesis and respiration. In order to understand the important role of carbon in our environment, is necessary to understand the carbon cycle.

The reason that the greenhouse effect has recently become a topic of tremendous concern, is that for the last 150 years or so, human beings have been producing greenhouse gasses—mostly carbon emission via industrial processes—at rates beyond the earth’s biomass’s natural capacity to absorb them. This has led to unnaturally high concentrations of greenhouse gasses in our atmosphere

Recent increases in greenhouse gas concentrations resulting from human emissions of carbon dioxide, methane, nitrogen oxides and Chlorofluorocarbons (CFC's) are believed to have ca used increases in the atmospheric retention of infrared radiation. It is this excess retention of infrared radiation that is believed to be the cause of recently observed increases in the earth’s average surface temperature, an increase commonly referred to as global warming.