What are greenhouse gases?
Greenhouse gases are naturally occurring gases in the atmosphere that have the capacity to absorb long-wave radiation emanating from the Earth’s surface. By absorbing this energy and re-radiating it, the gases cause the temperature of the Earth’s lower atmosphere and surface to increase. The most common greenhouse gases are water vapour and carbon dioxide. Others include methane and nitrous oxide. Man’s activities have increased concentrations of all of these gases and have also introduced new ones, such as CFCs.
Some atmospheric gases, like Carbon dioxide (CO2) trap the sun’s heat against the Earth, the same way a greenhouse magnifies the sun’s heat to grow plants. These gases come from burning coal, natural gas and oil – fossil fuels – to make energy. This blanket of gas traps the sun’s energy so that it can’t escape beyond our atmosphere. If the Earth were too cold, humans could not survive, so some greenhouse gas cover is necessary and natural. But we are burning fossil fuels at such an extreme rate that the blanket of greenhouse gases is thickening to the point at which our planet is quickly heating beyond the healthy range.
Greenhouse gases are gases that can absorb the thermal energy emitted by the earth, creating the greenhouse effect, which warms the earth. There are approximately 30 gases that qualify as climate-changing greenhouse gases, these gases have been chosen due to their Global Warming Potential (GWP) and the quantity in which they are released. GWP is the concentration of the gas and is measured compared to carbon dioxide, for example, methane has 30 times the global warming potential of carbon dioxide. The six greenhouse gases specified in the Kyoto Protocol are: • Carbon dioxide (CO2) – The main causes of this increase are the burning of fossil fuels (oil, coal and natural gas) to create electricity and to produce fuel for transport. • Methane (CH4) – The main causes of this increase come from the digestive processes of livestock, the cultivation of rice, escaping natural gas and decomposing waste in garbage dumps or landfills. • Nitrous oxide (N20) – The main causes of this increase come
By preventing longwave radiation from leaving the earth’s atmosphere, greenhouse gases trap energy and keep our planet warm. The most common greenhouse gases are water vapor and carbon dioxide (CO2). Methane (CH4), nitrous oxide (N2O), ozone (O3), and halocarbons such as chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs) also contribute to the greenhouse effect by trapping infrared energy. While many of these gases occur naturally in the atmosphere, their concentrations have increased dramatically since the Industrial Revolution as a result of burning fossil fuel.
