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The greenhouse effect is the process by which energy from the sun is trapped in the form of heat close to the Earth by various types of gas.
Although the Sun is very hot, the energy that reaches the Earth is visible and ultraviolet light radiation. This light energy hits the Earth or clouds and converts into lower-energy infrared radiation. That energy then begins to move away from the Earth back into space and without greenhouse gasses, it would be lost. Greenhouse gasses absorb infrared radiation and convert it to heat energy, holding it mostly in the troposphere. This is a vital process that keeps the Earth warm enough for life to exist. Without these gasses converting and trapping energy close to Earth's surface, it would be too cold for modern life to exist.
Certain gasses have a higher thermal retention property, meaning that they are able to hold onto heat energy at a greater rate than others. These gases are often called greenhouse gasses.
· Carbon dioxide
· Water vapor
· Nitrous oxide
· Chlorofluorocarbons (CFCs).
The global warming potential (GWP) of a gas is used to distinguish its potential impact on global climate change. GWP estimates how much a molecule of any compound could contribute to global warming within 100 years, in comparison to carbon dioxide. Carbon dioxide has a GWP of 1 and is often used as a comparison point for other glasses. Chlorofluorocarbons (CFCs) have the highest GWP (13,000), followed by nitrous oxide (300), then methane (25).
Sources of Greenhouse Gases
Volcanic eruptions: A large amount of CO2 and ash released can have significant short term effects on climate. Historic large scale eruptions have been at fault for reducing the global average temperature from blocking solar ration.
Carbon dioxide: Carbon dioxide naturally occurs as a byproduct of metabolic reactions. The brut Combustion of fossil fuels.
Methane: Decomposition under low oxygen conditions produces methane. This naturally occurs in environments like wetlands and in the guts of animals. The increase in cattle farming created a large scale global increase in methane production.
Nitrous oxide: Is naturally produced in the process of denitrification, coming mostly from low oxygen environments like wetlands and the ocean. Humans have increased the production of Nitrous oxide with the combustion of fossil fuels, especially the burning of coal for electric power generation and the addition of excess nitrates as fertilizers.
Chlorofluorocarbons (CFCs): Man made aerosol propellant with very high GWP. These chemicals were phased out by countries under the Montreal Protocol due to their ozone depleting capabilities. They were replaced with hydrofluorocarbons (HFCs), reversing ozone damage but still contributing to increased greenhouse effect.