'While oxygen (O2) is the second most abundant gas in our atmosphere, O2 does not absorb thermal infrared radiation,' Michael Daley, an associate professor of environmental science at Lasell College in Massachusetts, told Live Science. The most significant greenhouse gases, according to the Environmental Protection Agency (EPA), are: water vapor (H2O), carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). The greenhouse effect, in turn, is one of the leading causes of global warming. The gases in the atmosphere that absorb radiation are known as 'greenhouse gases' (abbreviated as GHG) because they are largely responsible for the greenhouse effect. How greenhouse gases cause global warming Weaker, longwave IR radiation, however, has difficulty passing through the glass walls and is thereby trapped inside, warming the greenhouse.

Incoming shortwave UV radiation easily passes through the glass walls of a greenhouse and is absorbed by the plants and hard surfaces inside. The exchange of incoming and outgoing radiation that warms the Earth is often referred to as the greenhouse effect because an agricultural greenhouse works in much the same way. Venus, on the other hand, has a very dense atmosphere that traps solar radiation the average temperature on Venus is about 864 F (462 C). The moon, which has almost no atmosphere, is about minus 243 F (minus 153 C) on its dark side. Without this atmospheric equilibrium, Earth would be as cold and lifeless as its moon, or as blazing hot as Venus. It's this equilibrium of incoming and outgoing radiation that makes the Earth habitable, with an average temperature of about 59 degrees Fahrenheit (15 degrees Celsius), according to NASA. The remaining 70% is absorbed by the oceans, the land and the atmosphere, according to NASA's Earth Observatory.Īs they heat up, the oceans, land and atmosphere release heat in the form of IR thermal radiation, which passes out of the atmosphere and into space. About 30% of the radiation that strikes Earth is reflected back out to space by clouds, ice and other reflective surfaces. UV radiation has a shorter wavelength and a higher energy level than visible light, while IR radiation has a longer wavelength and a weaker energy level. The greenhouse effect occurs because the sun bombards Earth with enormous amounts of radiation that strike Earth's atmosphere in the form of visible light, plus ultraviolet (UV), infrared (IR) and other types of radiation that are invisible to the human eye.

What is the greenhouse effect