The Greenhouse Effect

Gases in the atmosphereThe change that is now taking place in the global climate has its roots in the intensification of a natural phenomenon, the greenhouse effect. The atmosphere is made up of water vapour, dust particles and gases. The main gases are nitrogen (78 per cent) and oxygen (21 per cent). Argon, and small amounts of other gases, such as carbon dioxide and trace amounts of hydrogen, methane, ozone, carbon monoxide, helium, neon, krypton and xenon account for the remaining 1 per cent.


However, some of the gases in this 1 per cent play an important role in regulating the Earth’s temperature by helping to balance the energy that is received from the sun and reflected back into space by the Earth. These gases include carbon dioxide, methane, and nitrous oxide and, together with The greenhouse effectwater vapour, are commonly known as greenhouse gases. They help warm the atmosphere by trapping some of the energy reflected off the Earth and preventing it from escaping.


The principle is much like the heat-trapping glass panels of a greenhouse, hence the name greenhouse gases.  The glass panels of a greenhouse allow radiation from the sun to get in, but prevent the heat that is generated by the ground, plants and objects inside from escaping easily. The result is a build-up of heat inside. The greenhouse effect works much the same way. Energy from the sun, or solar radiation, passes through the atmosphere and warms the Earth’s surface. Some of the radiation is reflected back out into space at the level of the atmosphere. Some reaches the Earth, is absorbed by the ground and released as heat. Some of this heat passes back through the atmosphere into outer space and some is retained by the gases in the atmosphere and warms the Earth. Greenhouse effect - Source Impetus Consulting LTD


The problem of climate change is caused by emissions of greenhouse gases which have enhanced the greenhouse effect.
This natural warming is what makes the Earth habitable for the plants, animals and humans that have evolved there; without it, the Earth’s average temperature would be an inhospitable -18°C instead of the present 14°C.