The Little Things Count

The greenhouse effect is a natural effect that causes the Earth’s atmosphere to be about 33°C warmer than it would be without the layer of greenhouse gases. These gases allow short-wave radiation from the sun to be transmitted to the Earth’s surface but prevent long-wave radiation from leaving the atmosphere. The gases also absorb the heat from the ground, heat up and then re-radiate the extra warmth back down to the Earth’s surface.

There are a number of gases that contribute to the natural greenhouse effect.
Water Vapour, although subject to wide fluctuations, does have an enormous long-term effect. E.g. Clouds composed of large amounts of water vapour, reduce heating by day by cutting out the suns radiation, and reduce cooling by night by preventing the escape of long-wave radiation.
Carbon Dioxide is released as a result of respiration and decay.
Methane is released by bacteria during the anaerobic decay of many types of organic matter. Some methane has become trapped beneath the ground, especially in conjunction with coal.
Nitrous Oxide (N2O) is released as a result of bacterial activity in soils and the oceans.


There is strong evidence that the pace of global climate change in increasing and that this correlates with the increase in greenhouse gas emissions as a result of human activities (industrialisation).
The concentration of the following gases has been increased by anthropogenic means.
Carbon Dioxide is mostly produced through the burning of fossil fuels. Fossil fuels contain large amounts of carbon that were locked away millions of years ago. Burning these involves oxidation of the carbon, thus it releases carbon dioxide in the air much faster than it can be locked away. Deforestation means not only that there are fewer trees to absorb CO2; but also that additional CO2 is released into the atmosphere when the wood decomposes or burns.

Methane has a greater greenhouse effect. Anaerobic bacteria produce large amounts: in paddy fields, which are flooded during the establishment phase of a rice crop; in landfill sites; and by cattle during the digestion of cellulose. Methane is also released during the ventilation of coalmines, leaks from pipelines and natural gas fields.

Nitrogen Oxides are mostly released into the atmosphere from burning petrol and diesel fuel for transport but some also come from the burning of fossil fuels in power stations, and the production and use of nitrogen fertilisers.

Chlorofluorocarbons (CFCs) are entirely anthropogenic the have been manufactured for use as aerosol propellants, refrigerants, and solvents, in fire extinguishers and to make expanded plastics such as foam.

Low-level (tropospheric) ozone is produced by photochemical reactions between nitrogen dioxide and non-methane hydrocarbons (NHMC) from vehicle exhausts. NHMC also act as greenhouse gases themselves.