What is the Greenhouse Effect?

The greenhouse effect is term that has become synonymous with the increase in global temperature as a result of human activities. However, the greenhouse effect is an entirely natural process which crucially allows the Earth to retain the warmth it receives from the sun. Without the natural process of the greenhouse effect the earth would be a much colder and vastly different place than it is today!

The earth receives warmth from the sun, some warms the earth’s surface and some is radiated back into the atmosphere where some of it is absorbed by greenhouse gases. The gases that absorb this heat energy then release it in all directions, and about a third of it heads back towards Earth. Basically, the atmosphere and the greenhouse gases within it act as a blanket to keep the Earth warm.

The problem is that we now pollute the atmosphere with extra greenhouse gases. This means that there are more gases in the atmosphere that are capable of capturing and returning the heat energy radiated from the earth and this is resulting in increasing global temperatures. This is commonly known as global warming.

What are greenhouse gases?

There are four main naturally occurring greenhouse gases that are necessary for the greenhouse effect : water vapour, carbon dioxide, methane and nitrous oxide.

Carbon dioxide tends to be the gas that we hear about most today. It is released when we burn fossil fuels such as coal and gas. The fuels we burn in cars and machinery and to produce electricity also release carbon dioxide into the atmosphere. Deforestation is another major contributor to carbon dioxide levels as the trees themselves absorb CO2 when they are growing which helps to balance atmospheric levels, however, if they are burnt this releases the CO2 rapidly back into the atmosphere.