Climate change is caused by the increase of greenhouse gases in the atmosphere. The three main greenhouse gases are carbon dioxide, methane and nitrous oxide.
Greenhouses gases
Heat from the sun is usually reflected back into space by planets such as Earth, but the layer of greenhouse gases traps some of the heat and then radiates it back to warm Earth. This effect keeps the Earth roughly 33 (need degree C sign!) warmer than it would be without an atmosphere. If this did not happen we would not exist.
However, the problem today is that the amount of greenhouse gases in the atmosphere is increasing. As a result, more heat is being trapped in the atmosphere, and the overall temperature of the Earth is increasing. Since 1900 average world temperatures have risen by up to .6 and nine our of ten of the hottest years on record have occurred since 1983. This increase in world temperature has led to a rise in the sea level of 10 to 25cm since the late 19th Century. In the UK, sea level is expected to rise by 5cm per decade, threatening low lying coastal land and cities.
Effects of climate change
We are already seeing the effects of climate change through the increased occurrences of major flooding throughout the country and major storms with gale force winds. Most tragically throughout the world major disasters such as the 2004 Asian Tsunami have been attributed to the effects of climate change.
Carbon dioxide
The most abundant greenhouse gas is carbon dioxide. The increased levels of carbon dioxide in the atmosphere are produced by burning of fossil fuels (coal, oil and gas). They all contain carbon and produce carbon dioxide when they are burnt. The more fossil fuels that are burnt the greater the amount of carbon dioxide in the atmosphere.
Power stations produce about 27% of the UK’s carbon dioxide emissions. The Government had therefore proposed that a target of 10% electricity is to be generated by renewables (wind turbines, solar power etc) by 2010.
The other way to reduce greenhouse gases is by energy efficiency measures whether in the home or by looking at our transport and lifestyle choices. For example, we can insulate our homes so we do not let the heat escape as easily. Therefore we need less heat to maintain the temperature in them and consequently burn less fossil fuels. We can use our behaviour to restrict the amount of fuel we use, for example, not leaving out tv’s and stereos on standby (this still uses up to 70% of the electricity if they were on ), only putting the amount of water we intend to use in the kettle, turn lights off when we leave a room, put the plug in a sink when washing.
