"Fact Sheet THE GREENHOUSE EFFECT"
Fact Sheet THE GREENHOUSE EFFECT The “Greenhouse Effect” is a natural phenomenon which has been operating for billions of years and without it the average temperature of the earth’s surface would be about the same as the North Pole (about 30 degrees colder). The earth atmosphere contains a blanket of naturally occurring gases which act like an enormous glass window. While allowing most of the sun’s energy to pass through and warm the earth’s surface, these greenhouse gases also trap some of the heat given off by the earth’s surface, maintaining temperatures at life sustaining levels. INCREASING GREENHOUSE EMISSIONS Within the past few hundred years, human activities have increased the concentrations of greenhouse gases in the atmosphere. Some scientists predict that increasing the amount of greenhouse gases will trap too much heat causing the temperature of the earth to rise between 0.2 to 0.5 degrees per decade if action is not taken. • The possible changes likely to occur are; 1. Sea levels may rise due to melting of polar ice caps. This may result in low lying areas disappearing, eg Islands such as the Maldives. 2. Less fresh water being available as evaporation of lakes and rivers will increase and plants would lose more water by transpiration. 3 Changes in weather patterns may affect agriculture, impact on pests, parasites and tropical diseases. 4. Globally there will be more droughts, with semi-desert areas becoming deserts. 5. All of these changes will impact on ecosystems and affect plants and animals in these area, as they are very sensitive to temperature changes, eg. Some species may become extinct, while others may increase. AUSTRALIA’S CONTRIBUTION TO THE GREENHOUSE EFFECT • Every year, Australia produces almost 300 million tonnes of carbon dioxide, the main greenhouse gas. Other greenhouse gases we produce include methane, nitrous oxide and chlorofluorocarbons (CFC’s) which increase our total greenhouse impact to about 500 million tonnes. • This is around 30 tonnes of greenhouse gas each year for every Australian, which is five times the world average. Garry Meusburger April 2000 THE MAIN SOURCES OF GREENHOUSE GASES 1. CARBON DIOXIDE (approx 54% of all emissions of greenhouse gas) is produced mainly by burning oil, gas, coal, wood or waste materials, in particular in the production of electricity and use of motor vehicles. 2. METHANE emissions arise from the production and distribution of fossil fuels, landfill sites and ruminant animals. 3.NITROUS OXIDE is produced in small amounts by burning coal, gas, oil or plant material, however most is released by soil cultivation and spreading of nitrogen fertilisers. 4. CFC’s Chlorofluorocarbons are used in most air conditioners and refrigerators, in aerosols and manufacturing processes, although the volume of CFC’s in use today has declined dramatically due to recent legislation. SO WHAT CAN WE DO? We can all make a difference and in many cases, reducing greenhouse emissions will save money, increase your exercise and improve your comfort. DO’S • Reduce energy consumption in the house. Examples include turning off lights and appliances not being used, purchase energy efficient appliances including light bulbs, fridges, dryers etc., and wearing warmer clothing in winter. • Insulating your homes to reduce the use of cooling and heating appliances. • Ride a bike, walk or use public transport rather than driving a car. • Make sure your car is regularly serviced to run efficiently. Smaller cars are preferred as they burn less fuel. • Use solar power as an alternative to electricity. • Plant a tree or garden - this helps reduce carbon dioxide levels as trees absorb carbon dioxide to produce oxygen (photosynthesis). • Recycle or reuse your waste where possible, such as glass, paper, metal and plastic. This reduces energy required to manufacture new products, reduces landfill and conserves resources (trees etc,). DON’TS • Burn off rubbish. This is illegal in the Wollongong local government area. • Buy products with too much packaging - this wastes energy and resource materials. • Repair or re-gas your car air conditioning unless it is carried out professionally to prevent the escape of the residue gas.