The Greenhouse Effect and Climate Change
The earth is warmed when sunlight enters the Earth's atmosphere. Sunlight is partly absorbed by the Earth and partly reflected back towards outer space. The sunlight that is absorbed is later released as energy back into the atmosphere and then to outer space.
Certain gases in the atmosphere have the ability to absorb energy, hold it for a while and then release it at a later time. This is a natural effect and without it, Earth would be 33 deg C cooler and most plants and animals would not be able to survive. The more of these gases there are in the atmosphere the more energy they can hold. The effect is like insulating your home. It is commonly described as the greenhouse effect because of the way the temperature in a greenhouse is raised by the glass reflecting heat back inside rather than allowing it to escape. The energy takes longer to get back to outer space, so the temperature on Earth gets warmer.
The gases have been increasing in the atmosphere since humans developed agriculture and began clearing forests about 8000 years ago, and began rice irrigation about 5000 years ago. However the rate of gas production has dramatically increased since the industrial revolution began about one hundred and fifty years ago. About half of the gases are carbon dioxide and the rest is a mixture of methane, nitrous oxide and chlorofluorocarbons. These gases are the main contributors to global warming and are referred to as ‘greenhouse’ gases’. Many of them are found in nature, but are produced by man in such large quantities, that they have built up in the Earth's atmosphere.
Carbon dioxide has increased its concentration in the atmosphere by 34% since the beginning of the modern industrial era in the nineteenth century. About half of it comes from burning fossil fuels such as oil, coal and gas to produce energy for homes, offices, factories and transport and also from burning forests. Methane comes from agriculture, especially rice growing and the digestive processes of cattle, from coal mining, natural gas and from the breakdown of waste. Nitrogen oxides come from farming, fossil fuel and other materials. Natural factors such as volcanoes produce some of these gases, and variations in the sun's activities also contributes to global warming.
An exaggerated greenhouse effect has resulted in measured levels of global warming. This has manifested as a variety of unusual changes in the Earth's climate and more extreme climate changes are predicted. This is because even small increases in the Earth's temperature will cause many changes to the Earth's weather, including changes in rainfall, cloud distribution, wind patterns, rising sea levels and ocean currents.
What you can do
The most effective way to minimise your personal contribution to global warming is to reduce your energy consumption in as many ways as possible. By using less fuel, natural gas, oil and electricity in your daily life, you reduce the burden for energy production, and set an example for others to follow. Your choices about energy and transportation are especially important.
Below are some of the things you can do to reduce greenhouse emissions and save money:
If you are buying a new car choose one that is highly fuel efficient. Compare the fuel economy of the cars you're considering and look for new technologies like hybrid engines.
Instead of driving alone in your car, join a carpool, take public transport such as buses or trains, walk, or ride a bike.
Get your car tuned up. A simple tune-up may improve fuel efficiency by half. If 100,000 of us went out and got a tune-up, we would save 124,000 tons of CO2.
The next time you buy an appliance, purchase a highly efficient mode. Refrigerators, freezers, furnaces, air conditioners and water heaters use the most energy, so look for the Energy Star label on these appliances. Appliances with this label will cost you less to run and because they are energy efficient they will use less electricity.
Ask your local electric or gas utility to perform an energy audit of your house or apartment. Then put the recommendations into practice. Simple measures, such as installing a programmable thermostat to replace your old dial unit or sealing and insulating heating and cooling ducts, can each reduce a typical family's carbon dioxide emissions by about 5 percent.
Choose clean power. A large percentage of electricity in the world comes from polluting coal-fired power plants. None of us can live without electricity, but in some countries it is possible to switch to electricity companies that provide 50 to 100 percent renewable energy. Many utilities now give consumers the option to buy green power so ask for it!
Unplug your extra freezer when you are not using it. This can reduce the typical family's CO2 emissions by nearly 10 percent. Older refrigerators, as a rule, are far less efficient than the newest ones – as much as 50 percent less efficient in many cases. Make sure the doors seal properly, and make sure you don't set the thermostat too high as this will cause your refrigerator to use more electricity than necessary.
Use energy saving devices such as efficient light bulbs. There are now highly efficient fluorescent light bulbs (CFLs) that use a quarter of the energy of regular incandescent light bulbs and actually produce more light.
Use less energy for example, by turning off lights that are not required or by bringing natural sunlight into your home.
When buying wood products, check for labels that indicate the source of the timber. Forests that are well managed are more likely to store carbon effectively because more trees are left standing and carbon-storing soils are less disturbed.
As most of the increase in atmospheric carbon dioxide comes from the burning of fossil fuels, do whatever you can to reduce your reliance them. Fossil fuels are used in construction of just about anything you can buy. So basically reduce your use of all products. Reuse everything you can and recycle anything you cannot reuse. Buy recycled products. It takes less energy to manufacture a recycled product than a brand new one. If you and every other consumer buy recycled goods, you will help create a market, and conserve energy along the way.
Write a letter or email your local newspaper about the significance of the global warming threat and the need for reduced greenhouse gas emissions.
Write a letter or email to the government ministers of your country and ask them to address the root causes of global warming, the emission of heat-trapping greenhouse gases, and to look at using alternative energy or sequestering carbon. Tell them that you want them to make industry reduce carbon emissions.
Deforestation and the accompanying loss of organic matter from soil have contributed to increased carbon dioxide in the atmosphere. As all plants use carbon dioxide from the air for photosynthesis, the more plant matter there is, the less carbon dioxide there is in the air. Support efforts to increase the amount of forests or to reverse land degradation. Plant more trees in your community and encourage others to do the same. In addition to storing carbon, trees planted in and around urban areas and residences can provide much needed shade in the summer, reducing energy bills and fossil fuel use.
Use the most appropriate building materials and design for your home, depending on the climate. Wherever possible use solar powered technology. If this is not available, the energy sources which have the least greenhouse impact are natural gas and LPG.
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