How does the energy we consume affect the environment?

The term global warming may be something you are already familiar with: it is an increase in temperature is a result of the greenhouse effect. Some scientists believe that greenhouse gases such as carbon dioxide are trapped in the Earth’s atmosphere, increasing the temperature on Earth. Burning fossil fuels and other pollutants that have been released into the atmosphere may cause these greenhouse gases.

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Even the slightest change in the earth’s temperature is significant, and if it carries on increasing it could have a serious effect on the Earth’s polar caps (the north and south pole). Hotter temperatures may result in some of the ice melting, which in turn could raise the sea levels, causing some land to be covered by sea. It is predicted that in the next 100 years, the Earth’s temperature will increase by anything between 1-2°C. Again, this might not seem like very much, but if we consider the Ice-Age (18,000 years ago) the temperature was only 10-12°C less than it is now and the earth was covered in ice!

Discuss it ... What do you think would happen to plants and wildlife if the earth’s temperature increases?
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Burning fossil fuels raises important questions about our source of energy: the amount fossil fuels on the Earth will not last forever, and burning fossil fuels releases carbon dioxide. There is also risk of oil spills, making air quality poor, and acid rain. Also, since they are non-renewable fossil fuels are extremely valuable!

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What can we use instead of fossil fuels?

If the supply of oil is running out, and natural gas is quickly following, where do you think our energy will come from in the future? Scientists are looking at ways of using renewable energy sources, that’s things like the sun, wind or water. There are lots of different sources of energy.

People have actually used wind as a source of energy to power things for thousands of years! As long ago as 5000 BC sails were used to travel down the Nile, and windmills were used by the Persians to move water and grind grain, maybe as long as 1,500 years ago!

Discuss it ... What are the problems of using wind as a source of energy?

Solar power is another good source of energy, plus it is free! Already systems have been developed to use the energy from the sun to make electricity and heat.

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Discuss it ... What do you think about using the sun as a source of energy? Are there any environmental risks?

Sunshine can be just as unpredictable as wind, and the equipment needed to convert it into a useable form can be very expensive, but the more we use it, the cheaper it will be.

Water is also a very old source of energy. Thousands of years ago the Greeks used water wheels that used the weight of water to move machinery to grind grain and pump water. We now use man-made dams that maximize this source of energy. Today, about one fifth of the energy we use comes from the energy from falling water.

Organic matter can be a source of energy too. In the last ten years it has become a widely used source: 15% of the world’s energy comes from biomass, which is the energy that comes from the breakdown of organic matter e.g. burning wood. It would not be possible to create all of the world’s energy needs from this source alone, but it is an alternative to fossil fuels.

Discuss it ... How do you think burning wood affects the environment?

Hydrogen is one of the most common elements in the universe. Scientists have recently developed a method of using it to produce gas and oil. Fuel cells have been developed which can power cars, lorries and even rockets. The plus side of using hydrogen is that the by-product is harmless – water! With advances in technology, it is believed that fuel cells in the future might even clean the air!

Geothermal energy is the heat energy that comes from the earth, and this is a heat so intense that it can create molten magma (think about volcanoes!). If generators are place near to a source such as a geyser, we can use the heat from the earth to produce hot water or electricity. This power source is renewable.

Discuss it ... What do you think would happen if the steam from a geyser was used faster than it was produced?

What about electric cars?

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We use a lot of cars and lorries! They use a lot of fossil fuels and produce exhaust fumes that pollute the atmosphere.

Discuss it ... Since cars powered by electricity produce no pollution, why doesn’t everybody drive an electric car?

Petrol is relatively efficient as a source of energy to power things: it holds a lot of potential energy. To power some electric cars you’d need a battery - chemical energy - which would be extremely heavy when compared to the equivalent amount of petrol.

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Petrol is also fairly inexpensive to produce, and is relatively easy to store because it’s a liquid. Most petrol cars can drive for about 480 – 640km on a full tank of petrol. An electric vehicle gets only about 100 miles to each charged battery and it can take hours to fully recharge it again.

Discuss it ... Do you think we’ll all be using electric cars in 100 years time – even Michael Schumacher?

Despite all of this, electric cars are more environmentally friendly than petrol cars. Scientists are working very hard as you read this to come up with new alternatives to supply the increasing amount of energy we need!

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