Read the two articles carefully and answer the questions that follow each article. Use your own words throughout as far as possible.

If creatures from another planet1 have been monitoring1 Earth for several centuries, they must have been puzzled by changes in recent times. During the 20th century, they would have noticed that increasingly larger parts of Earth became noticeably brighter, except for the period 1039–45, when many of them suddenly became dimmer2 (during the blackout of World War II). Then from 1945 onwards, the lights returned and continued to spread across Earth.

If the same scientists are still observing Earth, another puzzle awaits them since it is highly likely that the lights will become dimmer as this century progresses. The sources which provide us with light and energy are dwindling at the same time as the demand for them increases. The oil wells of the USA and the North Sea are almost exhausted. The price of fuel from remaining sources has risen by around 100% and new sources are inadequate to meet demands. Coal mines are out of favour because of the pollution which coal creates when it is burnt to supply power. The supply of electricity from hydroelectricity is severely limited. Geothermal sources have not been widely utilised and make little contribution except in a few places.

Meanwhile, the shortage of supplies of energy is accompanied by greatly increased demands for oil, gas, and electricity. At one time, a single home might be lit by one or more simple oil lamps. In the past century, the number of homes has multiplied at a steadily increasing rate and electricity is needed for lights, air-conditioners or central heating (depending on where the homes are located), for television and computers, and to power equipment used for cooking, ironing, and repairs to the home.

In the streets outside the homes, electricity is needed for street-lightning and for the horde of advertising signs found in every modern city. Cars, buses, lorries, and vans rely on petrol or diesel oil to enable them to move. The number of vehicles on the road in China, Japan, Europe, and the Americas is increasing daily and shows no sign of falling while the never-ending increase in the price of fuel reflects the awareness of suppliers that their sources are gradually being depleted. At the same time, industrialisation has brought with it countless factories which require huge quantities of electricity to enable them to function.

A further need for electricity is found in the number of schools, hospitals, and public buildings which have come into existence in the last century. Compulsory education (and an increase in the school-leaving age) has meant that thousands of new schools have had to be built. Improvements in health services have led to the creation of large new hospitals and many small clinics, all of which need a considerable amount of electricity.

Centuries ago, people rarely moved beyond their village. If they did move, they had to walk or ride on an animal such as a horse, camel, or donkey. In modern times both goods are on the move constantly. Ships carry vital goods or cruise passengers around the world ceaselessly. The number of planes has risen dramatically, enabling tourists (as well as businessmen) to visit foreign countries as frequently as they like. Both ships and planes consume huge quantities of fuel oil. Each new ship or plane increases the burden on suppliers and forces up the price.

If we set greatly increased demand (from homes, industry, and travel) against steadily dwindling supplies, it become highly likely that scientists from that distant planet may soon be asking each other why the lights on Earth have started to become dimmer again.

An increasingly familiar theme in all industrialised country is the need to conserve energy and to find alternative methods of producing energy. Conservation involves saving energy by using as little as possible. Energy saving light bulbs are becoming increasingly popular and in some countries are being given away by local authorities as a means of making them more popular. A 20-watt energy-saving lamp can last ten times as long as  an ordinary one, produce as much light as an ordinary 100-watt lamp and use only 20% of the energy of the conventional lamp that it replaces. In the UK, conventional light bulbs will soon become illegal and will have to be replaced by energy-saving ones.

At the moment, nuclear plants are seen as an alternative to oil and gas  a way of producing electricity but these plants can be dangerous as the explosion at Chernobyl showed. There is always a danger that an accident at one of the plants can lead to the release of massive doses of radioactive dust which can be carried on the prevailing wind and kill any living thing in their path. Even if the nuclear plants are made safe, the problem of disposing of increasing piles of radioactive waste is one for which no entirely satisfactory solution has been found.

When we turn to safer alternative ways of producing electricity, we notice that solar panels are becoming increasingly popular, especially in Europe and North America but at present the cost of buying and fitting them to a roof is a deterrent to less wealthy home-owners. A set of panels can produce enough electricity to serve the needs of an average house but can cost as much as five times the normal cost of a year’s supply of electricity. When they become cheaper to install, they will make a greater contribution to energy conservation. However, ideally they need to be used on homes with a south-facing roof, but in large cities not all homes face south and can use solar panels.

In a number of countries, windmills are appearing in districts where the wind can be relied upon to power them for most of the time. The windmills may appear unsightly but they are a welcome source of electricity and are comparatively pollution-free. Some households already combine solar panels with their own small windmill so that they no longer have to rely on national electricity companies for their source of power. Indeed, some of them produce a surplus of electricity, which they sell to a national generator.

The movement of water in tidal estuaries and in the sea is being explored as a durable5 alternative method of obtaining electricity. In estuaries, barriers can be fitted to make use of the strong currents caused when the tide sends water racing up or down an estuary. In the sea, floating equipment moves up and down with the waves and—if current experiments succeed—will produce sufficient power for both coastal and inland cities.

In the past fifty or sixty years, the availability of cheap fuel (oil, gas, and electricity) has deterred scientists from searching for alternative methods of producing fuels. In this century, however, progress is being made in reducing our dependency on conventional sources. In Brazil, special crops are being grown so that their products can be crushed to produce a fuel for vehicles. Other experiments include boring down to reach geo-thermal sources, and there is even6 talk or trying to find a way of harnessing the amount of methane given off by grazing animals. If scientists can find a way of landing men safely on the moon, they can surely find methods of enabling us to survive when supplies of oil and gas give out. If they cannot, we will have to return to the days of a single (animal) oil lamp for each home.


1 What does ‘monitoring’ mean in this context? What must have puzzled those ‘creatures from another planet’?

2 What might cause the lights to become ‘dimmer’?

3 What reason is given in the second paragraph as contributing to the great rise in the price of fuel?

4 Where might we expect to see a hydroelectricity plant?

5 What decides whether a home needs an air-conditioner or central heating?

6 Explain the effect which industrialisation has had on the demand for fuel and the price of it.

7 Explain why the writer mentions horses and camels in the sixth paragraph.

1 Why is the need to conserve energy becoming more and more familiar?

2 What are the two problems that the writer associate with nuclear plants?

3 Why does the writer think that solar panels should be on a south-facing roof?

4 In what ways are windmills comparatively pollution-free?

5 Explain why getting electricity from the sea can be called a ‘durable’ method.

6 What does the writer imply by using ‘even’ in this context?

7 In a paragraph of about 160 words, summarise relevant information about the alternative resources of energy in this article.

Sample Answers

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