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| Lead In |
1. Work in teams. Brainstorm all the words and phrases you know related to the word environment. Present your mind map to the rest of the class and explain how the ideas are connected.
2. Work in small groups. Which of the environmental problems listed below are the most serious? Put them in order, 1-7 (1 = the most serious, 7 = the least serious). Give reasons for your choice.
§ global warming/climate change
§ air/water/soil pollution
§ shrinking habitats and loss of bio-diversity
§ acid rain
§ ozone layer depletion
§ deforestation
§ natural disasters: floods, heavy rainfalls, violent storms, droughts, etc.
3. Match the environmental problems with the factors that cause them. Some factors may go with more than one problem. Choose to write about three problems and their factors.
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Functional language: Cause and effect
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| Reading |
1. Look at the definition. Which environmental problem does it refer to?
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2. Look at the picture below. With a partner brainstorm your ideas about acid rain. What causes acid rain? How can it harm the environment?
3. Look through the text about the acid rain problem and check your predictions.
Acid rain is strongly acidic rain that absorbs microscopic particles of nitric
acid or sulfuric acid as it falls towards the ground. But why do we have acid
| Study help The meaning of a word or expression can often be worked out from the rest of the context of the sentence, e.g. “sulfur and nitrogen oxides are released into the atmosphere.”From the context, to release must mean something like to throw out or emit. |
rain? The reason lies in atmospheric pollution. As human beings developed their economic behavior, they began to use huge amounts of fossil fuels such as coal and oil. When fossil fuel is burned, sulfur and nitrogen oxides are released into the atmosphere. These pollutants are affected by ultraviolet rays and combine with atmospheric water vapor to form tiny particles of nitric acid and sulfuric acid that float in the atmosphere. When these particles dissolve into rain, it falls to the ground as acid rain. This process is called "wet deposition". At other times these pollutants are absorbed into fog or mist in a gas or particle form, are deposited on
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forests, and eventually return to the soil; this is called "dry deposition."
Chemical substances released from chemical plant chimneys are a major factor in the contamination of the atmosphere and lead to the formation of acid rain.
Many of us have our own “private factories” for producing modern acid rain - cars. Vehicle exhausts contain NOx (nitrogen oxides), hydrocarbons and other chemicals.
The damage caused by acid rain first appears in rivers, lakes and marshes. When the water of a lake or marsh declines to pH5 or so, at first the plankton and aquatic vegetation disappear. Needless to say, the fish that feed on these living things also decline in number and even die out.
Then, as the acidity level of soil increases, aluminum and other harmful metals contained in the soil begin to dissolve, which also contributes to the death of aquatic life. Eventually the lakes cannot support life at all.
Acid rain makes soil highly acidic, which leads to the drying and death of forests. Soil naturally contains many metallic ions such as calcium and magnesium, and these help to neutralize acid to a certain extent, even in the case of acid rain. However, when this neutralization power is exhausted, the acidity of the soil increases, killing microorganisms and worms. There are also cases when acid rain enters directly into the leaves, trunks, and branches of plants and damages trees.
The damage created by acid rain in Europe and North America is truly grave. It is reported that in many European countries about one half of the total area of forests has been damaged.
Countries like Sweden, Norway, and other Scandinavian countries do not contribute much to atmospheric pollution, but they are suffering extensive damage from atmospheric pollutants carried there from other countries. For example, it has been reported that fish have disappeared from one-third of the lakes and marshes of Norway.
In Asia, acid rain is having truly serious consequences in China, which is the second largest producer of coal in the world. Furthermore, with the expansion of industry and the spread of the automobile, acid rain is becoming a serious issue even in developing countries.
Historical sites and buildings are also damaged by acid rain, especially in Europe with its many historical buildings made of marble and copper. The chemical reaction between marble and sulfuric acid changes the marble into plaster. Therefore, ancient sculptural works made of marble often crumble after contact with acid rain. Copper items also break down in contact with acid rain. For example, the copper plates of the United States' Statue of Liberty were eaten away to a dangerous degree by acid rain, and needed large-scale reconstruction. Historical structures and buildings, which have been handed down as cultural heritage for centuries, have been in danger of being lost in the past several decades simply because of acid rain.
Acid rain is no longer someone else’s problem: it’s happening here.
(Adapted from http://www.virtualglobe.org/en/info/env/)
4. Read the text again and complete the cause and result chart for acid rain.
| ACID RAIN |
| What causes it? What are the consequences? |
| exhaust gases from cars increase the amount of dangerous gases in the atmosphere |
| …………………… kill(s) fish |
| …………………… pollutes the soil |
| …………………… ………………….. |
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