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Have you ever heard about the greenhouse effect? It work.4 like this; sunlight gives us heat. Some of the heat warms the atmosphere, and some of the heat back into apace. Nowadays the air surrounding the earth has become much warmer because the heat can’t go back into space. That's why winter and summer temperatures in many places have become higher.

During the last 100 years people have produced a lot of carbon dioxide. This in the atmosphere works like glass in a greenhouse. It lets heat get in, but it doesn't let much heat get out. So the atmosphere becomes warmer. Where does the carbon dioxide come from? People and animals breathe in oxygen, and breathe out carbon dioxide. We produce carbon dioxide when we burn things. Trees lake this gas from the air, and produce oxygen. But in the last few years, people have cut and burnt big of rainforest. This means there are fewer and, of course, more carbon dioxide!

As we see the climate in different parts of the world changes a little from year to year. These changes can be dangerous for our fragile planet which needs protection. Earth is millions of years old, much older than the humans. We know many of its secrets. Yet there is still much to learn.

1. a) Work in pairs. Analise the list of the environmental problems

and speak what you’ve already known about them.

The planet Earth is only a tiny part of the Universe, but it's the only place where human beings can live. People always polluted their surroundings. But until now pollution was not such a serious problem. People lived in uncrowded rural areas and did not have pollution caused by machines. With the development of crowded industrial cities, which created huge amounts of pollutants, the problem has become more important. Today our planet is in serious danger. Acid rains, climate change, air, land and water pollution, deforestation, endangered species, and overpopulation are the problems that threaten human life on Earth.

Something is happening to our climate. It is getting warmer. Our springs and summers are very hot, and there isn't much snow in winter. Most scientists say that people are responsible for these changes. Our forests are disappearing because they are cut down or burnt. If this trend continues, one day we won't have enough oxygen to breathe.

The rivers and seas are in danger. They are filled with poison: industrial and nuclear wastes, chemical fertilizers, and pesticides. If nothing is done about it, one day nothing will be able to live in the seas. Air pollution is another serious problem. Cars and factories emit tons of harmful chemicals. These emissions have awful consequences for our planet. They are the main reason for the greenhouse effect and acid rains. And on land, there is garbage everywhere. It is ugly to see this, and it is dangerous for people and animals.

Every ten minutes, one kind of animal, plant, or insect dies out forever. If nothing is done about it, one million species that are alive today may soon become extinct.

The world population is growing. Every day, 200,000 people are born on our planet. In the future, there will be many more people, and they will need more food, water, houses, and energy. And an even greater threat is posed by nuclear power stations. We all know how tragic the consequences of the Chernobyl disaster are.