НАУЧНАЯ БИБЛИОТЕКА - РЕФЕРАТЫ - The enviromental problems which concern the Mankind - (реферат)
The enviromental problems which concern the Mankind - (реферат)
Дата добавления: март 2006г.
The environmental problems which concern the Mankind.
I’m going to speak about some kinds of pollution, for example air pollution or acid rain, water pollution. Now different kinds of trees, many of the animals, birds, fish are in serious danger. What should government do to stop the polluting, nowadays?
First of all I would like to speak about water pollution There is no ocean or sea which is not used as a dump. Many rivers and lakes are poisoned, too. Fish and reptiles can’t live in them. There is not enough oxygen in the water. It happens so because factories and plants produce a lot of waste and pour it into rivers. In the 1970s, many of the elm trees in Europe were killed by Dutch elm disease. Now an even greater danger is threatening the woods and forests of Europe. This new danger attacks all trees–deciduous trees like oak, beech, birch as well as coniferous trees like fir and pine. First the branches turn yellow and brown. Then the tree’s needles or leaves fall. The roots and the trunk shrink. Finally the tree die. But what is killing the trees. Nobody knows exactly but it is probably air pollution or acid rain. Factories, power stations, cars emit tons of smoke into the air. This smoke contains sulfur dioxide and nitrogen oxide. These substances mix with water vapour in the atmosphere and form sulfuric acid and nitric acid. Sunlight turns these acids into the poisonous oxidants which fall in rain or snow onto the trees. Unfortunately acid rain doesn’t always fall on the countries which produce the pollution. The wind carries the poisonous substances from one country to another. In some parts of the world trees are threatened by people. The great rain forests of Asia or South America are being destroyed for firewood and building material. Trees are important because they provide home for many other plants and animals. They provide food for insects, reptiles, birds and mammals. They protect the soil from the wind and rain. It may be that the medicines we need will be discovered in wild plants in savannas, deserts or rainforests. Most important of all Trees are the lungs of the planet. If the trees die, we will too. Animals and birds are in danger too. Many of the animals are now extinct. The reason is a Man that killed animals and destroys their habitats. We used a lot of electricity. Our house is full of electrical appliances. Using electricity doesn’t cause the pollution, but making it does. There are many way to make electricity. For example, Nuclear Power Stations, HydroElectric Power Stations, Fossil Fuel Power Stations and some alternative means of energy like windmills and solar mirrors. They all have there advantages and disadvantages. Nuclear Power Station doesn’t cause any pollution and it is very effective, but It has to be build and looked after very well, the used fuel needs to be stored very carefully and it still give out the radiation. Hydroelectric Power Station also doesn’t cause any pollution and there is no fuel to pay for. But dams can cause flooding, it is expensive to build because it should be build up to very high standards. Fossil Fuel Power Station is cheap and the world has large stocks of fuel. It causes acid rain and a global warming effect. Alternative means of energy don’t cause any pollution, they are cheap and there is no fuel to pay for. But now they are not effective enough and are very noisy. To produce much electricity you need to build a lot of them– it’s expensive. We need to choose cheap electricity and polluting the environment and expensive electricity but healthy life and clean environment. But what government can do with it? I think government can stop producing nuclear and chimic weapon, allocate more money to various environmental projects, use organic fertilizer, install purifying systems, plant and grow trees bushes and other greenery. Mass media should atrach people’s attention to environmental problems. Everything I have already spoken about it is only a small part of nowadays polluting the environment. Everyone should remembers when he kills a plant or animal he kills a part of himself because everything in the world is interconnected. And people should to protect the nature but not to kill it.