What is air?
Air is a mixture of different gases that covers the Earth in a layer over 400 miles high. This layer is called the atmosphere. It contains roughly 78% nitrogen, 21% oxygen, and smaller amounts of argon, hydrogen, carbon dioxide, and others.
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Why is air so important?
Air is needed by almost all the living things living on Earth. Most plants and animals take in air, use the oxygen in it and give out another gas, carbon dioxide. This process is called respiration. Air also protects life on Earth by absorbing harmful ultraviolet solar radiation and reducing temperature extremes between day and night.
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What are greenhouse gases?
Gases such as carbon dioxide, water vapour and methane that allow incoming sunlight to pass through but absorb heat radiated back from the Earth's surface are called greenhouse gases. If the atmosphere contains more of these gases, it traps more heat and warms up. This is known as global warming.
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What is air pollution?
Air pollution is the contamination of air by the discharge of harmful substances. One type of air pollution is the release of particles into the air from burning fuel for energy. Natural phenomena such as the eruption of a volcano also causes air pollution.
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Why is air pollution such a serious problem?
Air pollution can cause many health problems such as burning eyes, cancer, birth defects, brain damage, or even death. Air pollution can also damage the environment and property such as trees, lakes and buildings.
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How can we reduce air pollution?
There are many ways to reduce air pollution. A simple way is by using less electricity. Another way to reduce air pollution is to make fewer journeys by car. Walk, cycle or use public transport whenever possible.
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External links
Environmental Protection Agency
Earth Science Enterprise
Wikipedia
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