About Greenhouse Effect
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- The greenhouse effect is a naturally occurring phenomenon that blankets the earth lower atmosphere and warms it, maintaining the temperature suitable for living things to survive.
- Water vapour and greenhouse gases warms the Earth.
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(i) Incoming Energy
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- The Sun emits energy that is transmitted to Earth.
- Because the Sun is very hot, the energy is emitted in high-energy short wavelengths that penetrate the Earth’s atmosphere.
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(ii) Absorption
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- About 30% of the Sun’s energy is reflected directly back into space by the atmosphere, clouds, and surface of the Earth. The rest oi the Sun’s energy is absorbed into the Earth’s system (70%)
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(iii) Emission
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- The Earth re-emits energy back into the atmosphere. Because the Earth is cooler than the Sun, the energy is emitted in the form of infrared radiation, at wavelengths longer than the incoming solar energy.
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(iv) Role of Greenhouse Gases
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- Greenhouse gases in the atmosphere absorb much of the long-wave energy (infrared radiation) emitted from the Earth’s surface, The greenhouse gases then re-emit this energy in all directions, warming the Earth’s surface and lower atmosphere.
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