Global Warming and the Greenhouse Effect

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What is the "greenhouse effect?" It is the behavior of solar radiation when it interacts with gasses in the Earth's atmosphere. The Sun gives off a wide spectrum of energy which we classify according to its wavelength. Among the types of energy given off by the sun are ultraviolet (UV), visible and infrared (IR) wavelengths. UV is short wavelength high-energy radiation, visible is mid-wavelength, mid-energy radiation, and IR is long wavelength low-energy radiation. The atmosphere is mostly transparent to UV and visible light, but some components of the atmosphere absorb IR energy on its way in toward the Earth's surface, warming the atmopsphere slightly. When the sun's energy reaches the surface of the Earth it is absorbed. This warms the surface, and causes the Earth to emit energy of its own. Unlike the Sun, however, the Earth does not emit UV or visible light, it ONLY emits IR energy. As this IR radiation travels back toward space it is also absorbed by gasses in the atmosphere, particularly CO2, methane and water vapor. In this way the Earth's atmosphere acts like the glass in a greenhouse. The greenhouse lets in the UV and visible light, but once the interior warms up and IR energy is re-emitted, the glass absorbs the radiation and does not allow it to escape back to space. This warms the greenhouse. The fact that all incoming wavelengths are absorbed by the Earth and re-emitted as IR is the key to the greenhouse effect, both on the Earth, and in the greenhouse. The "greenhouse effect" is important to the Earth because it keeps the planet at a nice, warm, habitable temperature. However, many scientists, policy makers and c... ... middle of paper ... ... The devastating floods, droughts and storms we have seen in the UK and across the world in recent years show all too clearly how vulnerable we are to climate extremes and how high the economic, human and environmental cost can be, particularly in developing countries. The greenhouse effect causes trouble by raising the temperature of the planet. The actual rise is not very much, but the Earth's ecosystem is very fragile, and small changes can have large effects Inter-Governmental Panel on Climate Change has predicted that this rise of one degree will happen by the year 2025 The other serious worry is that rising sea levels from the melting of the polar ice caps could severely flood many countries. A rise in sea levels of one metre, which many experts are predicting by the year 2100 (and some as soon as 2030),
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