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("Greenhouse Effect" OR "Växthuseffekt") 1650+ documents
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What does (greenhouse Effect Or Växthuseffekt) mean? Let's check what the community at Wikipedia thinks
På svenska: Denna artikel behandlar endast växthuseffekten som fysikaliskt fenomen. Teorin om att senare tiders klimatförändringar till stor del beror på människans utsläpp av växthusgaser behandlas i artikeln global uppvärmning.Växthuseffekten (eller drivhuseffekten) är den uppvärmning av jordytan som åstadkoms av jordens atmosfär. Effekten beror på att en del av den värme som strålar ut från jordytan värmer upp luften i atmosfären i stället för att stråla ut i rymden. Jorden blir därigenom varmare än den skulle ha varit om den hade saknat atmosfär. I större eller mindre grad uppträder samma effekt också på andra planeter som är försedda med atmosfär. Lär dig mer på Wikipedia
In English: The greenhouse effect is a process that occurs after energy from a planet's host star goes through the planet's atmosphere and heats the planet's surface. When the planet radiates the heat back out as thermal infrared radiation, greenhouse gases in the atmosphere absorb some of it, heating Earth's lower atmosphere and surface. By trapping heat near the surface, they also cause the upper atmosphere to cool, reducing the amount of heat emitted into space and causing Earth to absorb more energy than it emits.Without the greenhouse effect, the Earth's average surface temperature would be about −18 °C (−0.4 °F) compared to Earth's 20th century average surface temperature of approximately 14 °C (60 °F). In addition to the naturally present greenhouse gases, human-caused increases in greenhouse gases are trapping greater amounts of heat. Burning fossil fuels has increased atmospheric carbon dioxide by about 50% over pre-industrial levels, which is the primary driver for global warming of about 1.2 °C (2.2 °F).Matter radiates energy at a wavelength related to its temperature. The Sun is about 5,500 °C (9,930 °F), so it emits most of its energy in near infrared and visible wavelengths (as sunlight). The Earth's surface temperatures are much lower, so it emits longer-wavelength thermal infrared radiation (radiated heat). Earth's atmosphere is made of gases that are transparent to visible wavelengths of light, allowing sunlight through to heat the surface. Most gases in the atmosphere are also transparent to thermal infrared wavelengths of radiation, but a small proportion of the atmosphere is made up of greenhouse gases that absorb them. After absorbing heat the greenhouse gas molecules re-emit it in all directions, warming other greenhouse gas molecules and the planet's surface. A runaway greenhouse effect occurs when greenhouse gases accumulate in the atmosphere through a positive feedback cycle to such an extent that they substantially block radiated heat from escaping into space, thus preventing the planet from cooling. A runaway greenhouse effect involving carbon dioxide and water vapor appears to have occurred on Venus. However, it is unlikely that human-caused greenhouse gas emissions alone could trigger a runaway effect on Earth. The term greenhouse effect comes from an analogy to greenhouses. Both greenhouses and the greenhouse effect work by retaining heat from sunlight, but the mechanisms differ. Greenhouses primarily retain heat by preventing the movement of air (blocking convection), although their panels also limit heat radiation and conduction. The greenhouse effect works only by reducing radiative heat loss to space. Learn more at Wikipedia
