English subtitles for clip: File:Erklärvideo zum "Treibhauseffekt".ogv

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The word greenhouse effect is so pictorial that it describes well what it means.

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It is getting warmer and warmer, like in a greenhouse, under a glass bell jar.

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The glass bell jar here would be the Earth's atmosphere.

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Our planet itself is getting warmer and warmer.

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There is only one detail that is wrong with this image.

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It is not the sun's rays that are responsible for the warming, as is the case with a greenhouse in the garden, but various gases in our atmosphere, the greenhouse gases.

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In detail, this is how it works.

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The sun shines on the Earth.

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Or, to put it scientifically, the sun radiates energy to the Earth in the form of electromagnetic waves.

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If we zoom in on this electromagnetic energy, we can see that it consists of futons, of wave particles.

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Is this important?

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The sun's futons are primarily short-wave.

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These short waves can penetrate our atmosphere without any problem.

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The solar energy therefore reaches the Earth's surface without any major detours and heats it up.

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The heated objects in turn also radiate electromagnetic waves, but

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The wave particles from the Earth's surface are much longer, almost twice as long.

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They are called infrared radiation.

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These long waves now travel from the heated Earth's surface back towards the atmosphere and this is where the greenhouse effect sets in.

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Two points are important for this.

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Firstly, the long waves of infrared radiation can no longer penetrate the Earth's atmosphere as easily as the short waves of the sun's rays could.

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The heat is therefore less able to be released into space.

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Secondly, in the atmosphere the infrared radiation hits the greenhouse gases.

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These are gases such as carbon dioxide, methane or chlorofluorocarbons.

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And these gases are infrared active.

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That means,

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They absorb the infrared waves, become warmer and then give off heat in all directions, including towards the ground.

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This is called atmospheric counter-radiation.

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What this means for our Earth:

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It not only receives the heat of the sun's rays, but also that of the atmospheric counter-radiation.

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And then it goes on like this.

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The Earth gives back infrared radiation and this is absorbed again and everything keeps getting warmer.

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Greenhouse effect.

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Greenhouse gases do occur naturally, but our industry and consumer behavior cause so many greenhouse gases to be artificially emitted that they have become a problem for the Earth and all life on it.

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You can't even say that we didn't know better at the beginning.

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The greenhouse effect was discovered by the French physicist Joseph Fourier, then known as the glasshouse effect.

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and was first described in more detail by the Swede Zvante Arrengius.