4) The green house effect
Even though the temperature at the surface of the Earth is +15 [°C] (59°F), when observed from space the temperature of the planet is -19 [°C] (- 2.2°F).
The fact that the surface temperature of the Earth remains +15 [°C] (59°F) is of course due to the solar rays that are not immediately reflected towards space or immediately absorbed by the atmosphere.
A large part of these rays therefore go through the atmosphere and reach the ground. In return, the heated ground sends infrared rays towards the atmosphere.
These infrared rays coming from the ground are partially captured by the atmosphere, which allows the planet to maintain its temperature around +15 [°C] (59°F) close to the ground, while its temperature around 5,000 [m] altitude is -19 [°C] (- 2.2°F).
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