Understanding Earth's Energy Balance and Greenhouse Effect

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[...] The Earth absorbs 240 W/m² of solar radiation on average (340*0.7). To avoid melting, the Earth has a way to evacuate heat back, and it's also through radiation. The Earth also emits electromagnetic radiation into space at all times, and just like the Sun, this radiation has a certain spectrum. N is according to temperature Suppose the Earth without a greenhouse effect. To reach equilibrium, it must also radiate 240 W/m², which is the area under the Planck spectrum curve that we would have for a surface temperature of -18°C. [...]

[...] Is the greenhouse effect saturated? - Grand oral Introduction A common climate-sceptic argument is that the greenhouse effect would be saturated. That the greenhouse effect would already be at its maximum. But is the greenhouse effect really saturated? The argument is incorrect, and we will see why. I. Development 1 The Sun provides the Earth with the vast majority of its energy through radiation. The Sun emits its light within a certain range of wavelengths. Let's plot the curve showing the intensity of the emitted radiation as a function of wavelength. [...]

[...] We therefore have an enclosure of the integral. To be more precise, let's increase the number of rectangles. We arrive at a more accurate enclosure as we multiply the rectangles. This is still not very satisfactory. Primitive Method Let's apply the primitive method. Let f be a continuous function on the interval b]. We call a primitive of the function on a function F that is differentiable on and whose derivative is equal to f. For all x in the interval, = f(x). [...]

[...] They absorb certain bands of infrared, and radiate following Planck's law. Let's reason by successive layers : This does not last indefinitely, since the air becomes thinner as you go up in altitude, there are fewer and fewer CO< sub >2 molecules.2, less and less absorption and more and more transmission, until the radiation completely escapes into space. In the hole of the spectrum, the photons that reach space come from higher altitudes located at 10 and 20 km, where it is 217 K (about -60°C). [...]

[...] To understand, let's look at the absorption bands of CO< sub >2.2. Its main absorption band is at 15 microns. We can wonder what fraction of this radiation is currently absorbed by CO< sub >2.2 of the atmosphere. And the entire thing. We could therefore triple the concentration of CO< sub >2.2, This would not change anything because it already absorbs everything. The impact of CO< sub >22 on the greenhouse effect would already be saturated. [...]