A planet does not emit at a SINGLE temperature
It was very much mistakenly asserted:
"If you take the average temperature of the earth, you can find the resulting blackbody spectrum."
Link to the image:
We have already demonstrated in the HOME PAGE and elswhere in this site that two planets with the same mean surface temperature (Tmean) may emit dramatically different amounts of INFRARED radiative energy.
Please see the Moon-Mars comparison data, also see the planet Jupiter's satellites Io - Ganymede Tmean (110K & 110K).
Therefore, the planet average surface temperature (Tmean) cannot reffer to any kind of the planet average surface the INFRARED radiative energy spectrum!
I would like to focus here on the issue of the Infrared Spectrum Of The Earth.
A planet emits infrared radiation, when in a radiative energy equilibrium, a planet emits on a constant rate of
Energy out = Energy in
Also a planet has its average surface temperature (Tmean), for Earth it is estimated as Tmean.earth =288K
A planet does not emit at its average surface temperature (Tmean).
Therefore, a planet's average surface temperature (Tmean) cannot be associated with any kind of planet surface Infrared Emission Spectrum!
A planet does not emit at a single temperature
Jemit = σT⁴ W/m²
Earth does not emit
σ(Τmean.earth)⁴= σ*(288)⁴ W/m²
Consequently, the satellite measured infrared (frequency-by-frequency) for some local place the measured infrared emission curve cannot be compared with the planet average surface temperature the alleged (blackbody) emission curve, because there is not any such emission curve, since planet does not emit at its average surface temperature.
They have confused the emission curves comparison with the emission comparison in the case of stars.
They neglect a very important difference stars and planets have!
Stars have a uniform surface temperature, whereas planets have average surface temperature...
And stars have their own inner infinite source of energy, when planets emit the radiative energy falling and interacting upon their surface.
Below we demonstrate (some two of the many paradigms in internet) of the unfortunate earth's infrared emission curves comparisons with the earth's alleged blackbody 288K infrared emission curve.
In those unfortunate comparisons the gaps (the missing radiative energy) is attributed to the greenhouse gases radiative energy absorption bands.
What we notice here is that there is not any such absorption take place, because we are not justified to compare those curves!
Actually, there is not any measured emission from earth's surface on those frequencies which is then being absorbed...
Atmospheric gases cannot absorb, what is not emitted by the Earth's surface!
"The Infrared Spectrum Of The Earth
Last Updated on Sun, 11 Dec 2022| Origin of Life
Figure 13.4 shows the infrared emission spectrum of the Earth, as seen from space. This is not the spectrum obtained by the Galileo spacecraft but a much more detailed one obtained by the Nimbus-4 satellite in the 1970s. This particular spectrum was acquired in daytime above the western Pacific Ocean, and has been chosen because it resembles the sort of spectrum that would be obtained from a cloud-free Earth from a great distance, when the light from the whole planet would enter the spectrometer. The vertical scale shows the power emitted from the Earth at each wavelength (note that the wavelength scale is logarithmic - see Section 11.2).
There are several smooth curves, each labelled with a temperature. These correspond to emission from a surface that is black at infrared wavelengths, and has temperatures equal to those shown. There is also a jagged curve displaying much detail. This is the infrared power emitted by the Earth. It is the detail in frequency in millions of megahertz frequency in millions of megahertz wavelength in micrometers."