Yes, Eli's new favorite toy pinata, Peter L. Ward (As Hank points out below not to be confused with Peter D. Ward, an entirely reasonable fellow) just continues to amaze. Now some, not Eli to be sure, might consider Eli's behavior in this matter to be a tad evil, but there is good science to be learned fisking Ward apart. Why just in his next paragraph from the one Eli started with he continues to misunderstand pretty much all of thermodynamics and a whole bunch of other stuff.
The concept of flux as presently calculated is incorrect because it assumes that thermal energy is the same at every frequency.We observe that when ozone is depleted, more UV-B reaches Earth. We measure the changes in UV-B at earth’s surface. UV-B is the hottest solar radiation to reach Earth. If enough UV-B reached Earth, it could warm Earth to be 48 times hotter than Earth is. Luckily the amounts are low, the dosage is low. One can make the case that the mean surface temperature of Earth is directly proportional to the mean optical thickness of the ozone layer modified primarily by volcanic aerosols in the lower stratosphere that reflect/scatter solar radiation worldwide.Note the bolded phrase "thermal energy is the same at every frequency" because is it is a keeper.
To explain why, Eli would remind the bunnies that that the frequency distribution of light emitted from a body at a temperature T is described by the black body curve that our old friend Planck showed how to calculate and there are lots of apps like this one from PheT to show the spectrum
To understand where Peter Ward goes wrong, one only has to push or access the setup function on your monitor. There usually is a reference to something called color temperature (artists and art directors of ad agencies are very aware of this). What it means is that when white is displayed on the screen the spectrum matches the blackbody spectrum of emission from a, guess what, black body of that temperature. In general one should only discuss the temperature of radiation fields emitted from (near) black bodies.
Assigning a color temperature to solar radiation at the top of the atmosphere, makes a bunch of sense, it's about 5800 K. Assigning a temperature at the surface is a useful approximation (Rabett's First Law All approximations are wrong, some are useful. Rabett's Second Law: All surveys are really wrong, some are decent approximations). Talking about the thermal energy of anything requires that the anything has a measurable temperature. In the case of sunlight that is as Eli said, about 5800K (Bunnies can dial it in on the app). At 5800 K the amount of energy in the field of the electromagnetic radiation below 300 nm is about 3.6%. Notice that this does not require talking about photons with respect to the light but only classical electromagnetism.
So where is the good Peter L. Ward coming from when he says:
If enough UV-B reached Earth, it could warm Earth to be 48 times hotter than Earth is.(Eli hides his ears in shame for missing this. Rrrussel notes beow that 48 x 280K = 13,440K a reasonable temperature for the interior of a white dwarf star)
To see why one should start with a description of a black body in physics speak. Black bodies are collections of oscillators which can jiggle at any frequency. When the oscillator jiggles it can emit electromagnetic radiation at the frequency it jiggles at. If that were the only issue, then Ward would be a lot closer to reality, but it is not. Before Planck this was how physicists tried to calculate the black body curve by assuming the oscillator could emit any amount of energy at the jiggle frequency.. When Rayleigh and Jeans tried it they found the "ultraviolet catastrophe", where the amount of thermal energy in the UV went to infinity in the calculation (but of course not in reality). However, the probability of exciting a high frequency (e.g. high energy) jiggle is not the same as exciting a low frequency one. This is what Planck showed, that the probability of exciting an oscillator with frequency ν is (exp[hν/kBT]-1)-1 and thus the average energy of an oscillator at frequency ν is just
where the energy of the oscillator is hν. The probability of exciting a high frequency oscillation goes rapidly to zero, limiting the amount of energy in the UV emitted by the Sun (to 3.6% of the total energy in the radiation field below 300 nm). When exchanging with Peter Ward, Eli would strongly recommend reminding him about how the black body radiation curve is calculated (and how the calculation matches measurements).
So the bunnies see that Peter L. Ward needs a course in thermodynamics, but perhaps not, given the dangers of thermal science. Carnot, died at 36 in an insane asylum, Benjamin Thompson, Count Rumford, was attacked by a mob and driven into exile, Ludwig Boltzmann committed suicide as did Paul Ehrenfest. Ignorance of thermal science may be a good thing.
Eli, . . . . . Eli is an old bunny.