“I have largely retired from RealClimate due to the fact that people here would rather talk to chatbot et al. than to me, as they find AI more ‘friendly’ than somebody who actually talked with my father. every morning for years, because they found my sharing or real conversations incoherent. fwiw, that is a good illustration of what’s wrong with AI, aside from its extreme environmental costs and inhumane coercions.”

It is not a problem with AI, it is a problem with an increasing number of dysfunctional people in society. AI is not a substitute for human connection but it is great as a learning and advisory tool. It doesn’t mock, it doesn’t judge, it doesn’t make nasty cynical assumptions about your questions, it doesn’t try to bully you into silence if you question it, it doesn’t pander to toxic populism, it doesn’t have ego, it doesn’t have a tribe or identity to protect, it gives solid, grounded answers to questions on subjects like astrophysics, climatology, human psychology, relationships, systems, game analysis, coding problems and much more where a suitable human is unavailable. AI has the benefit of being able to draw on a huge database of information, a human is largely restricted to their own experiences and world view. Introduce me to a climate scientist in my town that would be happy to have a discussion with me about anthropogenic climate change along with potential consequences and communication of those risks, and I will happily go out for a drink with them.

in Re to MA Rodger, 25 Jun 2026 at 4:19 AM,

https://www.realclimate.org/index.php/archives/2026/06/unforced-variations-june-2026/#comment-849404

Dear MA,

Thank you very much for your remarks.

I think that what Barry criticizes may be, basically, superficial handling with relatively complicated concept of heat transport in Earth atmosphere generally and with the role of the downwelling infrared radiation therein specifically. I admit that I often do not understand what his comments mean, however, I guess that in the present case, his core objection might have been relatively clearly expressed in his contribution of 23 Jun 2026 at 4:51 AM,

https://www.realclimate.org/index.php/archives/2026/06/unforced-variations-june-2026/#comment-849357 ,

Herein, he objects that the downwelling radiation results from ALL kinds of energy absorbed and thermalized in the atmosphere, including e.g. non-radiative heating mechanisms like water vapour condensation, in accordance with energy flow balances demonstrated in Trenberth’s diagrams.

I think that this fact, along with the circumstance that the emitted infrared radiation is almost exclusively generated by thermal activation of the respective IR-active vibrational energy transitions by collisions with other air molecules (in other words, not directly by absorption of another electromagnetic radiation as it seems to be supposed e.g. by Ray Ladbury) may be the key reasons why Barry considers the terms like “back radiation”, “re-radiate”, “re-emit” etc. as potentially confusing and thus inappropriate.

As I noted, I am not completely sure if I grasped the thoughts presented by Barry and Ray correctly, however, I hope that this attempt to summarize the previous discussion might at least serve as a basis for final clarification by them.

Best regards
Tomáš

A sort of back of the envelope kind of reasoning can explain the phenomena without resorting to detailed analysis. I’m not dissing detailed analysis, it’s necessary to obtain a correct quantitative prediction. In any case the stratosphere can be thought of as being optically thin. Any photons emitted in the upward direction can be assumed to escape to space. Heating is a combination of the absorption of upwelling infrared, and the absorption of solar UV. The later is not effected by CO2 concentration. So an approximately unchanging amount of energy to be radiated by the stratosphere has more local CO2 molecules to do the emissions. That leads to a lower local temperature.

correction, Plass offered not a different mechanism than Callendar, just calculated with more precision using high speed electronic computer. Same conceptual error.
This copy has comments/annotations by Pierrehumbert: https://geosci.uchicago.edu/~archer/warming_papers/plass.1956.radiation.pdf

Martin

No. Energy can be transferred from the atmosphere to solid matter by direct contact. (I’m not clear on what you mean by “the” energy.)

And, as I pointed out to Ray, “up and down”, and “inbound and outbound” are not generally valid descriptors for an emitted photon.

I think it is quite possible to correctly describe what is happening with a minimum of jargon, but you have to work at it. And it is obvious that when people keep adding more details and terminology, it mostly causes more confusion.

The problem with the UK is that by the time you have adapted to it, the heatwave ends and it is back to low-mid 20’s. I have managed better than anticipated by aiming my fan out of the bedroom window and opening windows on opposite sides of the house. This has worked reasonably well or as best as I can do, last night I managed to get the house from 29C to 26C even though it was still around 24C at midnight, still uncomfortable but with the fan on low blowing air across me and around the room, I could sleep. Today is the last >30C day before a fairly rapid cool-down over the weekend, my house will soon shed its accumulated heat.

European heatwave is worst ever and impossible without climate crisis, scientists say:

https://uk.yahoo.com/news/european-heatwave-worst-ever-impossible-040009080.html

Tom Harris offers a good current snapshot compilation for those new to the topic. Nothing that wasn’t known about 25 years ago, only it’s no longer hypothetical or located in the distant future. A most depressing state of affairs. And likely a waste of time to even write it up for all the good it will do. Reminds me of reviewing the FAR through to AR7 , every COP since Rio and every book ever written on Climate Change. A waste of time and effort while fortunes were made and lost.

Say for concept illustration only (not accurate) that 200 w/m**2 leaks out the top and that is emitted by molecules over an altitude range of 4 to 12 km with an effective average of 7 km.

Say for concept illustration that 345 w/m**2 leaks out the bottom and that is emitted by molecules over an altitude range of 0.0001 to 1.5 km with an effective average of 1 km.

Suppose a certain amount of CO2 was added into troposphere and mixed then instantly the upper & lower ranges would need to be closer to their respective ends because more CO2 molecules in the way.

The effective averages of 7 km for upwelling into or through stratosphere and 1 km for downwelling into surface change to 7.05 km and 980m respectively, with the upwelling & downwelling Power fluxes consequently changing to 199 w/m**2 and 346 w/m**2 respectively due to being produced by higher-than-before (colder) and lower-than-before (warmer) air parcels.

There has been no change in the 545 w/m**2 leaving the troposphere, there is no “magical extra energy”, the surface downwelling radiation has increased 1 w/m**2, an additional ~480 terawatts heating the ocean and Earth is emitting less radiation to Outer Space (a Power reduction of 510 terawatts).