“Slight warming of the air is also observed with [100,000 ppm] CO2 but is close to the temperature resolution of the sensors with ±0.1°C. Given an approximately 400 times lower CO2 concentration in the atmosphere, this warming is likely negligible.” – Schnell and Harde, 2026
New lab experiment research shows that the addition of 100,000 ppm (10%) CO2 – a volume orders of magnitude greater than today’s 425 ppm (0.0425%) – leads to a temperature change of about 1.0°C.
(Interestingly, the experiment shows this magnitude of temperature change can also be accomplished by adding argon (Ar), a non-greenhouse gas, and hydrocarbon gas (HCG), a propane/isobutane mixture.)
“With an initial temperature of the earth plate of +30°C, a temperature increase of 1.0°C can be observed after adding [100,000 ppm] CO2.”
But this CO2-induced (or Ar or HCG) temperature change (~1.0°C) is accomplished when assessing only radiation heat transfer effects and excluding the effects of convection. In the real world, heat is not transferred solely via radiation. In fact, convection, not radiation, dominates the heat transfer process here at the surface and throughout the lower troposphere.
So when convection is included as a contributing factor in these lab experiments (see also Wagoner et al., 2010 or Seim and Olsen, 2020), the temperature effect of adding 10% CO2 is reduced to just 0.1°C. This temperature change is so negligible that it is effectively below the resolution of the measurement sensors.
The real-world atmosphere has convective heat transfer dominating and 100s of times smaller CO2 concentrations than in this lab experiment. Thus, it can be concluded that the climate sensitivity to even a massive CO2 increase is effectively zero.
“HCG [hydrocarbon gas] causes a cooling of 2.5°C without convection, compared to only 1.3°C with convection; CO2 [100,000 ppm] leads to a cooling of 0.8°C compared to 0.1°C with convection. This shows that convection is a dominant heat transport mechanism that reduces the radiative effect.”
“When convection is allowed, greenhouse gases only slightly reduce the radiation reflected from the dome to the warm plate, causing a slight cooling, and correspondingly, only a slight decrease in the radiation emitted to space.”
This post was truly worthwhile to read. I wanted to say thank you for the key points you have pointed out as they are enlightening.
[…] No Tricks Zone: Experimental Lab Research: The Climate Sensitivity To A 400-Fold Increase In CO2 Is 0.1°C […]
Lab spectroscopy: doubling of CO2 causes +1.0 to +1.2° C warming.
Temperature increase represents the “no-feedback” climate sensitivity. It is a foundational, mathematically proven value derived strictly from laboratory spectroscopy and the laws of physics. Established by physicist Gilbert Plass in a series of landmark papers published in 1956, most notably “The Carbon Dioxide Theory of Climatic Change. This measurement has never been refuted
Plass work is known to be wrong since 1969, thanks to Kondratiev reference book “Radiation in the atmosphere” :
It is shown in this book that when heat equilibrium including evaporation/condensation and convection is taken to account (and not merely the radiative equilibrium which doesn’t exist in the actual atmosphere), CO2 effect is to slightly cool the atmosphere.
The only aera where it could warm is at the tropical tropopause : but observations never showed a warming of this zone.
Since then, no actual observation has shown that CO2 warms anything and data analysis shows no correlation from from CO2 concentration towards global temperatures. Instead, it shows a weak negative correlation.
“CO2 effect is to slightly cool the atmosphere”
100% of scientists disagree with you and claim that CO2 causes warming in the troposphere
Petit-Barde: “CO2 effect is to slightly cool the atmosphere”
Richard Greene: “100% of scientists disagree with you”
Scientists:
Wang and Tang, 2022
https://iopscience.iop.org/article/10.3847/PSJ/ac6d65
“In this study, we examine the driving mechanism for the atmospheric overturning circulation on dry, tidally locked rocky planets without the condensation of water vapor or other species. We find that the main driving process is the radiative cooling of CO2 (or other noncondensable greenhouse gases) rather than CO2 greenhouse warming or stellar radiation. Stellar radiation is the ultimate mechanism but not the direct mechanism. Due to the combination of the uneven distribution in the stellar radiation and effective horizontal energy transports in the free troposphere, there is strong temperature inversion in the area away from the substellar region. This inversion makes CO2 have a radiative cooling effect rather than a radiative warming effect for the atmosphere, the same as that in the stratosphere of Earth’s atmosphere.”
“The existence of CO2 makes the surface warmer (greenhouse effect) and meanwhile the atmosphere colder (radiative cooling effect)”
“adding CO2 obviously cools the whole free atmosphere“
And totally ignores the effects of atmospheric air movement.
These two physicists have just proven Plass wrong. !
From the math and physics of compressible flow, we know that the radiative influence of incremental CO2 on the climate system is negligible.
Vanishingly weak.
Not discoverable directly by any means we have available to us.
Not capable of driving “warming” or ANY trend of ANY climate variable.
Interesting perspective. It’s always valuable to see experimental work added to the discussion, even when it challenges prevailing views. Thanks for sharing the research.
[…] Experimental Lab Research: The Climate Sensitivity To A 400-Fold Increase In CO2 Is 0.1°C […]
[…] From NoTrickZone […]
A 10% increase in Carbon Dioxide implies a corresponding decrease in the other gasses. Do we then have 10% less Nitrogen and 10% less Oxygen? That leaves Oxy at 18.9. Combustion would be less likely but not impossible. Air breathers would lose consciousness and die.
There are 20+ things that affect the climate. CO2 is not one of them.