I took the radiate transfer model used by NCAR (RRTM) and ran it with tropical humidity (0.025 mole fraction H2O) and three levels of CO2. Results are shown below.
- 0 ppm 392.3 w/m²
- 364 ppm 397.5 w/m²
- 3640 ppm 403.8 w/m²
CO2 contributes almost nothing to the greenhouse effect in the tropics. The removal of all CO2 would only lower downwelling longwave radiation by 1.3%. A 10X increase in the amount of CO2 would only increase downwelling longwave radiation by a little over 1%.
At lower surface humidity (0.015 mole fraction H2O), co2 contributes about 2.5% of the greenhouse effect.
- 0 ppm 372.8 w/m²
- 364 ppm 381.3 w/m²
The role of CO2 is wildly exaggerated by alarmists. Gavin typically uses a number somewhere around 30%, when in fact the real number is less than 5% over most of the Earth’s surface.
“The removal of all CO2 would only lower downwelling longwave radiation by 1.3%.”
Yes, but you are forgetting the upwelling, sidewelling, catty-cornered welling, circular welling, insideout and outside inwelling, and countless self inflating feedbacks…
I think the model calculates all the static effects. Hansen’s imaginary feedbacks are not included.
CO2 doesn’t do squat. If we loaded the atmosphere with 40,000 parts per million CO2, it still wouldn’t do squat as far as climate. Look at Venus, it has nearly 100% CO2, and CO2 has nothing to do with why it’s hot on that planet. 40,000ppm would still be just 4% CO2, and at the current ~ 380ppm we have now just .038% CO2, talk about ultra-trace.
There’s nothing wrong with the climate, and CO2 has nothing to do with it.
Me and my green friends demand 1200 ppm.
Did you calibrate your model to a pre-selected set of bristlecone pines? No? Well that is the proper climate scientist method. Hansen’s sensitivity comes from dendro records, and we all know how honest and accurate the folks that put those together are.
Excellent work sir!
They lie. They are corrupt UN flunkies.
Water vapour feedback is required to amplify the warming effects of CO2. CO2 by itself is likely a net benefit to the plant not a negative. (1.1-1.3C of estimated warming for a doubling.) However, most of the atmospheric water vapour content is going to be found in the tropics…