The mainstream science says. “Without any feedbacks, a doubling of CO2 (which amounts to a forcing of 3.7 W/m2) would result in 1°C global warming, which is easy to calculate and is undisputed. https://en.wikipedia.org/wiki/Climate_sensitivity#Sensitivity_to_carbon_dioxide_forcing
Only 1°C for a doubling of CO2. And to get a further increase of 1°C CO2 would have to be doubled yet again from this new level, & this means twice as much CO2 will be needed as the previous doubling for only the same result,,, 1°C. It gets doubly harder to warm the atmosphere using CO2 every doubling. Nothing to be alarmed about.
300ppm to 600ppm = 300ppm increase = 1°C
600ppm to 1200ppm = 600ppm increase = 1°C
1200ppm to 2400ppm =1200ppm increase = 1°C
Next
The mainstream science says that greenhouse forcing, unlike any other forcing, must warm the upper troposphere faster than the surface. This is referred to as negative lapse rate feedback.
The hypothesised positive water vapour feedback, where water vapour accumulates specifically in the upper troposphere (200 to 300 hPa), due to negative lapse rate feedback, & doubles or triples the direct effect from CO2 (in the models) also increases the negative lapse rate feedback further.
IPCC
Because the water vapour and temperature responses are tightly coupled in the troposphere (see Section 8.6.3.1), models with a larger (negative) lapse rate feedback also have a larger (positive) water vapour feedback.
Here’s the IPCC climate model projection showing how ( C ) “well mixed greenhouse gasses” & no other forcing, warms the upper tropical troposphere (200 to 300 hPa)

Now, as I showed the other day, the UAH satellite data, as well as RSS sat data & weather balloon data all show that the surface has in fact warmed faster than the upper troposphere.
This is the opposite of what would have occurred if the warming was forced by greenhouse gasses, & positive water vapour feedback (the strongest feedback by far)
This is irrefutable proof that the warming is at the most, only partially due to greenhouse forcing, or none of it is due to greenhouse forcing & is all natural.
It’s likely that the demonstrated decrease in upper tropospheric water vapour has totally offset the increase in CO2.
Atmospheric Moisture
Atmospheric Relative Humidity

Atmospheric Specific Humidity

Now, relax & enjoy the interglacial
and don’t forget that
