by K. Richard, Nov 24, 2022 *in NoTricksZone*

## German physicists claim to have experimentally demonstrated the greenhouse effect from greenhouse gases like CO2 and CH4 is a real phenomenon, but assess the climate sensitivity to a doubling of CO2 with feedbacks is “only ECS = 0.7°C … 5.4x lower than the mean value of CMIP6 with ECS = 3.78°C.”

“The derived forcing for CO2 is in quite good agreement with some theoretical studies in the literature, which to some degree is the result of calibrating the set-up to the spectral calculations, but independently it determines and also reproduces the whole progression as a function of the gas concentration. From this we deduce a basic equilibrium climate sensitivity (without feedbacks) of ECSB = 1.05°C. When additionally assuming a reduced wing absorption of the spectral lines due to a finite collision time of the molecules this further reduces the ECSB by 10% and, thus, is 20% smaller than recommended by CMIP6 with 1.22°C.”

“Detailed own investigations also show that in contrast to the assumptions of the IPCC water vapor only contributes to a marginal positive feedback and evaporation at the earth’s surface even leads to a significant further reduction of the climate sensitivity to only ECS = 0.7°C (Harde 2017 [15]). This is less than a quarter of the IPCC’s last specification with 3°C (see AR6 [1]) and even 5.4x lower than the mean value of CMIP6 with ECS = 3.78°C.”

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