It so difficult to constrain errors in identifying the cloud impact on Earth’s radiation budget that the orders-of-magnitude smaller radiative impact of CO2 cannot be distinguished from noise.
According to a new study using CERES data, the observed biases in detecting the radiative effects of clouds on climate are 2.5 to 6.25 W/m² for longwave (LW) and shortwave (SW), respectively (Sun et al., 2022). Standard deviations in cloud radiative effects amount to 8 (LW) to 20 (SW) W/m². This variability and built-in estimation error wipes out the isolation of CO2 as a detectable factor in top of atmosphere (TOA) climate forcing.
This is because the cloud radiative effects (CRE) bias and standard deviation values are 15 to 100 times larger than the presumed cumulative surface radiative effects of CO2 forcing over a span of 10 years (0.2 W/m²).
Image Source: Sun et al., 2022
It has long been estimated that when clouds are present they dominate as the driver of greenhouse effect forcing. Quantitatively, the greenhouse effect of clouds is larger than a 100-fold increase in the CO2 concentration (~40,000 ppm).
Image Source: Ramanathan et al., 1989
The shortwave radiative effect of clouds is even larger, with ranges of ±300 W/m² (Sedlar et al., 2022). These values are 3,000 times greater than the total effect of CO2 surface forcing (0.2 W/m²) over a span of 10 years (Feldman et al., 2015).
Image Source: Sedlar et al., 2022
In other words, we might as well be guessing.
[…] Detection Of A CO2 Climate Signal In Radiative Forcing Is Again Foiled By Clouds […]
I’ll say it again. Cloud formation is a thermodynamically reversible process, meaning there can be no net energy flows at cloud level as a result of cloud formation. Not so for weather, which is a process for aiding the discharge of heat to space using increasingly chaotic mass and energy flows, thus increasing entropy. A more active sun will cause more active weather.
Ach! The mean old clouds!
(Thanks, Dylan Thomas)
As we seem to know nothing about the clouds, it seems rather arrogant to claim knowledge of causal relations driving climate.
Is this simular as Willis Eschenbach did on WUWT just a Week ago?
https://wattsupwiththat.com/2022/10/16/solar-sensitivity/
[…] Detection Of A CO2 Climate Signal In Radiative Forcing Is Again Foiled By Clouds […]
[…] Detection Of A CO2 Climate Signal In Radiative Forcing Is Again Foiled By Clouds […]
Wonderful post