Another observational analysis finds the shortwave effect of clouds is the “dominant term of the recent increase in absorbed solar radiation,” explaining the 2001-2024 warming. [emphasis, links added]
According to the authors of a new study, clouds are the primary modulators of the Earth’s shortwave and longwave radiation.
Thus, the radiative effects of clouds “play a crucial role in determining the Earth’s energy balance” and “dominate the radiative balance trends.”
Satellite observations indicate that from 2001-2024, there was a 0.45 W/m² per decade increase in solar radiation reaching the Earth’s surface.
This one W/m² rising trend in absorbed solar radiation was primarily caused by declining cloud cover.
“The increase in the absorbed solar radiation is driven primarily by a decrease in the reflection of SW radiation by clouds.”
The shortwave cloud radiative effect (SWCRE) is thus regarded as the “crucial missing piece” in explaining 21st-century warming.
“[C]hanges of only a few percent in the relative coverage of the [cloud] regimes produce large cloud radiative signatures that can dominate the radiative balance trends”
Read more at No Tricks Zone
Summer started a week ago but ours was more like Winter or Late Fall
60% of the global warming since 1975 is TMIN, which is not affected by clouds.
40% of the warming since 1975 is TMaX, which is affected by clouds and reduced atmospheric pollution. There’s no way to differentiate between these two factors that cause TMaX warming.
The conclusion of this study is false and not supported by accurate data.
The only conclusion possible is that some warming since 1975 was caused by a smaller percentage of cloud cover in the past 25 years.
But not most of the warming.
The change in cloud cover percentage is actually too small to be statistically significant.
I’m just assuming that it is.
Less cloud coverage would cause warmer days and cooler nights. We do have warmer days, but the nights have been warming faster than the days. The primary cause of warmer nights is CO2 emissions.
Nikolov and Zeller’s 2024 paper
came to same conclusion. Reduced albedo and hence higher solar radiation accounting for all 21st century warming. Any warming from a supposed GH effect doesn’t exist.