A new study finds the modeling-based claim that cloud cover changes are only responding to anthropogenic CO2 forcing as a feedback – and not functioning independently as a forcing – has (again) been contradicted by observations.
Since this is a water planet, and since clouds are formed when water vapor turns into water droplets, it is a tad disconcerting we are now being warned by the “expert” class that clouds may “disappear forever” as the Earth warms.
Image Source: indiatimes.com
Of course, even a casual observation of the seasonal cloud cover variations affirms that clouds increase in Arctic summer (warmer) and decrease in winter (cooler).
“Winter cloud occurrence…was 70%. It increased to over 80% the summer months and reached a 95% peak in September” (Maillard et al., 2021).
Image Source: Maillard et al., 2021
Further, a decline in cloud cover means more solar radiation is absorbed by the surface, leading to a net positive forcing (warming) because the shortwave effects of cloud albedo modulation exceed the longwave effects of clouds.
For example (staying with the Arctic), the increase in shortwave forcing associated with the decline in cloud cover in recent decades amounted to +7.3 W/m² positive imbalance from 1994-2017 over the Greenland ice sheet (Hahn et al., 2020). This is the dominant reason for the Greenland ice sheet melt over this period.
Image Source: Hahn et al., 2020
Now, another new study shows cloud cover clearly declined globally from 1983-2017. The mechanism driving the change in cloud cover is unknown, but other scientists have chalked it up to “internal unforced variability“.
The nearly 4 decades of falling cloud cover resulted in a net positive radiative forcing, heavily contributing to global warming over this period.
In contrast, IPCC climate models claim clouds only respond to (positive feedback) CO2 rise, or warming. But, as noted, the opposite occurs in observations: clouds increase as it warms, and increasing clouds leads to (net) cooling.
Therefore, the data clearly show “the cloud cover decrease could not have been caused by the increased surface temperature…and was not caused directly or indirectly by CO2” (Jonas, 2022).
So the models are wrong. Cloud feedback is negative. CO2 doesn’t cause the cloud changes, and thus an increase in shortwave forcing associated with a decline in cloud cover also occurs independently of CO2 or human influences. Consequently, “climate models and the IPCC over-estimate the effect of the atmospheric CO2 change.”
Save the Clouds!
Oh, wait. It also says they might become thicker.
Save the Blue Skies!
Will the clouds be thicker than those postulating this nonsense?
Can somebody explain me this paradox?
“But, as noted, the opposite occurs in observations: clouds increase as it warms, and increasing clouds leads to (net) cooling.
Therefore, the data clearly show “the cloud cover decrease could not have been caused by the increased surface temperature”
At the first paragraph, clouds increased. At the second paragraph, clouds decreased.
There is something I definitely don’t understand.
Thanks in advance.
Was Richard Feynman correct when he stated “Science is the belief in the ignorance of experts”? Of course he was correct, just digest the article above.
They are so smart that they just shot themselves in the foot.
They’ve “shot themselves in the foot” so many times, that it would be a wonder if they have any feet left.
science is settled…
clouds could disappear or become thicker..
it is so funny..being in denial only means changes caused by men are always bad..
even if you say , ha, may be models are ok, but you are optimistic.. you are a denier..
you must stop thinking and obey..
Global warming should cause the troposphere to hold more water vapor. Which would cause more global warming.
But there has never been runaway warming from that positive feedback.
A good theory is that with higher water vapor. there are also more clouds, blocking more sunlight, preventing runaway warming.
In Kelvin degrees, the estimated global average temperature since 1950 (rough estimate) has increased on;y +0.4%. That’s a small change. Perhaps the global average absolute temperature from 1850 through 2021 (Berkeley Earth) is self-regulated by our planet?