Weather

The clouds weren’t behaving the way the IPCC or the models said – Frustrated with that?


Michael Jonas

I’ve been working on cloud data for quite some time and now have a paper published on the behavior of clouds, which challenges the IPCC’s interpretation of clouds and in climate models. The IPCC indicates that clouds (1) provide a positive response to climate change (due to CO2) and (2) have responded to aerosols with an increasing cooling effect. The IPCC’s logic is essentially that man-made CO2 backed by #1 is already so strong that it gets past #2. My paper argues that clouds act largely independent of CO2 and have an effect. warming on par with CO2, maybe more. As far as I can tell from searching the scientific literature, this analysis has not been presented before.

Abstract:

Cloud activity patterns, both for cloud area and cloud optical thickness, were studied over the time period for which data is available, from 1983 to 2017. Cloud cover decreased during study period, while global surface temperatures increased. Cloud patterns and temperatures suggest a decrease in cloud cover that cannot be attributed to increased surface temperatures. The obvious implication is that the decrease in global cloud area must have been caused by some other unspecified factor rather than by CO2 directly or indirectly. Evaluation of changes in clouds and CO2 over the study period indicated that this unknown factor had a positive effect as much as an increase in CO2, on the amount of radiation reaching the surface (radiation forced ), and can have a much larger positive effect. Climate models, with no negative cloud or no effect on CO2-independent irradiance, need to take this into account in order to avoid overestimating the effects of CO2.

The article covers a large amount of the basis and is open source so anyone can read it, here. ‘Full text of the article in PDF‘open the whole paper.

First, I should point out that while scientific papers tend to go into ever more intricate detail, this research is still at a much higher level, dealing only with global numbers. or with global numbers broken down by land and sea. In other words, I am looking at the ‘forest’, whereas many scientific papers tend to look only at the ‘trees’. That is especially true for climate models, which attempt to build a picture of the ‘forest’ from all the individual ‘trees’ – an approach that is futile in my opinion, since no Are there any ‘trees’ that can be predicted more than a few days into the future.

The brief summary of the paper is as follows (NB. This is an abstract only, if you wish to disagree with it please do so by disagreeing with the article without an abstract):-

The available cloud data runs from mid-1983 to mid-2017 (34 years), so that’s the study period for the paper. Global cloud cover decreased during this period, while global surface temperature increased [Figure 1]. But if you look at the cloud and temperature patterns on shorter time scales (a few months), warmer temperatures cause more clouds, not less. [Figures 2, 3, 4]. Therefore, the decrease in cloud cover may not be due to increased temperatures. The cloud behavior should therefore be temperature independent, i.e. independent of man-made CO2.

The article continues to evaluate this independent cloud behavior [Figures 5, 6]. Specifically here is that the cloud area decreases, while the optical thickness of the cloud increases. But cloud area decreased very similarly over sea and land, while cloud thickness over sea increased more than on land. [Figures 7, 8]. The most likely explanation is that the increase in thickness at sea is not directly due to unspecified factor mentioned in the summary, but as a reaction to higher temperatures.

The conclusion is that the independent warming effect of clouds is comparable to that of man-made CO2, and possibly much larger. IPCC and models have no provision for this [Figure 9]. If models take this into account, it could help them avoid running too ‘hot’.

Not explicitly stated in the paper (which may be the case), although it is implied, is that if the models take this cloud behavior into account, the amount of warming from anthropogenic CO2 necessarily must become much smaller when the models are adjusted for the observed temperature. Therefore, the impact of man-made CO2 in the future will be much smaller.

Also omitted from the article were any attempts to identify unspecified factor reduces cloud cover. The simple reason is that I didn’t research it. I could have mentioned things like cosmic rays or solar ultraviolet (ultraviolet) rays as possible causes, linking them to the IPCC reports mentioning them, but I chose not to. It would just be pure speculation.

The paper explicitly stated that the model’s predictions were known to be highly unreliable (citing the reasons given in the IPCC reports), so there is no reason for that score. to not add a provision for standalone cloud behavior.

Those who like to see error bars all over the numbers will be disappointed. The reason is that the calculations are very approximate anyway, so the error bars would be meaningless. Final conclusion, “the same effect” and “could be a much bigger impact“Not the number anyway.

Note: I wrote previously on WUWT about cloud feedback:

That study was limited to oceanic regions. This paper starts with global data to make it more suitable for comparison with IPCC re-radiation enforcement.



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