It's presented as a fact check of an article on The Daily Sceptic, but in reality that article is reporting on the conclusions of several scientific papers, triggered by this one [1] published by a trio of Polish researchers. That paper goes into more detail on the underlying physics than ClimateFeedback's own explanation does, which isn't really mentioned until the very end. ClimateFeedback really should link directly to the sources of the claims they're arguing with.

After reading the ClimateFeedback article, the comments from climatologists, the Daily Sceptic post and scan reading the Kubicki paper, I can't quite work out what they think they're disagreeing with. All sources agree that CO2 impact is logarithmic, i.e. doubling CO2 concentration doesn't cause a linear increase in temperature. The argument seems to be some sort of semantic dispute over whether a logarithmic function can ever be said to truly saturate or stop growing. That is clearly uninteresting. What matters is the actual curves and the actual impact in reality.

This problem appears explicitly in the paragraph after figure 5:

> It is worth noting that although the slope becomes more gradual, the resulting global warming is still predicted to have negative consequences for humans and ecosystems. As explained by the IPCC, “risks and projected adverse impacts and related losses and damages from climate change escalate with every increment of global warming.”

"damages ... escalate with every increment of global warming" is a very unclear statement. They jump from arguing concrete facts about physics to vague statements about damages without any kind of quantities attached.

They also say the claim they're debunking isn't precise enough due to not taking into account altitude, but again, the Kubicki paper they're actually arguing with does acknowledge this fact multiple times [2]. This seems like arguing with a strawman, or worse, that they haven't actually read the thing they're trying to debunk.

Finally, the Kubicki paper is actually making the more general argument that the various factors that affect the climate system (e.g. clouds, wind speeds) aren't well understood enough to make accurate predictions of the CO2-temperature link, and more experiments should be done to establish accurate physical data to feed into the models. The Daily Sceptic also claims that the function mapping CO2 levels to temperature (which is in turn not the same thing as damages) isn't known, and estimates vary drastically.

In the comments the invited climatologists seem to accept that this problem does exist but downplay it, saying only that their "best estimates" have a CI from 2 to 5 degrees. Haigh weighs in and says The gratuitous statement that these are “little more than guesses” couldn’t be further from the truth but then also the wide range results from uncertainties which is just a rephrasing. Also if you drop outliers (which the Daily Sceptic isn't doing but the IPCC does) then you can make your confidence seem arbitrarily high, but when the whole thrust of the article is about how expert climatologists are it doesn't seem fair to exclude some, just because their calculations are further from the mean.

[1] https://www.sciencedirect.com/science/article/pii/S266649682...

[2] "It should be noted that CO2 absorption lines at different altitudes are narrower than CO2 absorption lines under atmospheric pressure", p6 and "it should be noted that unlike the used cuvette, the vertical
structure of the atmosphere undergoes changes in both pressure and temperature", p5