As a common note to all reviewers, we thank them for their constructive comments, and for directing us to relevant parts of the literature that we overlooked. We made considerable revisions to address overarching concerns related to: (i) the use of a (too) simple model; (ii) insufficient specificity in the methodology; (iii) lack of discussion related to apparent differences with the existing literature. We also benefited from, and adopted numerous suggestions for improving the presentation throughout.

> 1. Lack of clarity and coherence in title, abstract and the contents [...]

Section 1 and 2 have been substantially rewritten to address the concerns arising from the interpretation of the admittedly simple approach, and lack of precision in the use of terminology and in the description of the methodology.

We also decided to change the title to "A conceptual framework for understanding longwave cloud effects on climate sensitivity" to both highlight the conceptual methodology of the study and to avoid confusion with existing literature on cloud masking.

> 2. In the methodology part, the method is not well docoumented [...]

The methodoloy section now clearly describes the chosen relative humidity RH profile and how it is computed in different background climates. In addition, the way that (optical) cloud parameters are chosen for the different ensemble members is explained in more detail.

> 3. [...] How does the cloud masking effect connect with the fixed-cloud albedo hypothesis?

The substantial rewriting of Sections 1 and 2, as well as the discussion, aims to better introduce the scope of this study and the terminology used. In this case, for example, the assumption of a fixed cloud albedo is necessary to disentangle effects that arise purely from changes in cloud top temperatures. These changes are implemented according to idealised mechanisms (FAP, FAT, PHAT) that link the cloud top height (temperature) to the thermodynamic profile in a well-defined way.

> 4. The writing and presentation need improvement. [...]

The suggestions related to the presentation have been incorporated in the revisions.

As a common note to all reviewers, we thank them for their constructive comments, and for directing us to relevant parts of the literature that we overlooked. We made considerable revisions to address overarching concerns related to: (i) the use of a (too) simple model; (ii) insufficient specificity in the methodology; (iii) lack of discussion related to apparent differences with the existing literature. We also benefited from, and adopted numerous suggestions for improving the presentation throughout.

> For the most part, I found the study to be an interesting and enjoyable read. However, I was confused by some of the terminology and methods, and the final section of the paper introduced a lot of new ideas in quick succession which I found hard to follow. I agree with many of the comments posted by the first anonymous reviewer.

Thank you for the detailed and positive feedback. Section 1 and 2 have been substantially rewritten to address the concerns arising from the lack of precision in the use of terminology and in the description of the methodology.

> Figure 3+4: Use the caption to explain what you mean by “No high cloud” etc

Done.

> L34: I think this requires fixed relative humidity in temperature coordinates ?

Yes, that's correct. Our simulations prescribed a fixed RH(T) relation and this is now more clearly stated in the methodology.

> L37: incorrect year of Jeevanjee paper

Fixed.

> Table 1: Just write out the numbers again rather than using apostrophes

We think the apostrophes help to emphasise when numbers do not change. We explain this notation in the caption.

> L87: How do you determine the convective top?

It is simply the first level that doesn't need to be convectively adjusted anymore, i.e., the radiative equilibrium profile is stable (or warmer) than the moist adiabat rising from the surface. We have revised the text to make this more clear.

> L94: Do you include prescribed ozone? This may affect the high clouds through artificial warming of the anvil layer

Yes, we do include a fixed ozone profile following the RCEMIP protocol. It is true that this has an impact on the temperature profile in the tropopause region. However, our high-clouds are still located in the "covective" part of the troposphere. Therefore, their temperature change should solely depend on the moist-adiabat and the radiativelt driven divergence.

> L102: This is not what “PHAT” stands for in the literature, please change this abbreviation. Also, although this isn’t stated explicitly, it seems like your high clouds don’t actually maintain a fixed anvil temperature (alluded to in L200)? The level of maximum clear-sky convergence should remain roughly around the same temperature, no? It would be helpful if you clarified this.

We included the proper long name and references for "PHAT". The level of maximum clear-sky convergence warms roughly at a rate of 0.2 K/K.

> L143: You state that the ensemble mean is within the CERES range, but you don’t actually show this anywhere. Could you include this in Figure 3?

Yes, we agree that this would be useful and we added the CERES reference values to the Figure (x-ticks and caption) and the text.

> L162: suggest amending to something like: “…can no longer be reconciled with the CERES data, and thus we do not plot bold lines in Figure 3 for the ‘no high clouds’ case.”

Done.

> L194: Why do you use such a big temperature increment? dT=6K feels somewhat arbitrary. I doubt it affects the results, but it was a bit distracting to me at first.

The somewhat large dT is used to get a clear signal in cloud-top changes. As the cloud-top is always tied to one distinct model level it also can only rise in steps of full model levels. As a consequence, for a small dT some ensemble members might see no change in cloud-top at all. Using a larger dT ensures a clearer signal in cloud-top height while not changing the qualitative results. We also added this explanation to the methods section.

> L205: I am missing something. I thought including Planckian clouds (BL ones) would increase the magnitude of \lambda? By allowing emission from wavenumbers where water vapor is optically thick? This is what Fig1 (final row) seems to suggest…

This effect is visible in Fig 4., where \lambda is decreased in the absence of low-level clouds (Planckian clouds), or vice versa, the presence of low clouds increases the magnitude of \lambda.

> Section 4: This section, up to L223, on the masking of surface albedo changes was confusing to me. I struggled to understand how you got to these numbers and how they relate to the idealized RCE calculations you presented earlier.

The discussion section has been rewritten to address this and other conerns raised in other reviewer comments.

> L250: This isn’t considered in the final calculations presented in Figure 4 though, right?

Correct, this is just a back-of-the-envelope calculation to put the results into perspective.

As a common note to all reviewers, we thank them for their constructive comments, and for directing us to relevant parts of the literature that we overlooked. We made considerable revisions to address overarching concerns related to: (i) the use of a (too) simple model; (ii) insufficient specificity in the methodology; (iii) lack of discussion related to apparent differences with the existing literature. We also benefited from, and adopted numerous suggestions for improving the presentation throughout.

> A general concern is that the model setup is too idealized to be taken seriously for understanding the climate and its sensitivity in reality. [..]

> The current paper offers too little information from the experiments for readers to understand and appreciate the results and conclusion. 

Sections 1 and 2 have been substantially rewritten to address concerns arising from the interpretation of the admittedly simplistic approach. This rewriting makes a particular effort to motivate the idealised study, and present its limitations. We agree that the model setup is too simple to derive quantitative results directly comparable to reality. However, the goal is to understand how the (vertical) distribution of clouds in temperature space affects the radiative response, which requires a well-defined thermodynamic state.

> [...] Moreover, as showed by Huang et al. (DOI 10.1038/s41597-024-03080-y) showed, OLR changes apparently differ dramatically in different regional climates and noticeably deviate from Simpsonian response.

We agree that the actual changes in OLR with temperature depend on subtelties of atmospheric composition. For example, even small changes in RH will result in a radiative response that is very different from a Simpsonian (non-)response. The strength of an idealised modelling strategy, as in our study, is that it can test specific hypotheses, in our case the role of different (but plausible) changes in cloud in temperature space, while keeping their albedo constant.

> Can and need the simple model represent such reality? This ought to be considered and discussed in relevance to these papers.

We would argue that it cannot represent such reality but that is also does not need to give answer questions in the scope of this study. We hope that the substantial rewriting of the introcution and discussion now better communicates this point.

> Eq. 1: is this right? Sum or product?

The symbols in both equations are correct, we take the product of individual changes in Eq. 1 and sum over the fluxes in Eq. 3

As a common note to all reviewers, we thank them for their constructive comments, and for directing us to relevant parts of the literature that we overlooked. We made considerable revisions to address overarching concerns related to: (i) the use of a (too) simple model; (ii) insufficient specificity in the methodology; (iii) lack of discussion related to apparent differences with the existing literature. We also benefited from, and adopted numerous suggestions for improving the presentation throughout.

> However, I feel this manuscript could do a much better job in citing the relevant literature (only one cited reference was published after 2021 [...]

We appreciate the reviewers list of more recent literature, which we happily included to the manuscript.  The lack of post-2021 literature was due to the fact that most of the manuscript was written in 2021 and for a vareity of reasons was put aside before being in late 2024.  When finishing we made the mistake of only updating our own manuscript in the references.  Please forgive this oversight.

> L142, 162, and Figure 3 - Perhaps I missed it, but are the observed CERES values of CRENET, CRESW, and CRELW explicitly stated or plotted anywhere? Doing so would help the reader evaluate the fitness of the simple model.

Thanks for the catch. The numbers are now included in the Figure 3 and the text.

> L251 This is an interesting finding and I would appreciate a bit more discussion on what this tells us about previous studies and what it means for future studies. For instance, can it explain Raghuraman et al 2023 which showed a near-zero trend in the net CRE over the past 20 years? How can this insight help us to better interpret observations? Etc.

Thanks.  As noted above, we had mostly finished the manuscript before the Raghuraman study was submitted and failed to catch up with the literature in between this point and the submission some years later.  Raghuraman et al 2023 show a cooling trend from changing LW CRE. Our analysis leads us to expect a warming (amplifying)  effect from the radiative response to warming, and a cooling effect from the masking of the radiative forcing, with the latter being somewhat stronger.  Raghuraman et al also measure a cooling effect consistent in sign, but  larger in magnitude than what we would have expected.  Because the shortwave effect is opposite, the discrepancy, is likely associated with changes in cloud fraction, wich our model does not consider.  We have expanded our discussion to put them in the context of earlier findings by Raghuraman et al. 

is very relevant and we have elaborated our disucssion to better address this important study.

> L99 Perhaps it should be “fixed cloud pressure” rather than “fixed anvil pressure”, since you’re talking about low clouds?

> L101 Perhaps it should be “fixed cloud temperature” rather than “fixed anvil temperature” since you’re talking about mid-level clouds?

We decided to stick to the term anvil to refer to the cloud top region, as it allows consistency with existing terminology for high clouds. We added a footnote to explain this choice and hopefully avoid confusion.

> L103 PHAT should be defined

Done.

> L142 It looks like it is between -83 W/m^2 and -28 W/m^2. Perhaps you could differentiate the minus sign from the dash more clearly? Or write it as [-83, 28] W/m^2?

Done.

> L197 - 200 I would appreciate seeing a plot of the cloud fraction profiles (at Ts=285, 291 K) as a function of temperature

As the cloud fraction is kept constant between simulations at different Ts, a plot as a function of T (or height) seemed to obscure the relevant numbers. However, we see that the change in cloud top temperature for the different cloud types is of interest, and is therefore shown in the table below:

As a common note to all reviewers, we thank them for their constructive comments, and for directing us to relevant parts of the literature that we overlooked. We made considerable revisions to address overarching concerns related to: (i) the use of a (too) simple model; (ii) insufficient specificity in the methodology; (iii) lack of discussion related to apparent differences with the existing literature. We also benefited from, and adopted numerous suggestions for improving the presentation throughout

> The paper uses an idealized framework to make progress toward a simple derivation of all-sky climate sensitivity. I like the idea, but I think the simplicity of the set up may be hampering the realism of the values.

Thank for the general intereset in the idea. We agree that the quantitative results of this study are hard to compare to the real Earth. However, the goal of this study is to understand (some of) the underlying physical mechanisms in a clearer way. An idealised model is helpful for this purpose, something we now try to better motivate through a rewriting of sections 1 and 2, as well as the discussion .

> [...] How do the authors reconcile their results with the past work? Could you provide the LW and SW breakdown? Additionally, could you provide the masking due to specific terms such as water vapor, surface temperature, surface albedo, etc.?

The discussion has been revised to address differences to previous studies, especially apparent differences in the sign of important terms.  The apparent discrepanceies weree due to different definitions of masking, and some uphysical effects that arise from the assumption of unphysical states as the reference for feedback studies. 

> L35: This “Simpsonian” response is stated as a fact of matter, when in reality, emission does change with warming in bands outside of the window (Feng et al., 2023; Koll et al., 2023). Altogether, atmospheric emission contributes ~40% to the global-mean clear-sky longwave feedback parameter due to contributions from water vapor’s rotational and rotational-vibrational bands and other greenhouse gas bands such as CO2, CH4, N2O, O3 (Raghuraman et al., 2019, 2023b).

We agree that the Simpsonian response doesn't hold in many real-world scenarios. However, we argue that the reason for this is that the prerequisites, in particular the constancy of RH, are not met. Even subtle changes in RH will lead to noticeable changes in OLR in supposedly Simpsonian parts of the spectrum. The rewrite of the Discussion section makes it clearer that this imposes limitations on how far our results can (and should) be compared quantitatively to the real world. However, we remain convinced that a well-defined idealised model helps to disentangle contributions from cloud top changes.

> L100: Please provide more details on why mid-clouds follow FAT while high-clouds follow PHAT. The latter is well documented but providing some references and explanations for the former would help the reader.

Two references are now provided for mid-level clouds following FAT, one is the paper by Stevens et al (2017) which associates their accumulation with processes at the melting level (what those authors call the first mover hypothesis), the other is a very interesting and recent paper by Spaulding and Mitchell (AGU Advances 2025) which makes a radiative argument for them appearing at water vapor specific humidities typical of the freezing level.