The authors aimed to review on direct and indirect contributions of sulfate to methane oxidation in upland soils. As far as I’m concerned, influence of sulfate on methane oxidation is an important topic in biogeochemistry, but the current manuscript failed to make a clear and concise presentation. Here I list my major concerns as follows.

1) Methane oxidation or aerobic methane oxidation?

The manuscript is entitled ‘Contribution of sulfate to methane oxidation...’, but throughout the manuscript the authors seemed to talk only about aerobic methane oxidation. Note that both aerobic and anaerobic methane oxidation exist in upland soils. If the authors just want to review on aerobic methane oxidation processes, please change the title into ‘…Contribution of sulfate to aerobic methane oxidation…’. If not, previous studies regarding anaerobic methane oxidation should also be reviewed in the manuscript.

2) Direct effects?

The authors stated that ‘This review provides a comprehensive summary of the direct and potential indirect impacts of SO₄^2- on CH₄ oxidation’ (L. 82 - 84), but I cannot see how sulfate directly influences methane oxidation in the manuscript. It seems that the authors tried to figure out the direct effect in the third part of the manuscript (L. 186 – 250), but they only concluded that ‘due to the scarcity of studies investigating the direct effect of SO₄^2- on CH₄ oxidation, no definitive conclusion regarding its impact could be drawn’ (L. 245 - 247).

Before discussing direct impacts of sulfate on methane oxidation, the authors should first answer whether sulfate could directly influence methane oxidation. Unfortunately, the authors didn’t even try to demonstrate existence of direct influence of sulfate on methane oxidation, but they made a conclusion that they provided ‘a comprehensive summary of the direct and potential indirect impacts’. Therefore, I think the conclusion regarding direct impacts should be modified throughout the manuscript.

From my perspective, direct effects of sulfate on methane oxidation is associated with coupling of anaerobic methane oxidation to sulfate reduction. Under anoxic conditions, numerous studies have demonstrated that sulfate could be the electron acceptor for methane oxidation, which can be considered a direct effect of sulfate on methane oxidation. However, the authors didn’t review on aerobic methane oxidation in the current manuscript.

3) Concerns regarding the major conclusion

From table 1, the authors drew the conclusion that ‘the enhancement of SO₄^2- on CH₄ oxidation is prominent in numerous studies’ (L. 74) and that ‘SO₄^2- facilitates CH₄ oxidation within a range of 3-42%’ (L. 75). However, table 1 only contains results from 5 study sites, and no effect of sulfate addition was observed in 2 out of the 5 sites. In the 5 sites, effects of sulfate addition are 0%, 0%, 3%, 25% and 42%, respectively, and no statistical analysis has been conducted to support the statement that sulfate facilitate methane oxidation by 3-42%. Therefore, I think this conclusion is greatly undermined because of insufficient literature and lack of effective statistics. Additionally, title of table 1 is ‘Promotion effect of sulfate on methane oxidation in diverse biome soils’, but I don’t think 5 forests could be called “diverse biome”.

4) Concerns regarding manuscript structure

I also have some concerns regarding structure of the manuscript. First, the authors spent 2 pages introducing the methane oxidation processes and associated microbes (Pages 4 - 5), which are not much associated with the main topic of the manuscript. These contents are not reviewed in the following parts, and I suggest the authors to shorten these contents. Second, Lines 174 – 182 in section 2.3 repeated contents in the introduction (Lines 60 - 68). Similar sentences also emerged in the implication section (Lines 355 - 360). Third, contents in section 3 are disorganized, and I suggest the authors to reorganize these contents (e. g. by adding a topic sentence to the beginning of each paragraph of this section). Forth, presentation of table 1 (L. 75 - 78) should be in the result section (e.g. section 3), instead of the introduction.

Minor points:

1. Omission of conjunctions. Grammatically, clauses should be joined by conjunctions, but conjunctions in many places are omitted in the manuscript, especially in the abstract. For example, Lines 16, 20, 21 and 26.
2. There should be no line feed in ‘Norway Scots Pine forest’ in Table 1 (the first column, the forth row).

The authors aimed to review the recent literature regarding the impact of sulfate on aerobic methane oxidation in soils. Indeed, this is in interesting biogeochemical topic, given that in the past the focus was on the role of SO₄^2- on anaerobic methane oxidation. I am in agreement with the first reviewer that the current manuscript failed to present the state of knowledge in a clear way and although this is a mini-review, it lacks depth. At the current state, for me, the aim of this manuscript is to show how little research has been done on the influence of sulfate on aerobic methane oxidation and not to summarize the research to date into an overall picture (review) and to point out specific starting points for further studies (syntheses). If I have understood correctly, the authors are currently working on another manuscript including experiments to observe the effects of SO₄^2- on aerobic methane oxidation. By shortening the text considerably and formulating it more precisely, it would be ideally suited as an introduction and part of the discussion for such a manuscript.

In the following, I have outlined my major points for each section and provided more detailed feedback in the comments of the attached document.

1) The introduction would benefit from enhanced clarity, with the relocation of sections from section 4 having the potential to significantly improve its quality. However, the text does not provide a compelling rationale for why the impact of SO₄^2- on aerobic methane oxidation could be of interest. Furthermore, some of the references utilized (marked in the PDF) do not correspond to the original works cited in the text, and some references are employed incorrectly.

2) It is imperative to briefly outline the pathway through which methane is oxidized by methanotrophs, highlighting the genera responsible for this process. However, the focus should be on the enzymes that may be influenced by sulfate, either directly or indirectly, through changes in pH. Additionally, it would be intriguing to examine the effects of sulfate on changes in the methanotrophic community or their abundance. If these aspects are not addressed, it would be advisable to combine and significantly shorten these sections. The topic of high and low affinity methanotrophy is not addressed at all, despite the fact that this distinction is very important because high affinity methanotrophs mainly oxidize atmospheric methane, whereas low affinity methanotrophs focus on the methane produced in the soil. If the authors want to argue that sulfate addition increases the atmospheric soil sink, this is of utmost importance, especially as some of the indirect effects may only target one of the two groups. For instance, the inhibition of methanogenesis would primarily affect the oxidation of methane by low-affinity methanotrophs, while the atmospheric sink may remain unaltered.

In addition, the methanotroph types are nowadays only defined by phylogeny and not as mentioned by their metabolic pathways, membranes etc.

Most of section 2.3 can be moved to the introduction and the rest should be discussed in sections 3 or 4.

3) I find the titles of section 3 and 4 misleading, as most of the processes described in section 3 are indirect effects of SO₄^2- on methane oxidation Moreover, a substantial portion of the argumentation appears to suggest that the primary effect of the sulfate is to mitigate the inhibitory effects of the ammonium. However, it is subsequently presented as that sulfate increases methane oxidation rates. This should be clarified.

4) This section provides a description of the various soil properties that may be influenced by SO₄^2-, yet the processes by which these properties are influenced are only described in rudimentary terms and often unstructured. The impact of SO₄^2- is often speculated. Consequently, this section lacks in depth and needs to be reworked. Furthermore, the sections 5 and 6 should be reworked and combined.