We thank all three reviewers for their efforts to improve our manuscript, and find their recommendations very helpful. We believe most comments to be minor, which can easily be addressed in the text. Here, we provide descriptions for addressing the larger comments and suggestions of RC1:

First, all three reviewers highlight a need to more clearly describe geological conditions within the study catchments. As geochemical weathering is a fundamental idea concerning a sink of carbon dioxide within this manuscript, we agree that expanded descriptions and analyses of catchment geology are appropriate. Following these suggestions, we have explored the dissolved cation data in more detail to explore geologic influences, and propose three key amendments to this manuscript as a result.

1) We will expand the Site Description to describe the diverse geology within all four catchments (starting line 128), which is typical of the Swiss Alps (Bucher et al., 2017; Pedrazzini et al., 2016). This includes mores specific lithologies of each catchment in the text near Line 128 and in Table 1.

2) At the suggestion of both RC1 and RC, we have quantified the median concentration of major cations and anions in a supplementary table, and quantified key cation ratios to examine how stream chemistry is affected by lithology within the catchment (Torres et al., 2017). The description of dissolved ions will be added to the Methods near Line 167, and the analysis will be added near Line 299.The preliminary figure of this analysis is shown at the bottom of this comment. This analysis reveals relatively large influence of carbonate weathering on stream water chemistry within all four catchments, despite carbonate not necessarily being the dominant lithology. The Results will be listed near Line 357.

3) Interpreting this analysis provides important context for the discussion, in which weathering potential within our catchments can be compared to each other and to other glacier-fed streams globally (Torres et al., 2017). This will be expanded in the Discussion starting near Lines 465 and 553. With carbonate as the seemingly-dominant lithology with respect to geochemical weathering in our catchments, this suggests a) there may be a relatively elevated geochemical sink of CO₂ compared to glacierized catchments of lower carbonate content (i.e., most other glacier fed streams in Torres et al. (2017)); and b) despite different dominant lithologies, the relatively similar cation ratios in our four catchments suggests weathering of carbonates is the dominant process across all 12 sites. While we do not have the data to more closely examine geologic difference across our watersheds, this analysis provides evidence for the disproportionate influence of carbonates in catchment weathering and can more directly identify key opportunities for future research to robustly examine geologic variability in our study areas.

Secondly, RC1 highlights an opportunity to clarify the related nature of soil development and vegetation cover (Klaar et al., 2015; Khedim et al., 2021; Wietrzyk-Pełka et al., 2020; Wietrzyk et al., 2018). We agree there should be more discrete explanation of these processes and their relation to carbon dynamics in mountain catchments, and as RC1 suggests, will acknowledge as much and clarify near Lines 84 and 425. Of particular relevance is the accelerated accumulation of soil organic carbon following plant establishment. If true in our study catchment, the establishment of plants may lead to a relatively rapid increase in soil respiration and export of both DOC and CO₂ to the stream. Unfortunately, data on the vegetation types of these alpine catchments is limited. In general, vegetation cover is limited to grasses and herbaceous plants. We hypothesize that in these catchments, as the RC1 guesses, that total biomass and soil development are more important than vegetation type. However, we agree this could become an important variable at lower elevations or with continuing vegetation succession.

Finally, RC1 suggests analyzing temporal patterns within the data, both seasonally and year-to-year. Some temporal analyses have been reported previously for these streams, specifically for CO₂ (Horgby et al., 2019) and DOC (Boix Canadell et al., 2019). We will more clearly highlight these previously described patterns, and the importance of seasonal patterns in glacier fed stream generally (Bergstrom et al., 2021) within the text near Line 553. As RC1 highlights, our desire is to describe broad patterns, and we further suggest that a robust analysis of the temporal patterns within the data warrants an independent manuscript. As such, we do not propose to include analysis of temporal patterns, but will more clearly acknowledge the importance of temporal dynamics, especially with regards to seasonal melting of the glaciers. This will keep focus on the central theme of the paper, which is alterations to the organic and inorganic carbon dynamics of streams along a glacier cover gradient.

We thank all three reviewers for their efforts to improve our manuscript, and find their recommendations very helpful. We believe most comments to be minor, which can easily be addressed in the text. Here, we provide descriptions for addressing the larger comments and suggestions of RC2:

First, all three reviewers highlight a need to more clearly describe geological conditions within the study catchments. As geochemical weathering is a fundamental idea concerning a sink of carbon dioxide within this manuscript, we agree that expanded descriptions and analyses of catchment geology are appropriate. Following these suggestions, we have explored the dissolved cation data in more detail to explore geologic influences, and propose three key amendments to this manuscript as a result.

1) We will expand the Site Description to describe the diverse geology within all four catchments (starting line 128), which is typical of the Swiss Alps (Bucher et al., 2017; Pedrazzini et al., 2016). This includes mores specific lithologies of each catchment in the text near Line 128 and in Table 1.

2) At the suggestion of both RC1 and RC, we have quantified the median concentration of major cations and anions in a supplementary table, and quantified key cation ratios to examine how stream chemistry is affected by lithology within the catchment (Torres et al., 2017). The description of dissolved ions will be added to the Methods near Line 167, and the analysis will be added near Line 299.The preliminary figure of this analysis is shown at the bottom of this comment. This analysis reveals relatively large influence of carbonate weathering on stream water chemistry within all four catchments, despite carbonate not necessarily being the dominant lithology. The Results will be listed near Line 357.

3) Interpreting this analysis provides important context for the discussion, in which weathering potential within our catchments can be compared to each other and to other glacier-fed streams globally (Torres et al., 2017). This will be expanded in the Discussion starting near Lines 465 and 553. With carbonate as the seemingly-dominant lithology with respect to geochemical weathering in our catchments, this suggests a) there may be a relatively elevated geochemical sink of CO₂ compared to glacierized catchments of lower carbonate content (i.e., most other glacier fed streams in Torres et al. (2017)); and b) despite different dominant lithologies, the relatively similar cation ratios in our four catchments suggests weathering of carbonates is the dominant process across all 12 sites. While we do not have the data to more closely examine geologic difference across our watersheds, this analysis provides evidence for the disproportionate influence of carbonates in catchment weathering and can more directly identify key opportunities for future research to robustly examine geologic variability in our study areas.

We thank all three reviewers for their efforts to improve our manuscript, and find their recommendations very helpful. We believe most comments to be minor, which can easily be addressed in the text. Here, we provide descriptions for addressing the larger comments and suggestions of RC3:

First, all three reviewers highlight a need to more clearly describe geological conditions within the study catchments. As geochemical weathering is a fundamental idea concerning a sink of carbon dioxide within this manuscript, we agree that expanded descriptions and analyses of catchment geology are appropriate. Following these suggestions, we have explored the dissolved cation data in more detail to explore geologic influences, and propose three key amendments to this manuscript as a result.

1) We will expand the Site Description to describe the diverse geology within all four catchments (starting line 128), which is typical of the Swiss Alps (Bucher et al., 2017; Pedrazzini et al., 2016). This includes mores specific lithologies of each catchment in the text near Line 128 and in Table 1.

2) At the suggestion of both RC1 and RC2, we have quantified the median concentration of major cations and anions in a supplementary table, and quantified key cation ratios to examine how stream chemistry is affected by lithology within the catchment (Torres et al., 2017). The description of dissolved ions will be added to the Methods near Line 167, and the analysis will be added near Line 299.The preliminary figure of this analysis is shown at the bottom of this comment. This analysis reveals relatively large influence of carbonate weathering on stream water chemistry within all four catchments, despite carbonate not necessarily being the dominant lithology. The Results will be listed near Line 357.

3) Interpreting this analysis provides important context for the discussion, in which weathering potential within our catchments can be compared to each other and to other glacier-fed streams globally (Torres et al., 2017). This will be expanded in the Discussion starting near Lines 465 and 553. With carbonate as the seemingly-dominant lithology with respect to geochemical weathering in our catchments, this suggests a) there may be a relatively elevated geochemical sink of CO₂ compared to glacierized catchments of lower carbonate content (i.e., most other glacier fed streams in Torres et al. (2017)); and b) despite different dominant lithologies, the relatively similar cation ratios in our four catchments suggests weathering of carbonates is the dominant process across all 12 sites. While we do not have the data to more closely examine geologic difference across our watersheds, this analysis provides evidence for the disproportionate influence of carbonates in catchment weathering and can more directly identify key opportunities for future research to robustly examine geologic variability in our study areas.

Secondly, RC3 requests some clarificaiton and more detail regarding soil development and vegetation, and we agree there is an opportunity to clarify the related nature of these ideas (Klaar et al., 2015; Khedim et al., 2021; Wietrzyk-Pełka et al., 2020; Wietrzyk et al., 2018). We agree there should be more discrete explanation of these processes and their relation to carbon dynamics in mountain catchments, and will acknowledge as much and clarify near Lines 84 and 425. Of particular relevance is the accelerated accumulation of soil organic carbon following plant establishment. If true in our study catchment, the establishment of plants may lead to a relatively rapid increase in soil respiration and export of both DOC and CO₂ to the stream. We will more clearly describe this in the text as suggested.