Review Comments

The manuscript is based on a very important topic of the Climate Change in the High Mountain Asia using CMIP6 data for temperature, snow cover and precipitation. Different observed and reanalyzed data were used for the different parameters in the study to get the most appropriate picture. The authors here attempt to address performances of 26 CMIP6 GCMs over HMA for the historical period 1979-2014 and the future projections. 10 models were considered for the future projection and related analysis based on the availability of the 4 SSPs scenarios (SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5) to estimate the anthropogenic emissions. The results may have some implications for the academic community. However, there are several areas where the manuscript can be improved. I have few comments that I am giving below:

Minor comments

1. Use the term either “Snowpack” or “Snowcover” (L: 58).
2. L: 89 sentence “Sections 6 ….” Should be restructured”.
3. Meaning of the sentence in L: 220 “Whenever possible……” is not clear. What are other datasets?
4. A little more elaboration on the temperature is required in Section 3.2 to put light on the obtained results in the study.
5. Sentence “For temperature, ERA-Interim…….” (L: 252-254) is not in the flow of the preceding text and therefore need elimination from the manuscript.
6. Use either “Sect.” or “Section” in different paragraphs of the manuscript.
7. Why is the in-depth discussion on APHRODITE missing in this Section 3.2 ?
8. More description in Section 3.3 on the temperature, snow cover and precipitation is required to show the bias.
9. Sentence “Correlation between temperature and snow cover……..” (L: 300-303) should be part of Section 3.4.
10. Rather than temperature only, section heading of Section. 3.3 needs to reflect the snow cover as well as precipitation. Add more text in Section 3.3 for the discussion on precipitation.
11. Which test was adopted for the significance of the correlation and how was the level of significance selected to declare the value significant ?
12. Mention the threshold limit selected to declare the trend results significant in Section 4.1.
13. Comments on the figure and the tables have not been made at my end. Please add it!

Review of “Climate change in the High Mountain Asia in CMIP6” by Lalande et al.

General comments:

In this paper, the authors present their analyses of historical and future scenario simulations of CMIP6 models over High Mountain Asia (HMA). A major limitation of such studies in the region is the sparsity of long observational records. However, it is important to understand the regional climate change over HMA regions as the glaciers and snow over the region and how they change in the future will play a major role in regional hydrology. The authors attempt to understand the historical biases and how they are related to the historical and future trends in CMIP6 model simulations. The work is interesting, and the paper is well written. I have a few comments that need to be addressed before accepting the paper.

 Specific comments:

1. Introduction, L35: “As a large mid-tropospheric heat source…” The role of the Tibetan Plateau as a heat source for monsoon is a debated topic. Authors may refer to Boos and Kuang (2010; Dominant control of the South Asian monsoon by orographic insulation versus plateau heating. Nature 463, 218–222 (2010). https://doi.org/10.1038/nature08707)
2. Taylor diagram is a useful tool in multi-model inter-comparison, especially when the models are compared with respect to the observations. I suggest that the authors use Taylor diagrams to compare temperature, precipitation, snow cover, etc. simulated by the models.
3. Figure 6.: I suggest that the authors can try showing the agreement among the models in the sign of the trend in this figure. The hatching is often used to show statistically significant trends and not otherwise. Authors may try using contours for not significant trends, shading for significant trends, and hatching for points where > 60 % of the models agree on the sign of the trend.
4. Figure 9: “2081-2010” in the caption should be 2081-2100”.