**5. Conclusions**

The grassland NDVI in the Mt. Qomolangma National Nature Reserve and adjacent regions showed an overall increasing trend during 2000–2018. This increase is mainly attributed to precipitation rather than temperature or human activities (grazing). However, vegetation growth can also be simultaneously affected by grazing and/or temperature in some areas with relatively heavy grazing pressure, such as in Tingri and Dinggye counties. As a famous scenic spot in the world, the Mt. Qomolangma National Nature Reserve attracted a large number of tourists each year, which would stimulate the demands for livestock products, and cause an increase in grazing intensity and aggravate the negative impact on grassland ecosystems. Therefore, control of the number of tourists for Mt. Qomolangma, as well as that of livestock in Tingri County, will help improve sustainability development and reduce the adverse effects of grassland degradation caused by consistent warming.

**Author Contributions:** Conceptualization, L.Z., T.L. and W.Z.; methodology, W.Z.; software, W.Z.; validation, A. and H.W.; formal analysis, W.Z.; investigation, L.Z. and H.W.; resources, L.Z.; data curation, W.Z.; writing—original draft preparation, W.Z.; writing—review and editing, W.Z. and L.Z.; visualization, A.; supervision, L.Z.; project administration, L.Z.; funding acquisition, L.Z. and T.L. All authors have read and agreed to the published version of the manuscript.

**Funding:** The National Natural Science Foundation of China (41830649), the Key technology research and development projects in Xizang Autonomous Regions (XZ202101ZY0005G) and the Second Tibetan Plateau Scientific Expedition and Research (STEP) program (2019QZKK0301-1) provided financial support.

**Institutional Review Board Statement:** Not applicable.

**Data Availability Statement:** All data used in the manuscript are already publicly accessible, and we provided the download address in the manuscript.

**Acknowledgments:** We would like to thank the National Observation and Research Station for Qomolongma Special Atmospheric Processes and Environmental Changes, Tibet, China.

**Conflicts of Interest:** The authors declare no conflict of interest.

### **References**

