The increasing climate suitability for human habitation on the Qinghai–Xizang Plateau

• Climate suitability index (CSI) was developed to assess climatic suitability. • CSI rose from 0.32 to 0.36 on the Qinghai–Xizang Plateau during 1979 to 2018. • Precipitation (61.42%) and temperature (17.22%) were the main drivers. • The Qinghai–Xizang Plateau’s climate will become more habitable by 2100. Global climate change is a pressing environmental challenge. Climate-induced migration highlights the severe impact of unsuitable climatic conditions. However, current research methods are limited in their ability to assess climate suitability for residents in high-altitude areas. In this study, we assess climate suitability across the Qinghai–Xizang Plateau from 1979 to 2018 and project future changes using four different shared socioeconomic pathway (SSP) climate scenarios by constructing the climate suitability index (CSI). The findings reveal a notable increase in CSI from 0.32 to 0.36 from 1979 to 2018. The primary factors contributing to the increased climate suitability are increasing annual mean precipitation (61.42 %) and decreasing solar radiation (17.22 %) from 1979 to 2018. Furthermore, the study forecasts a continued enhancement of climate suitability across all SSP scenarios, with SSP585 demonstrating the greatest improvement, followed by SSP370, SSP245, and SSP126. Although low oxygen levels at high altitudes remain a challenge, the overall improvement in climate suitability offers hope for people living at high altitudes to cope with climate change.