Accelerated contraction of future climate comfort zones in the southern subtropics: Insights from analysis and simulation of hiking big data

Many people are highly exposed to climate change through tourism activities. However, conventional evaluations of tourism climate suitability have consistently relied on uniform indicators. In reality, the combination of meteorological factors that tourists are sensitive to and the threshold ranges for their comfort vary across different climate zones. This study, for the first time, utilizes a dataset of 2,326,954 tourist behaviors in hiking to validate the differences in sensitivity to meteorological conditions among tourists in different climate zones and to assess the historical and future tourism suitability in various climate zones. The findings reveal the following key results: (1) The sensitivity of hiking activities to meteorological factors varies among tourists in different climate zones. For instance, tourists in the mid-subtropics and south temperate zones show a lesser sensitivity to precipitation, while those in the southern subtropics are less affected by temperature fluctuations. Tourists in plateau climate zones appear to be insensitive to both precipitation and average relative humidity. (2) Significant differences exist in the climate comfort ranges for tourists from different climatic regions when engaging in hiking activities. Tourists in the mid-subtropics exhibit the highest tolerance for daily maximum temperatures during hiking, whereas those in arid and semiarid regions have a greater comfort threshold for average relative humidity compared to individuals in humid and subhumid regions. (3) Over the past decade, the southern subtropics experienced the highest number of days suitable for hiking among tourists, while the plateau climate zone recorded the fewest. The frequency of comfortable hiking days per year (CDY) increased for tourists in the north subtropics, mid-subtropics, southern subtropics, and plateau climate zones but declined for tourists in the mid-temperate and south temperate zones. (4) Looking ahead to the future, climate conditions conducive to hiking for tourists in different climate zones are generally trending towards deterioration. By the year 2080, both the mid-subtropics and south temperate zones are projected to have the fewest CDY. While the southern subtropics may still have the most CDY for tourists’ hiking, it is anticipated to experience the most rapid decrease.