Under current global warming and accelerated population growth scenarios, cropland irrigation water consumption has become a central issue limiting the sustainability of coupled human‐natural systems. This study proposes a new estimate of recent global cropland water consumption constrained by observations and provides attributions for its recent trend. By incorporating observations, including extracted cropland leaf area index and irrigation threshold data, this study provides improved estimates of recent global cropland evapotranspiration and transpiration as well as irrigation water consumption and withdrawal. The global annual consumption and withdrawal of irrigation water are estimated to be approximately 874 and 1,867 km³ (in 2005), respectively. From 2000 to 2014, a rapid increase in cropland irrigation was detected, especially in water‐deficient areas (i.e., hyperarid, arid, and semiarid regions). Climate change, which mainly consists of rising temperature and reduced moisture conditions, is usually distinguished as the major driving factor. Human‐induced increases in crop canopy cover have also contributed to more irrigation in hyperarid and arid regions. This study also provides suggestions for water‐savings‐targeted cropland management in water‐deficient areas based on the transpiration ratio (i.e., ratio of transpiration to evapotranspiration).

Land degradation poses significant threats to the sustainability of ecosystem structures, functions, and services, leading to increasing ecological risks. However, integrative assessment of the ecological risk driven by land degradation remains a challenge. In this study, we established a methodological framework for assessing regional ecological risk by integrating degenerative land use transitions with multiple ecological indicators. Specifically, 11 degradation modes of land use transitions and 7 indicators on ecosystem structures, functions, and services are quantitatively integrated using remote sensing data from 2000 to 2020 in the Qinghai-Tibet Plateau of China. Results revealed that the comprehensive ecological risk of the plateau is higher in the southern and northern regions. Furthermore, we found that land development from forests towards cropland and degradation towards grasslands lead to higher ecological risks than grassland development and degradation. The ecological risk tends to show a significant distance decay pattern around the patches with land degradation. Our research framework provides an efficient, explicit, and transferable means of exploring spatiotemporal changes in ecological risk caused by degenerative land use transitions at the regional scale. It presents a constructive tool for facilitating regional-scale land use and ecosystem management planning and assessment.

Terrestrial ecosystem water retention (TEWR) service is subject to climate change and elevated atmospheric carbon dioxide concentration (eCO₂), however, the relevant processes by which future climate change and eCO₂ affect TEWR are poorly understood. Here, we use the factorial simulation experiments from the Inter‐Sectoral Impact Model Intercomparison Project to address this research question. The experiments are based on three dynamic global vegetation models forced with the same climate change scenarios. Results suggest that compared to the preindustrial level, during 2070–2099, (a) TEWR change is highly uncertain, especially in the Southern Hemisphere. (b) Climate change will dominate the pattern of future TEWR change compared with eCO₂. (c) Precipitation and runoff change will dominate the future TEWR change in various regions, and the direct role of evapotranspiration (ET) on TEWR will be relatively small. (d) eCO₂ will mainly affect vegetation dynamics in energy‐limited regions to affect the runoff, and consequently affecting TEWR change. (e) eCO₂ will decrease ET and increase the runoff, resulting in a slight TWER change. These findings improve the understanding of the responses of TEWR to future climate change and eCO₂.