Despite characterized by large interannual variability (IAV), global terrestrial evapotranspiration (ET) has existed a consistent increasing trend since the 1980s. However, the regions and processes governing the present ET trend and IAV still remain unclear. Using an ensemble of process-based hydrological models, remote sensingbased, machine learning, and land surface products, we find that the increasing trend and substantial IAV in global land ET are driven by divergent regions. Result from models ensemble shows that the humid regions, especially in the Northern Hemisphere, contribute the 72.47 f 5.77 % of the increase in global land ET over 1982-2020. In this domain, climate warming and vegetation greening (increased leaf area index (LAI)) have caused the increase in ET of 0.43 f 0.22 and 0.30 f 0.13 mm yr-2, respectively, although the increased LAI is the largest contributions (63.69 f 25.13 %) to the global ET increases. Especially, climate warming in the humid regions at the high latitudes has prolonged the growing season, and provided sufficient water through freeze-thaw process for the enhanced plants photosynthesis in spring and even summer. The IAV of the global land ET, however, is dominated by drylands (with contribution fractions being 59.66 f 16.89 %), and dominant role in this region is mainly due to the fact that the precipitation, which serves as a primary source of moisture supply, has the large interannual oscillation with the El Nino/Southern Oscillation (ENSO) events and is largely allocated to evaporation. With future anthropogenic warming, global land ET is expected to continue rising with the trait of a significant interannual variations, and the dominant roles of humid regions and drylands still remains and are stronger than that in present. This study will merit more attention about regional roles for understanding and projecting dynamics of the global water cycle.