With the rapid development of urbanization, greenhouse gas emissions increase. Vegetation transpiration (Ec) is a vital component of the water cycle. Understanding the response of Ec to greenhouse gas is critical for managing water resources under ongoing climate change. This study examines the spatial and temporal patterns of Ec across China from 2000 to 2023 and quantifies its relationships with three key GHGs: carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). We applied the Lee–Heghinian changepoint test to detect temporal inflection points, Pearson correlation analysis (PCA) to assess linear associations, and principal component analysis to identify dominant drivers. Spatially, Ec exhibited a clear southeast-to-northwest gradient, with the highest trend appearing in the humid southeastern and coastal regions and the lowest rates appearing in the arid northwest. Temporally, the turning point of the trend of Ec appeared at 2011. Ec increased significantly from 2000 to 2011 at 2.23 mm a−1, then declined from 2011 to 2023 at − 0.51 mm a−1. Our analysis reveals strong positive associations between Ec and CO2 (r = 0.87) and CH4 (r = 0.83), while the Ec–N2O relationship is moderate (r = 0.44). PCA confirmed CO2 was the primary contributor to Ec change, followed by CH4 and N2O. This suggests that greenhouse gases, particularly CO2, may play an important role in the variation of Ec. Our results could provide a theoretical basis for integrating greenhouse gas emissions considerations into vegetation water-cycle models and inform policy measures aimed at balancing carbon management.