Recent Warming Amplification in the Yangtze River Basin Compared to the Global Land

Abstract Under global warming, regional warming amplification has drawn considerable attention. The Yangtze River Basin (YRB), one of the most densely populated regions worldwide, experienced frequent and exceptional warm extremes in recent decades, but whether the region is experiencing a warming amplification remains unclear. This study detects the signature of seasonal warming amplification by comparing warming magnitudes between the YRB, global land and the same latitudinal zone. Moreover, we use dominance analysis to quantify the relative importance of explanatory factors for seasonal surface air temperature (SAT) variability between periods. Results reveal a sharp acceleration in warming over the YRB in the recent three decades (1993–2023) compared to the preceding three decades (1961–1992), with rates during 1993–2023 exceeding three times those of 1961–1992. This shift marked a transition in dominant warming seasons from winter‐autumn (1961–1992) to spring‐summer (1993–2023). Spatially, seasonal warming magnitude over the YRB during 1993–2023 exceeds that of 37.56% (winter SAT) to 82.43% (summer SAT) of global land and 26.09% (winter SAT) to 74.38% (summer SAT) of the same latitudinal zone, with amplification most pronounced in spring and summer across the middle‐lower basin. Dominance analysis indicates that while intensified CO 2 forcing and rapid urbanization were major explanatory factors of warming over the basin, water vapor feedback (WVF) likely further amplified warming by enhancing longwave radiative processes. Our results highlight the important role of WVF as a nonlinear amplifier of recent warming over the YRB, with implications for understanding basin‐scale climate sensitivity and future heat risks.