Global warming has fundamentally altered the statistical behavior of the Earth’s climate system, introducing non-stationarity across the atmosphere, oceans, and land. Variations in atmospheric circulation, such as shifts in monsoon systems, jet streams, and subtropical highs, have induced changes in oceanic dynamics, including sea surface temperature anomalies, altered circulation patterns, and marine heatwaves. These coupled atmospheric-oceanic processes, in turn, drive evolving hydroclimatic patterns on land, directly influencing precipitation regimes, streamflow variability, and the frequency and intensity of extreme events like floods, droughts, and compound extremes. This session aims to foster interdisciplinary discussion on detecting, modeling, and understanding non-stationarity across the interconnected Earth system. We invite contributions that assess or model non-stationarity in atmospheric, oceanic, or hydrological domains, along with its cascading impacts on hydroclimatic variability. We highly encourage research addressing individual and compound extremes, large-scale teleconnections, or regional climate responses. We also welcome submissions employing observational data analysis, climate and hydrological modeling, statistical and dynamical frameworks, and machine learning to explore how non-stationarity propagates across Earth system components. By integrating diverse perspectives from hydrology, atmospheric sciences, oceanography, and the broader geosciences, this session seeks to advance our understanding of evolving hydroclimatic extremes and support improved prediction, adaptation, and resilience strategies under a changing climate.