Surface Downwelling Shortwave Radiation (rsds) and Surface Downwelling Longwave Radiation (rlds) are fundamental drivers of the surface energy balance and the broader hydrological cycle. Recognizing their pivotal role, this study investigates radiative forcing dynamics across the arid and semi-arid landscapes of Iran. The investigation is grounded in an analysis of data derived from the CMIP6. To mitigate structural uncertainties, a MMEM was constructed using five optimally selected models. Radiative projections were stratified across three futures (near, mid, and far) extending to 2100, utilizing Shared Socioeconomic Pathways SSP2-4.5 and SSP5-8.5 relative to a historical (1990–2014). Subsequent data analysis employed bilinear interpolation techniques alongside anomaly calculations. Findings indicate that during the historical period, radiative forcing variables exhibited an inverse gradient. In future epochs, rlds displays a consistent upward trajectory under both scenarios, driven by tropospheric warming and water vapor feedback mechanisms. Notably, under the SSP5-8.5 by the century’s end, southern coastal regions are projected to experience a substantial surge of 30 to 50 Wm^(-2). Conversely, rsds exhibits primarily diminishing or oscillatory behavior; nevertheless, positive anomalies were observed within the Central Plateau, a pattern attributed to the region’s inherent aridity. Consequently, the aggregate outcome of these shifts is the dominance of intensifying longwave radiation over variations in solar irradiance. The study demonstrates that this radiative imbalance precipitates a positive net energy balance and exacerbates evapotranspiration potential, posing a severe threat to Iran’s water resources. Furthermore, the analysis reveals that low-lying coastal zones exhibit the highest thermodynamic sensitivity, whereas the Zagros and Alborz highlands play a pivotal modulating role. generated here offer immediate, practical value for strategic infrastructure planning. Specifically, these findings can directly inform the site selection, expansion, and efficiency forecasting of solar power facilities, while providing a critical scientific foundation for overhauling climate-responsive design standards and optimizing building energy management protocols.