Nitrogen fertilization increases productivity in European grasslands but also drives N losses from soil through N2O emissions and N leaching. The European Union’s Farm to Fork (F2F) strategy aims to reduce fertilizer use and nutrient losses, though the impacts on future grassland productivity under climate change and elevated CO2 remain uncertain. This study evaluated the effects of the F2F strategy on yields, soil N2O emissions, and N leaching in temperate Alpine grasslands under current and projected global change conditions. The DayCent biogeochemical model was calibrated and evaluated using long-term datasets from permanent grassland sites in Western Europe. Calibration employed inverse modeling with the PEST optimization tool, followed by cross-evaluation. Future climate scenarios for 2041–2060 were generated using the LARS-WG stochastic weather generator under RCP 4.5 and RCP 8.5. Simulations considered baseline management and a F2F scenario with a 20% reduction in slurry-based N fertilization, while other management practices remained constant. Under current conditions, reducing N fertilization by 20% decreased yields by about 5%, while lowering soil N₂O emissions by ~15% and N leaching by 21%. Under future global change conditions, elevated CO2 is likely to compensate for yield reductions associated with reduced fertilization, resulting in yields comparable to or exceeding present-day levels at most sites. The mitigation effect of the F2F strategy on N losses persisted under future climates, with stronger reductions observed for N leaching than for soil N2O emissions. Yield-scaled losses decreased further, by up to 17% for soil N2O emissions and 42% for N leaching, though still falling short of the 50% target. The study demonstrates that moderate reductions in N inputs to soil can significantly decrease environmental N losses from grasslands without substantially compromising future yields under elevated CO2 conditions. However, achieving the F2F’s ambitious target regarding nutrient losses will likely require additional mitigation measures. The findings demonstrate that models can effectively assess how global change and mitigation measures jointly influence soil- and plant-related functions of grassland ecosystems, thereby supporting the evaluation of policy impacts.