This study presents a hybrid methodology for planning green spaces to enhance urban sustainability and livability, evaluating the impacts of climate change on cities. Cities, once accommodating a small population, have become major centers of migration and development since the eighteenth century. Rapid urban growth intensifies infrastructure, environmental, and social challenges. Fossil fuel reliance and deforestation increase greenhouse gas emissions, exacerbating climate change, impacting ecosystems, and urban livability. This research assesses green spaces in Izmir's Bayraklı district by assigning weights to site selection criteria via the analytic hierarchy process (AHP), entropy weight method (EWM), and Game Theory. The weighted linear combination (WLC) method integrates these weights to produce decision maps. Game Theory harmonizes discrepancies between AHP and EWM, influencing the decision maps. Notably, incorporating climate change criteria reduced highly suitable areas from 50.3 to 41.5%, stressing climate considerations in planning. Grey relational analysis (GRA) prioritizes investment areas, showing objective, criterion-based planning's importance in sustainable urban development.