This mixed-methods study explored changes in preservice teachers' (PSTs) understanding of the nature of science (NOS) and their values as global citizens after a place-based intervention augmented with role-play activities concerning climate change. The study further probed how these values manifested during role-play improvisations, where participants adopted the roles of global citizens. Conducted in Turkey with 20 PSTs, it integrated local field trips and role-play scenarios focused on climate change. We led PSTs on excursions to locales such as hydroelectric power plants, enabling interactions with the environment and local individuals, and facilitating role-play on climate-related issues. Within these scenarios, we employed a contextualized NOS approach to foster a comprehensive grasp of the NOS. Data was collected using the 'Character and Values as Global Citizens Assessment' scale, interviews, and video-recorded role-plays. Results indicated that the place-based SSI intervention enhanced PSTs' perspectives on NOS and cultivated their global citizen values. The values demonstrated in role-play improvisations shifted based on the scenarios. Consequent to these findings, the study recommends purposefully designing role-play scenarios targeting specific value domains for enhancement. It recommends involving students in local issues and using NOS-enriched role-play scenarios to bolster their values, and NOS understanding and diversify their argumentative perspectives.