<![CDATA[Global warming represents a critical environmental issue exacerbated by increasing greenhouse gas emissions, necessitating mitigation strategies that incorporate effective environmental education at the elementary school level. Although STEAM-based learning has demonstrated efficacy, further investigation is required into its practical implementation—such as through the construction of a mini greenhouse—to enhance students’ scientific thinking skills. This study seeks to describe the implementation of the STEAM approach integrated with the Project-Based Learning (PjBL) model in improving students’ scientific thinking skills. A descriptive qualitative method was employed. Data were collected through direct observation of students’ experimental activities, process documentation, and interviews designed to capture student understanding. The approach assessed students’ competencies in observation, inquiry, and inference during the construction of a mini greenhouse. The findings indicate that implementing STEAM through the five phases of PjBL significantly enhanced key indicators of scientific thinking, including observation, inference, prediction, and scientific communication. Students successfully drew connections between temperature phenomena observed in the mini greenhouse and global warming on Earth. Primary enabling factors included student enthusiasm and the accessibility of materials, whereas constraints involved limited time and inadequate measuring instruments. The implications of this study suggest that the STEAM approach aligns with the Independent Curriculum and reinforces the Pancasila Student Profile by cultivating critical, creative, and collaborative thinking. Future research should broaden the scope of subject areas and extend the observation period to evaluate the impact on environmental literacy more comprehensively.]]>
