Global warming and climate change are serious issues facing humanity at present and education needs to focus on including informed-decision in classroom practices. The conceptual framework used in this study has provided interconnections that influence beliefs and understandings in providing a knowledge base for making “informed-decision” among high school students. This study was conducted in three year 9 classes in two high schools in the UK and among 65 students. An inquiry intervention model was developed using the 5E instructional model (Engage, Explore, Explain, Elaborate, and Evaluate) to identify beliefs and understanding and to strengthen students’ knowledge base. This study used a design-based research setting and utilised a mixed methodology. The Wilcoxon signed-rank tests were computed to examine the pre-post-difference among questionnaire items, and structural equation modelling (SEM) was utilised to explore the relationship between belief, understanding, and intention. Data analysis of the intervention revealed that students developed a strong understanding of the causes and effects of global warming. There is evidence that students used that knowledge to “inform-decision” in relation to global warming and climate change. Promoting informed decision-making through science teaching can encourage responsible action in the future. The real gap identified in this study is that the regular school curriculum does not engage socio-scientific issues in the real world and has no opportunity to organise an inquiry-based instructional sequence for informed decision-making
