Science classrooms are uniquely positioned for teaching and learning about Earth's climate system and Global Climate Change (GCC), as well as how both are studied scientifically, particularly using technology-enabled modeling of big data. The Next Generation Science Standards underscore model-based and data-driven investigations of GCC, particularly at the secondary level. However, Earth science education is increasingly deemphasized in the K-12 curriculum, resulting in limited opportunities for teaching and learning about the Earth's climate system and GCC. To address this need, we have engaged in a long-term, NSF-funded project to investigate classroom use of Easy Global Climate Modeling (EzGCM), a web-based climate modeling suite designed for non-scientists using authentic NASA global climate data, which gives students opportunities to use EzGCM for engaging in scientific practices of climate science. This mixed-methods study is focused on the implementation of the curriculum module by two teachers in ten 9th-grade classrooms at one secondary school in a partner school district. We collected a diverse set of data in these classrooms, including: i) a pre- and post- assessment of students' content knowledge, ii) student interviews, and iii) students' module task artifacts. Quantitative analyses of student assessments of content knowledge, and qualitative analyses of students' interviews and tasks used helped explain students' performance and how EzGCM has supported students' conceptual and epistemic understanding of Earth's climate and GCC. The results show that students' conceptual understanding was similar across groups, and that it improved during the unit. Specifically, EzGCM helped students develop a more robust understanding of three primary climate-related themes: 1) temperature anomaly; 2) exponential growth; and 3) relationships between climate variables. While most students used the different visualizations available to support their claims, higher achieving students were able to more strongly link their evidence and claims to specific processes and products afforded by EzGCM.