Middle-school students are in formative stages for developing arguments on issues close to the heart and, as such, are well positioned to explore issues on sustainable living for articulating proposals to safeguard their environment. Science education for sustainable living requires students to scientifically investigate problems in order to gather evidence for proposing solutions for sustaining life. A four-step sequence was used with 14 preservice teachers and two classes of middle-school students for understanding sustainable living issues. Based on a range of sustainable living issues, the process included: (1) identifying the issue, (2) exploring associated concepts, (3) recording and articulating understandings, and (4) brainstorming realistic solutions and/or future projects. Two examples of how this process may work are provided (i.e., sustaining life on Mars, and chemical effects on water). These preservice teachers reflected on their practices and provided suggestions for improving pedagogy. It is argued that educators need to challenge pedagogical practices in order to develop critical thought for enhancing science education for sustainable living.