Plausibility is a central but under-examined topic in conceptual change research. Climate change is an important socio-scientific topic; however, many view human-induced climate change as implausible. When learning about climate change, students need to make plausibility judgments but they may not be sufficiently critical or reflective. The purpose of this study was to examine how students’ plausibility judgments and knowledge about human-induced climate change transform during instruction promoting critical evaluation. The results revealed that treatment group participants who engaged in critical evaluation experienced a significant shift in their plausibility judgments toward the scientifically accepted model of human-induced climate change. This shift was accompanied by significant conceptual change postinstruction that was maintained after a six-month delay. A comparison group who experienced a climate change activity that is part of their normal curriculum did not experience statistically significant changes.