Younger consumers are important in addressing environmental problems caused by consumption activities. It is mediated through green behavior, which is influenced by Internal factors. Thus, this study examines how young Indonesian consumers’ environmental attitudes, knowledge, and responsibility relate to their green consumption habits. Using the voluntary sampling approach, 328 respondents were chosen, and data were examined using SEM and descriptive analysis. The findings demonstrated that views about the environment and green consumer behavior were significantly influenced by environmental knowledge. A person’s attitude greatly influences their green consumption habits. These findings support the cognitive-affective-behavioral (CAB) hypothesis, which can be applied to similar study subjects or topics. An important factor influencing perceptions is environmental responsibility. It follows the Norm Activation Theory (NAM). In contrast to green consumption behavior, the effect of environmental responsibility was not significant. It is not in line with the NAM, so it is recommended that the theory be modified or other theories be used to examine similar variables. Environmental responsibility is significantly impacted by environmental knowledge. While attitudes were in the high category, knowledge, responsibility, and green consumption behavior were in the medium category. The study suggests marketers offer and promote eco-friendly products to provide more choices to consumers. These results also provide good insights for policymakers to achieve sustainable consumption targets by considering knowledge enhancement through environmental campaigns on social media.