As a remedial measure to human-induced climate change, it is imperative to develop intrinsic altruistic values and adequate knowledge of environmental phenomena and behavior to act in favor of the environment. The study aims to assess the effect of an Environmental Education Program (EEP) based on empathy, reflective thinking, and information on preadolescents' environmental values and knowledge. For that, a non-equivalent control group design was used. Data collection was done through questionnaires, checklists, and participant thought diaries. Forty-six students (eleven-to-twelve-year-old children) selected through purposive sampling from the sixth standard of two semi-urban schools in Kerala, India, constituted the sample. In the intervention, empathy was manipulated through stories and empathy exercises, reflective thinking through thought diaries, and information on environmental phenomena, issues, and the effect of human actions through stories and knowledge exercises. Empathy, reflective thinking, and information manipulations positively influenced the participants' environmental values and knowledge, and the effect manifested in cognitive, affective, and conative dimensions. The study has implications for conducting Environmental Education indoors effectively by integrating affective, cognitive, and metacognitive approaches. Empathy stories can be utilized to address various environmental phenomena and issues. Reflective thinking on environmental phenomena and issues can be applied to teach appropriate environmental behaviors.