Today's youth will inherit the brunt of climate change. Science literacy plays a critical role in raising future adults who commit to climate change mitigation by reducing daily household energy use. The objective of this study was to examine the mediating role of climate change knowledge efficacy on the positive influence of science literacy on engagement in energy conservation at home among Filipino adolescents. Data from the Program for International Student Assessment 2018 which included 7233 15-year-old high school students from 187 schools across 17 regions in the Philippines was used to address the study's objective. Results showed that climate change knowledge efficacy fully mediated the positive association between science literacy and household energy conservation among Filipino adolescents. The study discussed the importance of emphasizing environmentalism in science education, parenting, and community programs as a viable and long-term climate change mitigation response.