Increasing energy- and greenhouse gas-saving behaviors among adolescents: a school-based cluster-randomized controlled trial

Individual behavior change can serve as a key strategy for reducing energy use to mitigate greenhouse gas (GHG) emissions and improve energy security. A theory-based, school-based intervention to promote energy- and GHG-saving behaviors was developed by applying strategies and approaches from prior successful work in health behavior change. The focus was on changing behaviors rather than increasing knowledge, awareness, and attitudes, making extensive use of experimentally validated behavioral theory and principles. The intervention was evaluated in a cluster-randomized controlled trial. Public high school students (N?=?165) in a required course were randomized by teacher to receive a 5-week, five-lesson behavior change curriculum promoting changes to reduce home electricity-, transportation-, and food-related energy use and GHG emissions or their usual coursework. Students reported their energy- and GHG-saving behaviors at baseline and 6 weeks later (1 week after the completion of the curriculum for the treatment group students). Effects were tested with hierarchical linear models to account for potential clustering within classrooms. Students randomized to receive the curriculum statistically significantly increased their total energy- and GHG-saving behaviors compared to controls [adjusted difference?=?0.43 on a scale from 0 to 6 behavioral categories, 95 % confidence interval (CI)?=?0.07 to 0.80, p?=?0.02; number needed to treat (NNT)?=?4.1]. The largest effects occurred in hang drying clothing (adjusted difference?=?0.098, 95 % CI 0.028 to 0.165, NNT?=?4.1) and shutting off appliances and other energy-using devices when not in use (adjusted difference?=?0.095; 95 % CI 0.055 to 0.135; NNT 3.5). These results indicate that a theory-driven, school-based classroom intervention can increase energy- and GHG-saving behaviors among adolescents.