This study examined a moderated mediation model with 254 Israeli junior high school students, hypothesizing that students' environmental hope would simultaneously mediate the relationship between their engagement in school-based environmental activities (green engagement) and their environmental behavior as well as their positivity ratio, but that students' self-control skills would moderate these mediation processes. The results showed that engagement was linked to self-reported pro-environmental behavior, as well as experiencing more positive than negative emotions. Multigroup structural equation modeling indicated that the model provided a good fit to the data, and rigorous bootstrap analysis confirmed the simultaneous mediating role of environmental hope--but only for students with high self-control skills. The limitations and implications of the findings are discussed, and future directions are presented.