This study investigates how affective and self-related factors impact participation in science learning and environmental awareness and responsibility. Using PISA 2006 datasets from Taiwan and Canada having similar level of science competency, the model for this study verifies and expands an earlier model by examining the relationships among science-related interest, enjoyment, self-efficacy, self-concept, leisure time engagement, and future intended interest in science and how these relationships synergistically interact with environmental awareness and responsibility. The most consistent finding revealed that students' science self-concept in both groups was weakly associated with future intended interest and engagement in science learning and with their sense of environmental awareness and responsibility. Reasons for this phenomenon and possible causes underlying why students' science self-concept was weakly connected to their future intended interest in science learning are also presented. Finally, how the results of this study are important to science education instruction and research are forwarded in which students' identity and beliefs about self in science need to part of the next generation of science education reforms.