LAUSR

Abstract This study focuses on students' interest in ecosystem services and sustainability to explain their awareness and optimism about the environmental issues of air pollution, water shortage and greenhouse gas emission in 50 countries around the world. We achieve this using the cross-sectional survey data of the 2015 OECD's Program for International Student Assessment (PISA), along with seemingly unrelated bi-variate weighted ordered probit modeling. We found that in addition to factors such as age, gender, immigration status, and economic, social and cultural status, interest in the biosphere is a significant determinant of students' environmental awareness and optimism. In fact, a level increase in students' interest in ecosystem services and sustainability is found to raise on average their awareness level by 15.3% for the issue of air pollution, 15.7% for the issue of water shortage, and 24.6% for the issue of greenhouse gas emission. Although students' interest in the biosphere seems to not have a significant effect on their expectations about the issue of greenhouse gas emission, it does however raise their level of optimism by 0.8% for the issue of air pollution, and 0.2% for the issue of water shortage. Furthermore, every level increase in students' environmental awareness is found to raise their optimism level by 17.3% for the issue of air pollution, 15.8% for the issue of water shortage, and 17.4% for the issue of greenhouse gas emission. Therefore, relying on the Theory of Planned Behavior (TPB), our results suggest that governments and policy makers around the world could successfully leverage the biospheric interests of their youth populations to successfully achieve their 2030 goals for sustainability.