This course aims to nurture critical thinking and to equip future generation of professionals with skills necessary for answering the grand call for forming collective actions towards sustainability. It introduces scientific, economic, social and political considerations in addressing sustainability challenges. Adopting a problem-driven and learning by doing approach, students will incorporate both scientific reasoning and deliberation in localized solution finding for a specific sustainability challenge faced by Hong Kong society. By taking the course, the students are prepared to discover and deliberate on value judgments integral to decision-making, to work with diversity, and to engage in debating contemporary sustainability issues from an informed and analytical perspective.