This article assesses students' understanding of global climate change (GCC) and social factors affecting it. It was hypothesized that students who demonstrate pro-environmental attitudes are more likely to possess higher knowledge of GCC. It was further hypothesized that trust and personal efficiency would have a positive effect on the knowledge of GCC. To this end, 816 students of several universities in the Iranian Mazandaran province were randomly selected for a survey. Results show that the level of students' understanding of the GCC phenomenon is moderate and the social factors, environmental attitude, trust and personal efficiency have influence on their knowledge of GCC. Furthermore, the study shows that male students possess more knowledge of GCC than female ones.