As the 'next generation' guardians of the environment, there appears to be limited inquiry into young Canadians' environmental concerns. At the same time, online social networking is a predominant method of communication among young adults. This research explored online conversations regarding environmental concerns among young Canadian adults targeting the university student population. A qualitative content analysis was conducted using posted conversations from the online social media network Facebook. Conversations addressing environmental issues were summarized into four major themes. The first theme, 'Built Environment' (127 postings) centred on housing and transportation. The second theme, 'Natural Environment' (55 postings) accounted for issues of air quality, pollution and water quality. The third theme, 'Environmental Restoration' (52 postings) highlighted young Canadian adults' plans for environmental recovery. The fourth theme, 'Engagement and Activism' (31 postings) underscored students' use of the online social networking site for environmental advocacy. Young adults appeared to be environmentally conscious and, through the use of social networking, exchanged knowledge and opinions, and advocated for environmental change. Online social networking sites, such as Facebook, can serve as a communication channel that facilitates health information sharing and more importantly cultivates community capacity focused on environmental health promotion among young adult users.