其他摘要:Environmental issues are being discussed through social media with increased frequency. Researchers are starting to question whether social media demonstrates a green virtual sphere: a virtual public space to discuss environmental issues that is not governed by a single authority and that anyone can access. We investigate why people use Twitter to communicate about two Canadian-based environmental issues using interviews with 10 highly engaged users. We found that they used Twitter to access news and engage in debates; however, they also raised a number of concerns: the potential for overestimating the impact of their own and others’ online activities; the prospect of harassment from other users; and the possibility of being labelled an extremist. Given these findings, we conclude that in this case, Twitter only partially demonstrates the characteristics of a green virtual sphere because it increased access to information and provided a space for debate but access to the space was not equal and users were aware that discussions were likely being monitored.