While initial research on climate change communication focused on traditional media, such as news coverage of climate change and pro-environmental campaigns, scholars are increasingly focusing on the role of social media platforms, such as Facebook, Twitter, YouTube, and Sina Weibo. Social media platforms provide a space for three important domains of climate change communication: information, discussion, and mobilization. First, social media platforms have been used by scientists, activists, journalists, and ordinary people to share and receive reports about climate change. Policymakers and academics also use social media for climate change research. Second, social media platforms provide users with a space to discuss climate change issues. Scientists and journalists use social media to interact with the public, who also use social media to criticize policies, as well as media coverage. Finally, social media platforms have been used to coordinate rescue and relief operations in the aftermath of climate change–related disasters, as well as to organize movements and campaigns about climate change. However, most research about climate change communication in social media spaces are based on quantitative analysis of tweets from Western countries. While this body of work has been illuminating, our understanding of social media’s increasingly important role in climate change communication will benefit from a more holistic research approach that explores social media use in climate change communication across a variety of platforms, cultures, and media systems.