Socio-semantic configuration of an online conversation space: The case of Twitter users discussing the #IPCC reports

In public debates, climate change communication tends to polarize into communities for and against the scientific basis of global warming. We analyze mention networks on Twitter around the publication of the Fifth Assessment Report (AR5) of the Inter-governmental Panel on Climate Change (IPCC) Working Group 2 and 3 reports that were published in March–April 2014. Building upon earlier research into climate skepticism and polarization of climate change debate, we focus on the relative prominence of different types of Twitter user accounts, in terms of engagement with other users and their alignments towards the scientific basis of climate change. We distinguish a “heart” actively discussing IPCC from a “shadow”, which more anecdotally mentions IPCC and is likely to correspond to the remainder of a public space minimally interested in IPCC-related reports. We develop an original network analysis framework that enables us to analyze and deconstruct the inner structure of this heart’s strongly intertwined engagement dynamics. Interesting observations relate to the position of critical users, who are in the minority, but are in relative terms most engaged with and most engaging with other users in this arena, while the media, casual users and governmental agencies occupy relatively less prominent positions. We further qualify the various structural positions by demonstrating that they correspond to different types of vocabulary specific to user types and positions. This socio-semantic approach may be generally helpful to disentangle semantic and structural polarization in online conversation spaces where opposing poles precisely appear to be mixing.