Ideological biases in social sharing of online information about climate change

Terms such as decision and withdraw in each of the communities show that the Paris Agree- ment announcement is a major topic of conversation during this seven-day period, even span- ning the ideological/geographic divisions illustrated by Fig 6a. The left-wing communities are reasonably similar to each other, while the right-wing community is unique in its mention of previous US political figures such as Obama and Gore and use of scientific terminology. The bigrams mostly confirm the findings in Fig 6b, but also highlight differences in terminology, e.g. greater prominence of global warming in right-wing Community 2. Fig 6 and Table 2 dem- onstrate that there is variation in the geographic scope of the communities. The most apparent contrast exists between Community 1, which heavily features UK news sources, and Commu- nities 2 and 3, which include mostly US sources. The distribution of words and bigrams in Fig 6b and 6c show some topical differences between the four communities in the left-wing cluster. Communities 3 and 4 include more terms related to the consequences of the decision for the American people whereas Community 1 is mainly concerned with the international political Fig 6. Source domains and content of media articles shared within the five largest communities in the information-sharing network. Tokens in each plot are weighted (using TF-IDF) to make distinctive tokens prominent. Circle size is scaled to indicate the total number of

URL shares within the community. Terms coloured black are the highest weighted terms required to reach 15% of the total weight in a community. For visual clarity, each stemmed token is represented by the most common token that maps to it (or pair of tokens for bigrams). https://doi.org/10.1371/journal.pone.0250656.g006 PLOS ONE Ideological biases in social sharing of online information about climate change PLOS ONE | https://doi.org/10.1371/journal.pone.0250656 April 23, 2021 15 / 25