To be speciﬁc, although “ipcc”, “cop”, and “un” were mentioned in both discourses (yellow
in Figures 3 and 4) in earlier years, the clusters to which they belonged had signiﬁcantly di ﬀerent
meanings. As mentioned in the results section, these hashtags were associated with a series of scientiﬁc
hashtags in the climate change discourse, appealing to global eﬀorts. In the global warming discourse,
they were clustered with “hoax” and “frame”, showing lack of belief in climate issue facts and hesitation
about global e ﬀorts. More recently, when discussions about temperature, politics, and hesitation
signiﬁcantly shrank in the global warming discourse, the wo discourses showed more similarities about
the importance of scientiﬁc concepts according to Figure 5a,b. However, links between global eﬀorts
and scientiﬁc facts were not constructed in the global warming discourse. According to a network
model for cognition, the lack of associations means fewer psychological activations will spread to