network, as shown in Figure 2b. As each of the three hashtags can almost represent one sub-theme of
the climate change topic and these three hashtags were tightly bundled might indicate an attempt by
#climatechange users to address all three communities together [91], consolidating climate change as
a topic rather than a loosely organized topic. Previous communication studies also conﬁrmed hashtags’
function of serving as a hybrid forum [ 68], where heterogeneous individuals coordinate to solve