Learning from climate change news: Is the world on the same page?

augmented by COP3 (F1 0.46), since the crucial Kyoto Protocol (unfccc.int/kyoto_protocol) was signed during this edition. It is remarkable that when compared to the models for countries and political orientations, a greater share of the most informative features yielded by the COP model seems to be related to climate change. This contributes to answering the research question for this aspect (“What major topical and terminological differences can be found between COP meetings and how could they be explained?”). Some COP meetings stand out with many features related to climate change, while others fall short and show many other topics. It can well be that this is caused by the varying relevance of the meetings. Some meetings seemed to have little effect, while others were quite impactful, like COP15 due to Climategate (factcheck.org/2009/12/climategate/) and COP21 for the Paris Agreement (unfccc.int/process-and-meetings/the-paris-agreement/the- paris-agreement). There seem to be some clear differences between the early and more recent COP editions. Among other things, this seems to concentrate around the terminology used to refer to climate change—especially when it comes to urgency –, the attempts made to reduce the effect, and the output of the conferences itself. Examples are provided in terms of positive (in greenþ) and negative features (in red ) for the COP meetings that featured relevant phrases. Positive features are selected by the model as characteristic for that class, while the negative ones have been identified as uncharacteristic.

COP meetings are referred to by numbers in these examples. • Terminology When it comes to the terminology used to describe climate change, a threefold shift seems to have occurred. During COP3 in 1997, the term climate change was not indicative yet. This suggests that there were concerns, though no trend of change was being described yet. Instead, merely the emissions of carbon dioxide as well as the resulting greenhouse effect and global warming seem to have been the subjects of discussion, judging by the most informative features. This changed later, seeing that the term climate change was positively informative for COP15 in 2009. The terms global warming and greenhouse were no longer highly indicative for sub- sequent COP meetings 20 and 22 respectively. For COP25 (2019), yet a new level of terminology was observed. Here, the term climate change was no longer highly indicative. To the contrary, the terms climate crisis and climate emergency were. Similarly, global warming was no longer observed in the most informative features, but the more intense global heating was. It seems the urgency of the matter started to sink in at this point. 03: greenhouse+, global warming+, carbon dioxide+, emissions at levels+, climate change {, climate { 04: climate change {, carbon {, the crisis+ 15: emissions+, climate change+, environment { 20: global warming {, the climate {, crisis { 21: climate+, crisis {, climate crisis {, climate emergency {, planet+ 22: greenhouse { 23: carbon {, green {, warming { 25: climate crisis+, climate emergency+, climate change {,

tipping points+, global heating+, global warming {, greenhouse { • Conferences Related to conferences, several features stand out as well. During the earlier meetings COP3 PLOS ONE Learning from climate change news PLOS ONE | https://doi.org/10.1371/journal.pone.0297644 March 20, 2024 18 / 27