The Language of Uncertainty and Political Ideology of News Sources in Climate Communication

Communicating information about future events and outcomes is challenging when there is much uncertainty. This is evident in everyday discourse about climate change, including language in the popular media. What words are used to connote different degrees of certainty in varied news sources and how often do they occur? Different political ideologies vary when it comes to how they discuss issues around climate change. In this paper, we analyzed how progressive and conservative news sources express certainty when talking about climate change. We constructed a corpus of 18,906 news articles about climate change from 23 different news websites varying in political ideology. Our prediction was that if language use differs depending on the certainty represented for an issue, we should observe differences across news sources as a function of political ideology. The results show a bias in the expression of certainty, whereby progressive media show more certainty in linguistic form than do conservative media, providing insights into how language use reflects our underlying conceptual understanding of climate change. We discuss the implications of these results for conceptual models of language use and also applications to science communication.