“There are many uncertainties, but not knowing everything is not the same as knowing nothing”: A corpus-assisted discourse study of climate change uncertainty in online newsreader comments

Abstract

The scientific consensus is clear on the causes and consequences of anthropogenic climate change (ACC). Nonetheless, climate science involves some degree of uncertainty. Existing literature shows that such uncertainties are often exploited by climate sceptics, particularly in digital environments that favour polarisation and the spread of conspiracy theories (e.g., Climategate). At the same time, previous research has primarily focused on uncertainty as a rhetorical strategy exclusive to climate sceptics. As a result, a gap remains in understanding the nuances of how both sides of a polarised discourse engage with climate change uncertainty. This study seeks to address that gap by examining how individuals who are either supportive or sceptical of the basic assumptions of ACC appropriate uncertainty in their discourse. It also explores how these groups engage with sources, considering their role as an argumentative strategy. Adopting a Corpus-Assisted Discourse Studies (CADS) approach, this thesis analyses the Climate Crisis comment section of The Guardian’s website from January 2010 to December 2022. Online comment sections expose users to differing opinions and foster constructive interactions, offering a valuable space to examine the contested social representation of climate change. Findings reveal that amplifying uncertainty (e.g., references to “great uncertainty”) serves markedly different functions depending on the ideological stance of newsreaders and is not limited to sceptical newsreaders. These results should encourage the scientific community to engage more openly in the communication of uncertainties. Moreover, the most frequent cited sources are organisations, mainly the IPCC, academics, and news media, suggesting that traditional and credible sources remain influential in shaping the climate debate.