„The Flooding Makes it Clear That the Climate Crisis is Already Here”: The Impact of Weather Extremes on Candidates' Climate Communication on Twitter

How does exposure to weather extremes and anomalies influence the behavior of political elites? Although previous studies have shown that extreme weather can heighten public concern about climate change and increase the importance of climate issues in voters' minds, little is known about how political elites respond to the impacts of climate change. In this study, we examine whether and how German Bundestag candidates adjust their climate change communication on social media in response to local weather extremes. We argue that candidates have strategic incentives to amplify their attention to climate issues following such events, as weather extremes are locally confined and can increase the salience of climate issues within their constituencies. However, we expect heterogeneity in the intensity and stance of candidates' responses along partisan lines. Social media platforms, particularly Twitter, are crucial in this context, as they provide candidates with a direct channel to react to unfolding weather extremes in real-time and to circumvent the delays typical of traditional media. Our analysis draws on over 250,000 tweets from more than 550 candidates and members of the German Bundestag throughout 2021. In the first step, we employ a novel stepwise zero-shot classification approach that leverages a large language model (LLM) and a custom codebook to identify climate-related tweets and classify their stance toward climate action. In the second step, we link the Twitter data with georeferenced weather records. Thus, we can assess whether candidates strategically leverage local weather extremes and anomalies to advance their (anti-)climate agendas on social media.