Visual Persuasion in a Transforming Europe

Climate change has been called the defining crisis of our time. In the last few years, millions of people have taken to the streets to demand urgent action on the escalating ecological emergency. Social media have had great importance in the development of the movement. For example, the virality of posts on Twitter and Instagram has quickly transformed the activist Greta Thunberg into an iconic figure, attracting supportive but also openly hostile reactions. The importance of images in the online communication of the movement and the emotions moving these activists and those who attack them online draw attention to the symbolic and emotional role of images for social movements. The PolarVis project will examine the role of visual content in processes of political polarization and belonging in the digital age by focusing on the intergenerational issue of climate change and the green transition. The visual dimension is increasingly salient online, where it underpins both conflict and connection. Photos, videos, and memes offer a powerful form of political communication. Political actors use them to frame issues, mobilize support an d build or undermine legitimacy, and citizens and platforms play a part by modifying, sharing, and amplifying them. This research project will forge a unique interdisciplinary framework to study the implications of networked visual persuasion on a large scale and to understand how, why, and with what consequences visual content becomes a mechanism of polarization and belonging in Europe. In particular, it will address four key questions: How do movements use visual content in their communication? What are the characteristics of this visual content, and how does it form visual narratives? How do online audiences react to the visual content? How does this content spread online and allow like-minded or opposed groups to emerge? By combining network analysis, computational text and image analysis, and in-depth qualitative approaches, the project will advance the study of polarization in its political, societal, and affective dimensions, illuminating dilemmas facing stakeholders that work to engage citizens with climate change issues online. Prof. Annie Waldherr (PI) and Dr. Nicola Righetti (Co-PI) lead the project at the University of Vienna which is part of a large international and interdisciplinary collaboration within the CHANSE initiative. Partners include the coordinator of the consortium Alexandra Segerberg (Uppsala University) as well as Luca Rossi (IT University of Copenhagen), Daniel Oross (Centre for Social Sciences, Hungarian Academy of Sciences), and Nicole Doerr (University of Copenhagen).

Social media has become a central battleground for climate change debates, but what drives people to share climate-related content? Our research reveals that it is not simply algorithms deciding what spreads online - emotions, identities, and communication choices of different political communities play a decisive role. One of our central findings concerns the power of visual content. Analyzing social media activity around the 2021 German federal election, we found that posts featuring images, videos, or visual links consistently attracted more engagement than text-only posts. But visuals alone do not tell the whole story: how people emotionally react to content matters just as much as what they see. Anger, in particular, is a strong driver of sharing behaviors - but not equally so across all political groups. Among supporters of right-wing populist parties such as the AfD, anger and outrage strongly fuel the sharing of climate-sceptic content. In contrast, within green communities, these same emotions tend to discourage sharing. This challenges a widespread assumption: that platforms inevitably fuel anger and division because their algorithms reward outrage. Our findings suggest a more nuanced picture. Yes, algorithms play a role - but the values, identities, and strategies of different communities shape what actually circulates. Different publics do not simply react to algorithms; they actively co-create the emotional landscape of online debate. Our research also introduces a new tool for measuring structural polarization on social media. Using network analysis, we developed a method that assigns individual accounts and communities a "polarization score", making it possible to quantify how divided online spaces really are - and whether that division is growing or shrinking over time. This matters because polarization is often discussed in vague terms; our approach makes it measurable and comparable across platforms and time periods. For journalists, policymakers, and civil society organizations, tools like this can provide concrete evidence. Finally, we examined climate content on TikTok - one of the fastest-growing platforms for political communication among younger generations. Analyzing videos from German-speaking climate activist accounts, we identified distinct visual content clusters, including protest footage, nature imagery, and political commentary, and measured whether different formats trigger more or less emotional conflict in comment sections. TikTok is increasingly where young people encounter and form opinions about climate change, making it essential to understand which content fosters constructive engagement versus inflaming division. Together, these findings carry practical implications. For communicators and policymakers working on climate issues, understanding which emotions drive engagement in which communities are essential for designing more effective, less polarizing public communication. The goal is not to avoid emotion - but to understand it well enough to foster more constructive conversations about one of the defining challenges of our time.