Scientific networks on Twitter: Analyzing scientists’ interactions in the climate change debate (2019)

Scientific issues requiring urgent societal actions—such as climate change—have increased the need for communication and interaction between scientists and other societal actors. Social media platforms facilitate such exchanges. This study investigates who scientists interact with on Twitter, and whether their communication differs when engaging with actors beyond the scientific community. We focus on the climate change debate on Twitter and combine network analysis with automated content analysis. The results show that scientists interact most intensively with their peers, but also communication beyond the scientific community is important. The findings suggest that scientists adjust their communication style to their audience: They use more neutral language when communicating with other scientists, and more words expressing negative emotions when communicating with journalists, civil society, and politicians. Likewise, they stress certainty more when communicating with politicians, indicating that scientists use language strategically when communicating beyond the scientific community.

Walter, Stefanie; Lörcher, Ines; Brüggemann, Michael (2019): Scientific networks on Twitter: Analyzing scientists’ interactions in the climate change debate. In Public Understanding of Science, 696-712. Available online at

Klimapolitik in den Medien – Das Publikum erwartet mehr. Befunde einer Befragung zu den UN-Klimagipfeln 2015 und 2018 (2019)


In einer Rezipientenbefragung wurden die Nutzung und
Bewertung der Berichterstattung zu den UN-Klimagipfeln 2015
und 2018 verglichen. Das öffentlich-rechtliche Fernsehen ist die wichtigste Quelle, um etwas über den Klimawandel zu erfahren, gefolgt von Privatsendern, Radio und Onlinemedien. Ein Großteil der Befragten hält die Berichte in den Medien für verständlich, wünscht sich aber eine ausführlichere Berichterstattung. Auch die Bedeutung der Anschlusskommunikation hat im Vergleich der beiden Jahre zugenommen. Immer mehr Menschen sprechen mit Freunden und Familie über den Klimawandel.

De Silva-Schmidt, Fenja; Brüggemann, Michael (2019): Klimapolitik in den Medien – Das Publikum erwartet mehr. Befunde einer Befragung zu den UN-Klimagipfeln 2015 und 2018. In Media Perspektiven (3), pp. 107–113. Available online at

Sechs Thesen für eine konstruktive Klima-Kommunikation (2018)


Trotz unseres umfassenden Wissens zum Klimawandel ist kein Rückgang der Kohlendioxid-Emissionen zu beobachten. Sechs Empfehlungen, wie eine bessere Klima-Kommunikation mehr Menschen in ihrem Alltag erreicht und den Klimaschutz voranbringt, hat Experte Michael Brüggemann formuliert.

Brüggemann, Michael (2018): Sechs Thesen für eine konstruktive Klima-Kommunikation. Available online at

Defragmenting News Framing Research: Reconciling Generic and Issue-Specific Frames (2018)


In our view, the best way to defragment news framing analysis is to synthesize related ideas and framing concepts and theorize the relationships between these concepts rather than aim for a unified conceptual definition (or none at all) or a single set of measurements. We focus here on one particular distinction, between generic and issue- specific frames (de Vreese, 2005), and hold that they should not be viewed as two alternative conceptualizations of frames but as complementary layers of framing that are situated on different levels of abstraction. The thesis of our chapter is that both of these types of frames are useful, and that a comprehensive understanding of the dynamics of public debates can be gained by combining the analysis of issue- specific and generic frames. This would be one important step toward defragmenting news framing analysis. We bolster this thesis by looking at a small but growing literature that examines what we call “hybrid frames” in news stories. We argue that frames in texts, more often than not, reflect both generic and issue- specific framing practices. Identifying the hybrid nature of these frames is a challenge that is not sufficiently tackled by current research.

Brüggemann, Michael; D’Angelo, Paul (2018): Defragmenting News Framing Research: Reconciling Generic and Issue-Specific Frames. In Paul D’Angelo (Ed.): Doing news framing analysis II. Empirical and theoretical perspectives. New York, NY: Routledge. Available online at

Echo Chambers of Denial: Explaining user comments on climate change (2018)


Although there is a broad consensus among scientists and journalists about the existence of anthropogenic climate change as a global problem, some segments of the population remain doubtful about the human impact on it. The internet provides citizens with opportunities to publicly voice their doubts and user comment sections of online media are popular form of user-generated content. This study identifies factors that foster comments that are sceptical or supportive of basic assumptions of anthropogenic climate change, drawing on online news in the US, the UK, Germany, India, and Switzerland. The results show that users adapt to the dominant opinion within the respective media outlet: user comment sections serve as echo chambers rather than as corrective mechanisms. Climate change denial is more visible in user comment sections in countries where the climate change debate reflects the scientific consensus on climate change and user comments create niches of denial.

Walter, Stefanie; Brüggemann, Michael; Engesser, Sven (2017): Echo Chambers of Denial. Explaining User Comments on Climate Change. In Environmental Communication: A Journal of Nature and Culture 12 (2), pp. 204–217. Available online at

From “Knowledge Brokers” to Opinion Makers: How Physical Presence Affected Scientists’ Twitter Use During the COP21 Climate Change Conference (2018)


Professional norms of science have played an important role in discouraging scientists from raising their voices in public. However, they are increasingly using social media to discuss and publicize their research. This study investigates the 2015 United Nations Climate Change Conference summit and examines scientists’ social media use by analyzing “digital traces” that scientists left on social media during the summit. Using geolocated tweets, we compare the Twitter use of scientists who attended the conference with those who did not. Combining automated, quantitative, and qualitative content analysis, the study shows how scientists participating in the conference provided live reporting and formed a transnational network. Scientists at the conference and elsewhere engaged in political advocacy, indicating a shift toward a new pattern of hybrid science communication, which includes characteristics that have formerly been attributed to journalism and advocacy.

Walter, Stefanie; De Silva-Schmidt, Fenja; Brüggemann, Michael (2017): From “Knowledge Brokers” to Opinion Makers. How Physical Presence Affected Scientists’ Twitter Use During the COP21 Climate Change Conference. In International Journal of Communication 12, pp. 1–22. Available online at

Opportunity makes opinion leaders: Analyzing the role of first-hand information in opinion leadership in social media networks (2018)


Theorizing information flows is at the heart of traditional communication theories such as the two-step flow of communication and the concept of opinion leadership. Social media have fundamentally altered how information reaches people. This study examines opinion leadership in social media networks and argues that opinion leaders may no longer need to rely on information provided by the media if they have access to first-hand information. To test this assumption empirically, we used data from the 2015 United Nations Climate Change Conference (COP21). Attendees of the conference had direct information about what was happening, which they were able to share live with their followers via social media. We used geo-located tweets to identify Twitter users who attended the COP21 summit. We then located these users in a data set of tweets that were collected based on the main conference hashtag (#COP21) and represent the wider social media debate on the conference. Our results, which are based on network analysis measures and Twitter user data, show that COP21 participants were more central actors compared to the average user in the network, and that they were more likely to have brokering positions. They were also more involved in the debate and received more attention from other users. We used automated content analysis to divide COP21 participants into different actor types and performed the analysis by actor group. The results show only minor differences across the actors and support the robustness of our analysis.

Walter, Stefanie; Brüggemann, Michael (2018): Opportunity makes opinion leaders. Analyzing the role of first-hand information in opinion leadership in social media networks. In Information, Communication & Society, pp. 1–21. Available online at

Die Medien und die Klimalüge. Falsche Skepsis und echte Leugnung (2017)


In diesem Beitrag geht es nicht um den anthropogenen Klimawandel, wie ihn die Klimawissenschaften definieren. Thema ist also nicht der langfristige Erwärmungsprozess der Erde, den die Menschheit durch die Emission von Kohlendioxid und den anderen klimawirksamen Gasen antreibt. Der Grundkonsens der Wissenschaft über diese Annahmen ist zum Beispiel in den Berichten der Weltklimarats (Intergovernmental Panel on Climate Change, IPCC, nachzulesen). Trotzdem, und darum geht es hier, gibt es eine öffentliche Debatte, in der die Existenz des anthropogenen Klimawandels heftig bestritten wird.

Brüggemann, Michael (2017): Die Medien und die Klimalüge. Falsche Skepsis und echte Leugnung. In Volker Lilienthal, Irene Neverla (Eds.): Lügenpresse. Anatomie eines Politischen Kampfbegriffs. Köln: KiWi, pp. 137–160.

Traditional and Shifting Roles of Science Journalists and Environmental Reporters Covering Climate Change (2017)


Climate journalism is a moving target. Driven by its changing technological and economic contexts, challenged by the complex subject matter of climate change, and immersed in a polarized and politicized debate, climate journalism has shifted and diversified in recent decades. These transformations hint at the emergence of a more interpretive, sometimes advocacy-oriented journalism that explores new roles beyond that of the detached conduit of elite voices. At the same time, different patterns of doing climate journalism have evolved, because climate journalists are not a homogeneous group. Among the diversity of journalists covering the issue, a small group of expert science and environmental reporters stand out as opinion leaders and sources for other journalists covering climate change only occasionally. The former group’s expertise and specialization allow them to develop a more investigative and critical attitude toward both the deniers of anthropogenic climate change and toward climate science.

Brüggemann, Michael (2017): Traditional and Shifting Roles of Science Journalists and Environmental Reporters Covering Climate Change. In Oxford Encyclopedia of Climate Change Communication. Available online at

Post-normal journalism: Climate journalism and its changing contribution to an unsustainable debate (2017)


Deliberative public sphere theories ascribe an ‘epistemic dimension’ to public debates: they do not necessarily foster consensus, but rather an enhanced understanding among the participants of the debate through the exchange of opinions backed by justifications (Habermas 2006; Peters 2005). Public discourses provide a critical validation of issues of shared relevance. They are an important precondition for the sustainable evolution of society as a society without open debates becomes blind to the concerns of its citizens. This is why the sustainability of public debates is a major concern for society and for communication studies. Reality will always fall short of normative models of the public sphere (see e.g. Walter 2015), yet when issues become so polarized that an open debate among speakers from different backgrounds becomes impossible, this constitutes a problem for democracy. In the following study of journalism’s role in the climate debate, I will argue that we are witnessing the evolution of post-normal journalism that is fundamentally interpretive and characterized by the blurring of institutional boundaries between journalism, science and advocacy.

Brüggemann, Michael (2017): Post-normal journalism: Climate journalism and its changing contribution to an unsustainable debate. In Peter Berglez, Ulrika Olausson, Mart Ots (Eds.): What is Sustainable Journalism? Integrating the Environmental, Social, and Economic Challenges of Journalism. New York: Peter Lang, pp. 57–73. Available online at