PLOS Climate PhD interview: Jessica Haak

Continuing our series of interviews with PhD students in climate research, PLOS Climate speaks to Jessica Haak, Research Associate and PhD candidate at the Chair of Comparative Political Science, University of Hamburg.

What did you study before your PhD, and why did you decide to go on to do a PhD?

Before starting my PhD, I completed a master’s degree in Empirical Democracy Research at Johannes Gutenberg University Mainz, Germany. During this time, I worked, among other topics, on empirical research on political attitudes and voting behavior. An initial idea for my master’s thesis was to investigate the contextual determinants of voting for Green parties. In exploring this topic, I noticed that objectively measured climate and weather extremes had received surprisingly little attention as a contextual factor in political science. This observation led me into the field of climate opinion research, where I encountered several open research questions that sparked my curiosity and that I wanted to pursue beyond my master’s studies.

My broader ambition to pursue a PhD developed gradually over the course of my studies. Each new methodological skill provided me with another tool to answer the questions that genuinely interested me. I found great motivation and enjoyment in working through complex problems and tackling methodological challenges. During my master’s program, I voiced my interest in pursuing a PhD for the first time and was fortunate to receive strong support from my then-mentor, who has since become a close collaborator. She invited me to work with her on a paper on dark social and citizens’ political self-perception, which also allowed me to attend my first academic conferences. Although academia presents many challenges, this period reinforced my passion for scientific research and confirmed my desire to continue a career in academia. This aspiration eventually brought me to the University of Hamburg, where I have been pursuing my PhD since June 2023. Here, I was able not only to significantly strengthen my research skills but also to gain valuable experience in teaching and academic service, including serving as a media editor for The Journal of Politics. These experiences have been highly enriching and have become an essential part of my professional development.

Could you tell us about your project? What are the key questions you’re hoping to address, and what methods/approaches are you using?

Anthropogenic climate change has increased the frequency, intensity, and severity of weather extremes such as floods, heatwaves, and storms. With each additional degree of warming, these events are projected to intensify further. As individuals experience such manifestations of global change firsthand, climate change becomes more tangible and transcends abstract statistics. My dissertation examines how exposure to weather and climate extremes shapes climate change opinion and related political behavior among both citizens and political elites. On the citizen side, one of my papers, recently published in Environmental Politics, investigates whether local temperature anomalies influence electoral support for the Green Party in Germany. By linking georeferenced survey data from 2017 to 2021 with temperature records, I analyze how both abnormally cold and abnormally warm temperatures affect intended and reported vote choice.

Because individuals’ motivations and ideological worldviews may influence how weather exposure translates into climate opinion, in a paper co-authored with Dennis Abel and Stefan Jünger, we examine how exposure to weather extremes interacts with political ideology to shape support for climate and energy policies. Focusing on Germany, where polarization over climate policy has grown over the past decade, we use a ten-wave georeferenced panel study with more than 5,400 respondents collected between 2014 and 2024 and link these data to high-resolution weather records. We evaluate how different types of weather extremes affect climate change policy support among right- and left-leaning individuals and explore potential mediators of this link. Overall, this part of my work seeks to clarify under which conditions and for whom weather extremes are influential in shaping climate policy preferences and related behavior.

In addition to citizens, I study how political elites respond to extreme weather. While research on public reactions is expanding, we know far less about whether and how politicians respond to climate change-related events. In a joint project with Sofia Morét and Lucas Schwarz, we investigate whether and how German Bundestag candidates adapt their climate communication on social media in response to local weather extremes. We argue that such events increase the salience of climate issues within constituencies, giving candidates strategic incentives to amplify their attention to climate issues. However, we expect heterogeneity in the intensity and stance of candidates’ responses along partisan lines. To test these expectations, we analyze more than 250,000 tweets from over 550 Bundestag candidates and members of the German Bundestag during 2021. We first use a stepwise zero-shot classification approach that leverages a large language model and a custom codebook to identify climate-related tweets and classify their stance toward climate action. We then link these data to weather extremes to assess whether candidates strategically leverage local weather extremes to advance their pro- or anti-climate agendas on social media.

In my dissertation, I will continue to develop additional projects that investigate how experiences with climate change shape political attitudes and behavior.

What excites you most about your project, and about the wider field?

What excites me most about my project is three aspects in particular: its interdisciplinarity, its methodological freedom, and its real-world implications. Studying how both citizens and political elites respond to weather extremes requires bridging social and natural dynamics. In practice, this means combining social science data with earth observational data, such as records from weather stations. Working across these domains pushes me beyond the traditional boundaries of political science and requires engaging with datasets and methods that are not typically part of the discipline. Although linking weather data to individual-level survey data is methodologically challenging, it has also been especially rewarding, as it has allowed me to work and meet with scholars from neighboring disciplines and develop expertise that would otherwise be difficult to acquire. More broadly, I value that my project is not tied to a single method or dataset. Rather than relying on a single approach, I draw on multiple types of methods and data, ranging from large-scale survey data to text data. For example, in our joint project on candidates’ climate communication on Twitter, we use large language models to automatically classify how politicians talk about climate change. This methodological diversity allows me to approach my research questions from different angles and to combine traditional political science tools with computational techniques.

Finally, the broader societal and political relevance of this research is a central source of motivation. Climate change is one of the most pressing challenges of our time. As William J. Ripple and colleagues (2017) emphasize in their article “World Scientists’ Warning to Humanity: A Second Notice”, signed by over 15,000 scientists, the window for meaningful action is rapidly closing: ”Soon it will be too late to shift course away from our failing trajectory, and time is running out. We must recognize, in our day-to-day lives and in our governing institutions, that Earth with all its life is our only home.” I am strongly motivated by this urgency and the broader question of how we can enable both political elites and citizens to support more ambitious climate policies. Implementing effective climate policy depends on both public support and responsive political leadership. By identifying the conditions under which citizens and political representatives become more attentive and supportive of climate action, I hope my work can play a small but meaningful role in advancing more effective climate policymaking.

Where you would like to take your career next?

At this stage, I still feel that there are many research questions I have only begun to explore. I remain deeply curious and motivated by the topics I work on, and I am eager to develop my current projects into larger research agendas. In particular, I would like to deepen my work on the interaction between political elites and citizens and better understand how their attitudes and behaviors influence one another in the context of climate change. At the same time, I genuinely enjoy the process of academic research itself, from working with data and problem-solving to collaborating with colleagues and developing new ideas. For these reasons, I hope to remain in academia. While I am aware that this may sound idealistic and that the academic system does not always make this path easy or secure, I am nevertheless determined to continue pursuing it. After completing my PhD, I plan to take on a postdoctoral position to strengthen my research profile, expand my methodological expertise, and keep asking questions!

What are your thoughts on the future of climate research? 

Climate research is a very broad field, which is why I will primarily focus on the literature on climate opinion in my answer. While this area is growing rapidly, there is still much work to be done. For example, much of the existing evidence on climate opinions originates from Western countries.We need more research from other parts of the world and, in particular, more comparative perspectives to assess how well existing findings travel across contexts. At the same time, there is considerable inconsistency in how climate opinion is measured, which makes systematic comparisons difficult. The same applies to the measurements of experiences with weather and climate extremes. Researchers often have substantial degrees of freedom in how they operationalize exposure to weather extremes. These choices can strongly shape results, yet they are not always transparent. I believe we need more open discussion of these methodological decisions and greater efforts to make such degrees of freedom transparent. More broadly, the field must develop a stronger shared language to integrate social and natural dynamics better. Without more systematic interdisciplinarity, generating the knowledge required to address the challenges of climate change in a timely manner will be difficult. At the same time, this work comes with an important responsibility: as researchers, we must communicate our findings clearly and accessibly beyond academia. As more people directly experience the manifestations of climate change, the demand for reliable, evidence-based information will only grow. If we fail to translate our results into language that is understandable and relevant to the broader public, we risk creating (even more) space for misinformation and misinterpretation. Effective communication is therefore not an optional add-on but fundamental to the future of climate research.