Mapping climate discourse to climate opinion: An approach for augmenting surveys with social media to enhance understandings of climate opinion in the United States

experience and scientific observation with the ultimate goal of fostering the development of a more progressive climate attitude. Both Environmental Justice and Grassroots Action have an intuitive relationship with CCO in that greater discussion of these topics in a region is associated with higher overall CCO (Fig 3b and 3c). We hypothesize the positive relationship stems from correlation between individu- als who actively monitor the local environment, protest threats to its integrity and individuals likely to respond positively to national surveys of climate opinions. This positive relationship between attributes of individual belief and twitter topic prevalence also occurs in individuals who feel personally responsible for driving change in their local community, which is the uni- fying theme of the Grassroots Action discussion. This topic largely focuses on people who pro- mote collective action by soliciting signatures for electronic petitions focused on climate action, and accordingly has a positive relationship with CCO. We find other counter-intuitive dependencies between topic and CCO. Increases in the Cli- mate Impacts category are associated with lower overall CCO. We initially hypothesized the opposite to be true as communities who are aware of and discuss the adverse impacts of cli- mate change are expected to take a progressive stance on the issue because they are directly experiencing its consequences. However, deeper analysis of the most common bigrams (pair of words which occur together) and most representative tweets from the Climate Impacts cate-

gory reveal that much of the discussion revolves around whether or not the currently observed impacts—sea level rise, drought, hurricanes, etc.—are a result of anthropogenic climate change or of a natural cycle. In this context, the inverse relationship between Climate Impacts and CCO is more intuitive. Higher levels of debate surrounding this topic indicate increased levels of uncertainty in the impacts of climate change, which is generally associated with communi- ties that hold a less progressive climate opinions. Regardless of the topic in question, a notable observation is that gaining insight into these regional results requires interpreting partial dependence plots, the topics that are present, and representative tweets. Conclusion In this study, we present a framework to augment survey data with social media data and apply it to the topic of climate change. Specifically, we use natural language processing to cre- ate county-level topic portfolios based on social media data. This is then used to develop regional predictive models which explore the relationship between Twitter topic discussion and climate change survey responses. This mapping between survey data and social media dis- course allows researchers to harness social media data to contextualize survey responses and better understand why people hold the opinions they do. The key finding from this study is that while the relationship between climate talk and cli- mate opinion can be intuitive, it often requires a deeper understanding of the context that

underlies the debate. There are many potential applications of these results and we believe one of the most promising uses of the insights generated by augmenting surveys with social media discourse is in the policy framing process. For example, should sustainability-motivated poli- cies such as carbon taxes be introduced at a national level, decision makers in the Pacific can leverage the regional attribute portfolio by presenting the tax as a program that would incen- tivize the development of clean energy. Policy makers in the Northeast, on the other hand, might choose to present the proposal as a method promoting environmental justice by ensur- ing that individuals and organizations are held accountable for the long-term impacts of fossil- based energy use. Framing policies in a way that aligns the pressing issues with the beliefs, atti- tudes and values of the constituents can accelerate the speed at which climate policies are PLOS ONE An approach for augmenting surveys with social media to understand climate opinion in the United States PLOS ONE | https://doi.org/10.1371/journal.pone.0245319 January 14, 2021 13 / 16