How relevant is climate change research for climate change policy? An empirical analysis based on Overton data

world’s land area, where 85% of the world population resides [10]. As such, it is unsurprising that the topic of climate change has become a hot topic in political and public debates and now features widely on political agendas across many different fields. In this study, we deal with the question of how research on climate change and policy are connected. According to Yin, Gao [11], the systematic understanding of the connection between science and policy is still limited, since reliable data are missing on a global scale. In 2019, however, the new Overton database of policy documents was released including links to research papers that are cited by policy documents. Yang, Huang [9] define policy documents in this context as “‘carriers’ of policies . . . [that] provide a channel through which policy sci- ence researchers can study the main contents of policies, policymaking processes and policy instruments”. Using Overton data, Yin, Gao [11] analyzed the connection between science and policy with respect to COVID-19. They found that “many policy documents in the COVID-19 pandemic substantially access recent, peer-reviewed, and high-impact science. And policy documents that cite science are especially highly cited within the policy domain. At the same time, there is a heterogeneity in the use of science across policy-making institutions. The tendency for policy documents to cite science appears mostly concentrated within inter- governmental organizations (IGOs), such as the World Health Organization (WHO), and

much less so in national governments, which consume science largely indirectly through the IGOs” (p. 128). Impact measurement of scientific papers on the policy area is part of a new branch in scien- tometrics: measurement of societal impact [12]. Whereas science impact measurements of papers were restricted to citation analyses (using Web of Science, WoS, or Scopus data) until recently, societal impact measurements are focused on impact analyses of papers on other parts of society than science [13]. One part of the society is of special interest in this respect: the policy area. The policy area is permanently required to find answers on certain societal demands (such as COVID-19 or climate change). Since science permanently produces research results that can (and should) be used in the response to these demands, it is interest- ing to know, whether and to what extent this happens. Fang, Dudek [14] defines the term ‘pol- icy impact’ in this respect as impact that “tells the story of how research outputs provide concrete evidence to support policy-making processes, which can be reflected by the references to research outputs in policy documents”. The use of research findings in the policy-making process is denoted as evidence-based policy-making [15] or science-based policy-making [16]. OPENing UP [17] regards “informing policy and influencing decisions . . . as one of the most notable effects of scientific research” (p. 24). Overview of studies on policy impact The overview of studies dealing with the use of scientific information/publications in policy

making by Vilkins and Grant [18] reveals that a number of studies exists that are based on interviews and surveys (with policymakers). These studies show, e.g., that the use of scientific publications in policy documents seems to depend on organizational culture and perspectives towards their use. Furthermore, some policy areas (such as information technology) use scien- tific information more frequently than others (e.g., immigration or justice). The use of scien- tific information in policy might be distinguished according to three stylized purposes: “‘instrumental’ use is direct and measurable for policy; ‘conceptual’ use . . . [is] indirect but rather affects thinking over a longer period of time; ‘symbolic’ use is when specific findings are selected for rhetorical or political argument” [18]. Sources of scientific information preferred by policymakers are the internet, meetings, and emailing colleagues. Yang, Huang [9] reviewed some studies that have analyzed networks of policymaking institutions to gain insights into PLOS ONE How relevant is climate change research for climate change policy? PLOS ONE | https://doi.org/10.1371/journal.pone.0274693 September 22, 2022 3 / 24