Using decision pathway surveys to inform climate engineering policy choices

Over the coming decades citizens living in North America and Europe will be asked about a variety of new technological and behavioral initiatives intended to mitigate the worst impacts of climate change. A common approach to public input has been surveys whereby respondents’ attitudes about climate change are explained by individuals’ demographic background, values, and beliefs. In parallel, recent deliberative research seeks to more fully address the complex value tradeoffs linked to novel technologies and difficult ethical questions that characterize leading climate mitigation alternatives. New methods such as decision pathway surveys may offer important insights for policy makers by capturing much of the depth and reasoning of small-group deliberations while meeting standard survey goals including large-sample stakeholder engagement. Pathway surveys also can help participants to deepen their factual knowledge base and arrive at a more complete understanding of their own values as they apply to proposed policy alternatives. The pathway results indicate more fully the conditional and context-specific nature of support for several “upstream” climate interventions, including solar radiation management techniques and carbon dioxide removal technologies.Governments worldwide are facing a host of public policy controversies that involve tough tradeoffs across economic, environmental, temporal, and social objectives. These choices typically involve multiple stakeholders and uncertainty as to the effectiveness of policy responses. Although the acceptance of policy initiatives is never guaranteed, more broadly supported options will emerge when the views of constituent stakeholders are understood in advance and when policy design anticipates and responds to the reasons behind public support or opposition.Nearly all experts agree that human-caused emissions of carbon dioxide (CO₂) and other greenhouse gases (GHGs) are already responsible for significant changes to the earth’s climate. These changes include higher mean temperatures, shifts in rainfall amounts and location, sea-level rise, and more frequent and severe droughts and storm events (1). However, policies aimed at mitigating the effects of climate change are controversial, in large part due to disagreements about the sources and extent of climate change or the perceived quality of the associated policy options (2). Recent reports of the Intergovernmental Panel on Climate Change (IPCC) thus call for further policy initiatives, wherein citizens will be asked about new technological and behavioral initiatives intended to mitigate the worst impacts of climate change.In such contexts, the responsibility of public officials is twofold: help citizens and other stakeholders become better informed about the nature and distribution of the risks and benefits of proposed actions, then find ways to listen to and act on their ideas. A fundamental challenge is to develop methodologies that accurately capture public input, including learning about how different groups within society think through or evaluate a range of policy options. Eliciting and understanding public opinion is challenging, however, because people use diverse mental models to interpret information and make sense of policy options (3). Peoples’ assessments of options are also filtered through what Kahneman (4) and others have referred to as “fast and slow” thinking. Fast and slow thinking includes a variety of cognitive processes that involve deliberative attention to problems as well as heuristics (or “rules of thumb”), which are efficient but can also be responsible for judgmental errors (e.g., anchoring on selected aspects of a problem).New, large-scale technologies that raise difficult ethical questions and involve uncertain outcomes significantly compound this challenge. A primary example is climate engineering technologies designed to capture and store CO₂ or to reflect sunlight away from the earth. Both have recently come under consideration due to rapid increases in global temperatures and increased concerns about the vulnerability of global ecosystems (5, 6).Carefully designed surveys will continue to play an important role in shaping public policies (7, 8). In the context of climate mitigation and adaptation actions, however, we question a primary dependence on conventional surveys. This concern arises because many climate mitigation options, such as large-scale geoengineering technologies, are unfamiliar and could represent an “unprecedented human intervention into nature’’ (9). In such situations, our worry is that some survey approaches may encourage quick responses that fail to incorporate key factual information and overly reflect the automatic choices and political ideologies characteristic of “fast” thinking, in contrast to slower and more deliberative thinking needed for unfamiliar, multidimensional decisions.In addition, survey research reveals two kinds of motivation that reduce the accuracy of participants responses: solution aversion, wherein people contest policies suggested by environmental scientists (10), and social desirability, wherein respondents edit reported behavior to avoid embarrassing themselves (11). Scholars of public participation are calling for new methods that increase response accuracy and can help to “open up” citizens’ analytic and participatory appraisal of new technologies and policies (12). A related trend in public participation is the adoption of more deliberative designs, endorsed in both the United States (13) and the United Kingdom (14), particularly because they are viewed as providing opportunities for discussion, reflection, and learning (15).This paper describes a “decision pathway” approach to surveys that addresses these challenges by combining the strengths of interactive deliberative designs with the larger and more representative sampling provided by surveys. We begin by reviewing the literature on public attitudes toward climate change, including recent shifts to consider climate change in reference to both in situ policy contexts (e.g., urban planning) and emerging mitigation or adaptation options (e.g., greater dependence on nuclear power). We follow with a discussion of the potential contribution of decision-making theory to design and implement deliberative surveys (14, 16). We then summarize empirical results from a climate-change pathway survey of a representative sample of US citizens (n = 800). To ensure informed responses and to address the technical and social complexity of required decisions, the survey design follows the lead of earlier “mental models” work (3) and incorporates tutorials on leading climate engineering techniques (e.g., carbon capture and storage, solar radiation) to encourage reflection on—and possibly changes to—participants’ values, reasoning strategies, and policy choices. We summarize these findings and their implications for the development of a broader methodological toolkit to aid decisions about novel and controversial technologies.