Community involvement in coastal infrastructure adaptation should balance necessary complexity and perceived effort.

Successful adaptation of coastal infrastructure requires public participation, and it is important to elicit accurate feedback from surveys and in-person interactions. But there remains a need for evidence about the efficacy of potential risk communication design metrics. This online experiment (n = 261) sought to understand the necessity of a multifaceted risk perception questionnaire to capture public input. Using six coastal infrastructure examples, risk perceptions were collected using a questionnaire highlighting multiple types of risk (intervention) or not (control). Public evaluations of risk did not differ in most cases. Moreover, the intervention imposed more cognitive strain on participants, which could unintentionally discourage public participation in the climate adaptation process. In this case, the single question provides the same input, with less effort. This finding is a reminder that effective risk communication for managing adaptation processes requires considering both the quality of public input and the effort required to provide it.