Nudging by design: calibrating climate and health interventions.

Introduction: Climate and health challenges increasingly require behaviorally informed approaches that complement structural policy tools. Nudging-changes in choice architecture designed to pull or push people in certain directions-has become widely used across climate and public health domains. However, its application varies considerably in both intensity and disciplinary orientation. Key findings: This article introduces the Nudge Intensity Model, a conceptual framework that positions nudges along a continuum from soft to moderate to hard interventions. Drawing on insights from communication, social and environmental psychology, design, policy studies, and economics, the model clarifies how different forms of nudging exert varying degrees of behavioral influence and how they can be calibrated to context, ethical considerations, and policy goals. Illustrative examples from climate and health interventions demonstrate the need for more deliberate calibration. Conclusion: The model aims to support practitioners in designing context-sensitive, legitimate, and effective behavioral interventions.