A groundbreaking study utilizing fuzzy-set Qualitative Comparative Analysis (fsQCA) has shed light on the complex conditions driving public contestation over 'hard' climate policies in OECD countries post-adoption. Analyzing 27 national policies implemented between 2009 and 2022, researchers found that perceived demandingness and unfairness, often coupled with socio-political polarization or low climate concern, are critical triggers for public backlash after policies are enacted. This ex-post analysis, drawing on 62 structured expert interviews and extensive secondary data, offers crucial insights for policymakers navigating the delicate balance between ambitious climate action and public acceptance.

The research addresses a significant gap in existing literature, which has largely focused on pre-adoption policy support or the political dynamics of policy formulation. It highlights a critical "principle-implementation gap," where initial public support for climate action can dissipate once the material and symbolic costs of specific policies become apparent. The study's methodology, fsQCA, allowed for the analysis of conditions in combination, revealing that contestation rarely stems from a single factor but rather from complex conjunctural causation.

Key findings indicate that policies perceived as highly demanding on target groups and simultaneously unfair in their distribution of costs are particularly vulnerable to contestation. This vulnerability is often exacerbated by a pre-existing environment of socio-political polarization, a general lack of public concern regarding climate change, or insufficient information provision surrounding the policy's rationale and impacts. The study emphasizes that these conditions interact, creating specific pathways to public opposition rather than operating in isolation.

Unlike much prior research that predominantly focused on carbon pricing mechanisms, this study broadened its scope to include other hard policy instruments such as regulations and technology phase-outs, providing a more comprehensive understanding of policy-specific dynamics. Furthermore, by including cases from the Global South within the OECD sample, the research modestly contributes to a more geographically diverse understanding of climate policy challenges. The findings underscore the imperative for policymakers to consider not just the technical efficacy of climate policies but also their perceived equity and the broader socio-political context in which they are implemented. Effective communication and transparent justification of policy impacts are paramount to fostering long-term public acceptance and ensuring the durability of climate action.