Giving up land? Explaining planned retreat in times of climate change

Transformational adaptation to climate change becomes increasingly urgent. Experiencing a severe hazard event is insufficient to enable a transformational response. Yet, there is no solid theoretical or empirical evidence on what policy and other social explanations enable transformational adaptation to climate-induced hazards. Our article addresses this gap by critically examining empirical evidence on theory-grounded explanations for transformational responses to the most costly and devastating climate-induced hazard: flooding. After systematically collecting empirical research, we compare transformational responses to floods, focuzing specifically on managed retreat and planned relocation. Our analysis combines qualitative data analysis and network analysis and covers 54 articles describing over 105 cases in more than 31 countries worldwide. By differentiating levels of change, we find that transformational adaptation is reported in the literature as occurring via various types of policy change: from incremental steps to a paradigm shift. Most studies pay attention to shocks like floods that trigger transformational adaptations (45 out of 54 articles). Notably, specific combinations of social explanations are reported to enable transformations as a series of steps (i.e. economic/financial and socio-behavioral factors facilitate first-order policy changes), complemented by changes in the legal system (for second-order policy changes). Empirical evidence confirms that the paradigmatic third-order policy change additionally necessitates policy entrepreneurs and advocacy coalitions. Our analysis calls for interdisciplinary efforts to link case-study insights with theoretically embedded explanations from policy and legal studies, and the economic and socio-behavioral domain to systematically reveal generic combinations of explanations that enable transformational adaptation.Transformational climate change adaptation (TCCA) could be realized via incremental steps, from a change of policy instruments, and via a paradigm shift that transforms place-based human ecosystems.For incremental change, behavioral and economic explanations are especially important but are either underexplored or not specified in empirical literature.Besides shocks, the most reported policy-change explanations for TCCA are policy entrepreneurship, advocacy coalitions and framing.As climate-related hazards intensify, policymakers might anticipate these windows of opportunity for policy changes to mobilize transformations.Besides policy change scholarship, other social science theories are needed to account for financial/economic and behavioral drivers explaining TCCA.