There is robust evidence and medium agreement regarding the feasibility of coastal defence and hardening as adaptation options in some circumstances, which here includes grey coastal infrastructure. Economic and social factors may limit the feasibility of these options as they require large investments   . While these costs present challenges for rural areas, coastal defence structures may still be cost-effective in other areas, such as those with larger economies . Strong, transparent and inclusive governance is key, suggesting that these measures can occasionally fail to adequately balance competing stakeholder interests. Consequently, they may disproportionately benefit wealthier people and exacerbate existing vulnerability of the poor . They are also potentially maladaptive if they are not flexible or robust in response to a changing climate  and can have negative impacts on the local environment, habitats, ecosystem services, and communities .
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report