Intact coral reefs , seagrass meadows  and mangroves   provide a variety of ecosystem services that are key to island communities, including provisioning services , regulating services , cultural services  as well as supporting community resilience . If coastal ecosystems are degraded and lost, then the benefits they provide are also lost . In small islands where the risk of loss to ecosystem services is high , many of these ecosystem services cannot be easily replaced . The beneficial role that coral reefs play in coastal protection through wave attenuation, and therefore enhancing climate resilience in small islands, has been extensively studied . Indeed, it has been demonstrated that in small islands  averted damages as a result of protecting intact coral reefs can be considerable when expressed as a percentage of GDP . Ferrario et al.  conducted a global meta-analysis including many small islands across the Atlantic, Pacific and Indian oceans and found that coral reefs reduce wave height by an average of 84%  and that reef crests alone dissipate most of this energy. Based on another meta-analysis of 69 case studies worldwide , Narayan et al.  observed that coral reefs, mangroves and seagrass reduced wave height by 70%, 31% and 36%, respectively  and thus perform an essential role in protecting human lives and livelihoods . Post-TC studies have provided additional evidence for the protection services offered by coastal ecosystems. On some Caribbean islands  where the dense indigenous vegetation belt was preserved, the vegetative structure buffered the waves of TCs Irma and José , reducing the extent of marine inundation and shoreline retreat to a 30-m-wide coastal strip against values >160 m in deforested areas . By contrast, the destruction of mangrove ecosystems, even a few trees around the fringes, can accelerate coastal erosion, as exemplified by observations in Micronesia .
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report