Projected sea-level rise and climate change mean low-lying coastal areas will become increasingly vulnerable to coastal flooding, storm surge and erosion (Wong et al., 2014). This will not only affect coastal communities but increase the exposure of assets, critical infrastructure and coastal industries, as well as cultural heritage and vital marine/coastal habitats which are likely to be lost through accelerated ‘coastal squeeze’. Globally, mean sea level rise is projected to be 0.28 to 0.98m by 2100 (but mean North Sea level rise could potentially be much larger, depending on the pace of ice mass-loss in Antarctica and Greenland), although exposure to coastal hazards will be exacerbated further by continued population growth, socio-economic development and urbanisation (Jongman et al., 2012).
Adaptation is essential. Diversified and holistic approaches are required to not only reduce the likelihood and magnitude of coastal hazards but also mitigate the consequences of these events when they occur, reduce societal vulnerability and enhance resilience. Adaptation strategies can be categorised according to protection, accommodation and retreat, and consist of a range of institutional, social, technological/engineered and ecosystem-based adaptation measures, as well as community-based adaptation (Wong et al., 2014).
In addition to strengthening existing lines of defence and investing in related infrastructure, alternative interventions may include working with natural processes (such as habitat creation/restoration of saltmarshes), combining with hard defences to create green-grey infrastructure, or establishing wider source-to-sea catchment-based management approaches to reduce the risk of estuarine/tidal flooding. Where it is no longer deemed sustainable to maintain existing defences, policy instruments will be required to roll-back or relocate communities, properties and critical infrastructure. Furthermore, policies must be in place to prevent inappropriate development in vulnerable coastal areas. Effective forecasting, warning and emergency management are also essential for enhancing preparedness, while recovery mechanisms can play an important role in promoting ‘resilient recovery’ (rather than a return to normal).
Therefore, the ‘coastal problem domain’ incorporates a multitude of policy areas and sectors which overlap the land-sea interface, including Flood and Coastal Erosion Risk Management (FCERM), civil contingencies management, terrestrial spatial planning, environmental conservation, water management and critical infrastructure, as well as aspects of marine management. This makes coastal adaptation highly complex.
