Climate change is projected to increase the risk of erosion and flooding driven by accelerating sea level rise, a changing wave climate and more intense or frequent storm events. In Australia, population growth is fastest at the coast, increasing the exposure of people to current and future coastal hazards.
Climate change and population growth are increasing the pressure for investment in coastal protection infrastructure.
Hard protection structures, such as seawalls, revetments and breakwaters have been a common solution to coastal hazard risk reduction. This has led to significant hardening of our coastlines with static structures that have little capacity to adapt to climate change, are expensive to build and maintain, and have serious social and environmental consequences as natural coastal ecosystems are replaced with artificial ones.
While hard structures will continue to have a place in coastal protection, more sustainable and climate-resilient approaches should be adopted into the future where appropriate.
Living shorelines have the potential to play important roles in climate adaptation and mitigation because of their ability to reduce the threats of coastal erosion and flooding and provide co-benefits such as carbon sequestration.
Living shorelines (or ‘nature-based methods/coastal defence’) are the creation or restoration of coastal habitats for hazard risk reduction.
This includes the rehabilitation of existing degraded habitats, restoration of those historically present, or the creation of new habitats in ecologically suitable areas. Typical habitats included in living shorelines are beaches and dunes, saltmarshes, mangroves, seagrasses and kelp forests, and coral and shellfish reefs. Living shorelines can restore coastal habitats alone (“soft” approach), or in combination with hard structures that support habitat establishment (“hybrid” approaches).
The key aim of living shorelines is to restore the ecological processes and functions that underpin the delivery of the natural coastal defence service.
Natural protection is provided by coastal habitats through wave attenuation, depth-induced wave breaking and sediment accumulation and stabilisation. Living shoreline structures can have benefits over traditional hard protection structures as they are a living, growing system with the potential to adapt to changes in climate and self-repair after storm events. A successful living shoreline project must create a self-sustaining ecosystem that can provide long-term hazard risk reduction.
For detailed information about living shorelines, see the Australian guide to nature-based methods for reducing risk from coastal hazards. To find out more about Living Shorelines Australia, continue reading here.
Cliff erosion in the Tiwi Islands, NT. © Theresa Konlechner
Rock fillets at Ballina, NSW. © Rebecca Morris