Coastal Wetland Conservation: Nature-Based Solutions to Mitigate the Impacts of Climate Change

Kristina Rodriguez

Coastal Wetland Conservation: Nature-Based Solutions to Mitigate the Impacts of Climate Change

Conserving tidal wetlands, such as mangroves and saltmarsh ecosystems, can mitigate the risks of coastal flooding and sea level rise associated with climate change. Nature- based solutions can benefit 40% of the world’s population that are exposed to sea level rise by mitigating storm surges and reducing the impact of waves and shoreline erosion. 

Coppenolle, Rebecca Van, and Stijn Temmerman. “Identifying Global Hotspots Where Coastal Wetland Conservation Can Contribute to Nature-Based Mitigation of Coastal Flood Risks.” Global and Planetary Change, Elsevier, 17 Jan.

The average density of the world’s coastal populations is expected to grow ten-fold by 2060. These low-lying coastal regions are exposed to the threats of climate change, including flooding, sea level rise, and strengthened storm intensity. Roughly 40 million people around the world are susceptible to coastal floods and could benefit from nature-based storm surge mitigation. The conservation and restoration of coastal wetland ecosystems, such as salt marshes and mangroves, is critical for supporting nature-based solutions that reduce the threats to flood-exposed coastal areas and populations. 

 

Coastal wetland ecosystems provide the natural capacity to mitigate threats associated with climate change. Mangrove forests and saltmarsh ecosystems are some of the most productive and biologically diverse ecosystems on the planet. Mangroves have the capacity to absorb up to four times more carbon dioxide by area than terrestrial forests. Alongside mangroves, the characteristics of saltmarshes provide a wide variety of goods and services that benefit humans, including weakening storm surge. Both coastal ecosystems play critical roles in supporting human livelihoods and food reliance. Conserving these coastal wetlands reduces the loss of property and vulnerability of coastal communities.  

 

Traditional coastal protection strategies, consisting of hard engineering infrastructure such as dams and seawalls, are insufficient to protect low-lying coastal areas from storm surge, floods, and erosion. These forms of grey infrastructure also have negative environmental and social impacts. For example, dams and seawalls have been shown to degrade natural ecosystems and accelerated erosion. It is also costly to maintain these structures in the face of projected climate and socio- economic changes. By comparison, restoring mangroves for coastal benefits is five times more cost-effective than grey infrastructure.  

 

A recent research article in Science Direct identifies global hotspots where coastal wetland conservation can mitigate coastal flood risks. Authors Rebecca Van Coppenolle and Stijn Temmerman from the University of Antwerp aim to simulate local analyses and widen the application of nature-based solutions on coastal ecosystems for climate change mitigation. The authors used a global GIS model to assess the storm surge mitigation of mangrove forests and salt marshes. The model pinpointed coastal areas with adjacent tidal wetlands that could protect the local population from storm surges. The results indicate that during a 100-year flood event, coastal plains benefit from storm surge mitigation. Moreover, the magnitude of the storm surge mitigation increases with the presence of tidal wetlands. The results of this study significantly advance the scientific understanding of the mechanisms that maximize nature-based mitigation provided by mangroves and salt marshes.  

 

Van Coppenolle and Temmerman’s study identifies numerous global hotspot regions where conservation of salt marshes and mangroves forests could help coastal communities adapt to the growing threats of climate change. Importantly, the study emphasizes how conserving, preserving, and restoring coastal ecosystems is a lost-cost, sustainable, and globally scalable alternative for mitigating coastal floods and erosion. Promoting the conservation of salt marsh habitats and mangrove ecosystems as a nature based solution would reduce storm surge, shoreline erosion and sea level rise to reduce the threats posed by climate change.   

 

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