How mangroves can help build resilience to coastal flooding

According to UNESCO: “These extraordinary ecosystems contribute to the wellbeing, food security, and protection of coastal communities worldwide. They support a rich biodiversity and provide a valuable nursery habitat for fish and crustaceans. Mangroves also function as a form of natural coastal defense against storm surges, tsunamis, rising sea levels and erosion. Their soils are highly effective carbon sinks, sequestering vast amounts of carbon.”

A paper published in Nature estimates 46% of global assets are at risk of flooding by 2100, making the cost of inaction $14.2 trillion worldwide – one-fifth of global GDP. With so much on the line, flood defenses, such as mangroves, could become essential for enabling organizations to adapt with climate change. The problem is that mangroves are rapidly vanishing. In fact, UNESCO says up to five times faster than overall global forest losses and recent projections illustrate that the amount of mangrove coverage has been halved in the last 40 years.

Previous research by Cervest’s Earth Scientist, Dr. Edward P. Morris - Cutting the costs of coastal protection by integrating vegetation in flood defences - highlights how coastal flooding is increasing due to the expanding population and links this back to the loss of ecosystems. It is estimated that around 600 million people are at risk of coastal flooding, of which 320 million are in urban areas.

Studies have shown that ecosystems play an integral part in reducing this type of flooding. For example, a study published by the University of California, in the journal Ecosystem Services, Return on investment for mangrove and reef flood protection, also uncovers how mangroves and coral reefs offer protection from coastal floods. Further to this, researchers found there were cost-effective, accessible, mangrove preservation methods in 20 countries.

Mangroves are just one example of where organizations can reduce costs by including nature-based solutions in both their adaptation and mitigation strategies. Singapore’s Green Plan, which includes planting a further one million trees across the city-state by 2030, is a good example of this in action.

“Could mangroves help save the world?” A BBC article covered just how important they are when protecting our planet from various threats. This includes fighting against climate change, shielding coastlines, and supporting communities.

Morris’s research includes evaluating the use of coastal vegetation including mangroves, marshes and fronting levees for reducing global coastal protection costs. His research covers the topic of mangrove conservation, and it focuses on the use of vegetation for cost-saving, sustainable coastal protection.

The results were clear: “We show that incorporating vegetation in hybrid coastal protection results in more sustainable and financially attractive coastal protection strategies. If vegetated foreshore levee systems were established along populated coastlines susceptible to flooding, the required levee crest height could be considerably reduced.” That’s why it’s vital to conserve mangrove ecosystems today.

With 46% of global assets at risk from flooding, organizations first need to identify whether their assets are among those at risk before employing coastal protection. However, conducting this analysis in-house can be both costly and time-consuming. Multiple factors go into understanding coastal flood risk in the context of climate change, such as the expansion of sea level as the ocean warms and the contributions from melting ice caps and glaciers.

Leveraging the power of climate intelligence, our flagship product EarthScan™ enables users to see and quantify the climate risk their critical assets are exposed to, such as coastal flooding. Organizations can share this intelligence across stakeholders, to enable democratic, distributed decision-making around a credible and common source of truth.

Using these science-backed insights, organizations can kickstart their adaptation strategies by quickly identifying which assets are most vulnerable to coastal flooding. Then, decide where coastal protection, such as planting mangroves, will be most effective – building a more resilient future for our planet.

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