Their conclusion: investing in mangroves pays off. The study, “Mangrove restoration and coastal flood adaptation: a global perspective on the potential for hybrid coastal defences,” was published in PNAS.
A natural barrier against sea-level rise and coastal flooding
Mangrove forests function as a living coastal defense. The tangle of roots dampens incoming waves and thus reduces the force with which water reaches the coast. By combining this natural buffer with existing dikes and other infrastructure, a robust system is created that is better able to withstand the effects of sea-level rise.
Preventing billions in damage
Tiggeloven and his colleagues calculated that restoring mangroves along flood-prone coastlines could save about 800 million dollars per year in flood damage. In addition, around 140,000 people per year would be exposed to flooding less often. In roughly half of the 208 coastal regions studied, mangrove restoration proves to be economically viable.
The societal return is impressive: globally, the benefits are three to six times greater than the costs, amounting to an estimated net value of 44 to 125 billion dollars.
Greatest gains for the disadvantaged
Notably, it is precisely disadvantaged coastal communities that benefit most from mangrove restoration. They often live in areas where flood risk is highest and protection is most urgently needed. Restoring mangroves can not only protect lives and infrastructure, but also contribute to poverty reduction and local resilience.
An investment in the future
“Our research underscores that mangrove restoration is not only an ecological choice, but also a smart economic decision. By investing now in these natural buffers, countries can better protect themselves against the growing impacts of climate change while at the same time improving the living conditions of millions of coastal residents,” says Tiggeloven.
Photo: Saplings of Rhizophora planted behind protective bamboo structures in front of eroding natural mangrove forest in Central Java, Indonesia (Image credit: Bregje Van Wesenbeeck)
