A new global study shows that mangroves provide billions of dollars worth of flood risk reduction benefits every year.
The natural coastal defenses provided by mangrove forests reduce annual flooding significantly in critical hotspots around the world. Without mangroves, flood damages would increase by more than $65 billion annually, and 15 million more people would be flooded, according to a new study from the University of California.
“Mangroves provide incredibly effective natural defenses, reducing flood risk and damages,” said Pelayo Menéndez, first author of the paper, in a statement.
Climate change is increasing the risk of coastal flooding through its effects on sea level rise and the intensity of hurricanes. According to the study’s authors, conservation and restoration of natural defenses such as mangroves offers cost-effective ways to mitigate and adapt to these changes.
The researchers provided high-resolution estimates of the economic value of mangrove forests for flood risk reduction across more than 700,000 kilometers of coastlines worldwide. They combined engineering and economic models to provide the best analyses of coastal flood risk and mangrove benefits.
Their results show when, where, and how mangroves reduce flooding, and they identified innovative ways to fund mangrove protection using economic incentives, insurance, and climate risk financing.
Many mangroves have been lost to aquaculture and coastal development, including the construction of public infrastructure such as ports and airports. The loss of mangrove forests leads to increased coastal flooding, but these forests can be easily restored to make people and property safer, according to the statement.
The new study rigorously valued the social and economic coastal protection benefits provided by mangroves globally. Many 20-kilometer coastal stretches, particularly those near cities, receive more than $250 million annually in flood protection benefits from mangroves.
The researchers are working with insurance companies, the World Bank, and conservation groups to use these results for risk reduction and conservation.
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