Mangroves have been shown to provide $855 billion in flood protection services worldwide, according to a new study from the Center for Coastal Climate Resilience at UC Santa Cruz. The research, conducted by project co-lead, Pelayo Menendez and center director, Michael W. Beck, is featured in the World Bank’s 2024 edition of The Changing Wealth of Nations.
The study, titled Building Coastal Resilience with Mangroves: The Contribution of Natural Flood Defenses to the Changing Wealth of Nations, highlights the essential role mangroves play in protecting coastal communities from floods, storm surges, and erosion, offering significant benefits to both people and national economies. As climate change accelerates the frequency and severity of storms, the need for effective coastal defenses has become increasingly urgent. Traditionally, governments have turned to hard infrastructure like seawalls and levees to guard against floods. However, the center’s study reveals that natural ecosystems — particularly mangroves — can be equally, if not more, effective as coastal defenses, while providing additional environmental benefits.
Mangroves were first included as coastal protection assets by the World Bank in the 2021 edition of The Changing Wealth of Nations. This new research expands upon that earlier work by incorporating updated global data from 2020, offering a clearer picture of mangroves’ protective value over time. Using advanced flood risk models, Menendez and Beck analyzed mangrove forests in 121 countries, covering 700,000 kilometers of subtropical coastlines.
The study finds that the value of mangroves for flood-risk reduction is rising dramatically, in large part because of increasing populations, wealth and storms on coastlines around the world. From 1996 to 2010, the value of mangroves for flood-risk reduction increased by $130 billion, and from 2010 to 2020, mangrove long-term benefits rose by an additional $502 billion. Despite some declines in mangrove cover — driven by factors such as shrimp farming and coastal development — their value as flood buffers grew as more people and infrastructure came to rely on their protection.
“The results are clear: Mangroves play a critical role in reducing flood risks and should be viewed as valuable natural assets,” Menendez said. “They offer cost-effective protection to coastal communities and support national wealth by preserving lives, livelihoods, and infrastructure.”
The research goes beyond the environmental importance of mangroves, underscoring their economic value as natural capital assets. The $855 billion figure represents the present value of mangroves’ flood protection services, i.e., the benefits of this natural infrastructure over the next 100 years. The countries benefiting most from these services every year include China, Vietnam, Australia, the United States, and India.
The study also shows that while mangrove loss continued from 2010 to 2020, the rate of decline slowed significantly to just 0.66 percent. In that same period, the protective benefits provided by mangroves grew even faster than the overall flood risk. This marks a turning point, with mangroves protecting 61 percent more people and safeguarding 109 percent more capital assets from floods in 2020 compared to a decade earlier.
Countries like Vietnam, Bangladesh, India, China, and Cameroon benefited most from these gains, with mangroves protecting hundreds of thousands of people each year. On the other hand, countries such as Malaysia, Myanmar, and Taiwan saw a decline in mangrove benefits, highlighting the need for increased conservation efforts in these regions.
The findings come at a critical time as countries around the world search for sustainable solutions to rising climate risks. Mangroves offer a natural, cost-effective solution to flood protection, making them an essential component of any climate-adaptation strategy.
As governments and policymakers look to the future, the study provides a compelling case for investing in the conservation and restoration of mangroves. “Protecting and restoring mangroves isn’t just good for the environment — it’s a smart economic choice,” Beck said. “These ecosystems provide invaluable services that help build resilience against the growing threats of climate change.”
The Center for Coastal Climate Resilience has also released these results and data as part of the Coastal Resilience Explorer decision-support tool.
