Beyond Green Infrastructure: Valuing Mangroves in Flood Protection and National Wealth

The World Bank report emphasizes mangroves’ critical role in flood protection, valuing them at $855 billion globally for shielding lives and infrastructure. It urges enhanced conservation efforts, showing mangroves as both economic assets and vital defenses against climate impacts.

The recent World Bank report, authored by experts from the University of California, Santa Cruz, and the Instituto de Hidráulica Ambiental-IH Cantabria, alongside contributions from World Bank researchers, provides a thorough analysis of the economic and protective value of mangroves as a critical natural defense against coastal flooding. With the rising intensity of climate change-induced coastal risks, the report emphasizes that mangroves serve as an essential buffer, reducing wave energy, and storm surges, and protecting both lives and assets in coastal areas around the world. Using robust global risk models, this study estimates how mangroves help avoid flood damages across varied storm frequencies by comparing flood exposure in scenarios with and without mangrove protection. The findings, covering the period from 1996 to 2020, reveal that mangroves have mitigated substantial flood risk and increased economic value as global coastal populations and assets grow. Despite their significant protective value, mangroves are under threat, with nearly 4% of global mangrove cover lost from 1996 to 2010 due to factors such as shrimp farming and urban expansion in areas like Indonesia, Mexico, and Myanmar. Though mangrove loss slowed to less than 1% from 2010 to 2020 due to improved conservation efforts and national commitments, many regions still face ongoing challenges.

Rising Economic Benefits of Mangroves

The report underscores the economic impacts of mangrove loss, noting that even a modest reduction in mangrove cover can lead to substantial increases in flood risk. Globally, the flood protection benefits provided by mangroves were valued at 855 billion dollars in 2020. China, Vietnam, India, Australia, and the United States rank among the top beneficiaries, with each experiencing significant reductions in annual flood risk due to their coastal mangrove forests. In regions like the U.S. and Australia, the primary value of mangroves lies in their ability to protect capital assets and infrastructure, where the cost of flood-related damages would otherwise be devastating. Between 2010 and 2020, the benefits of flood protection from mangroves grew more rapidly than flood risks for the first time, largely because increasing numbers of people have settled in areas safeguarded by mangrove forests. This shift is significant; it suggests that mangroves’ role in national wealth is becoming more apparent, especially in economies that recognize the value of natural assets in reducing climate risks.

Social Value and Resilience in Low-Income Countries

Socially, the protective value of mangroves is especially crucial in low- and middle-income countries where they provide a critical shield for vulnerable coastal communities. For example, in countries such as Bangladesh, the Philippines, and Vietnam, large sections of the population depend on mangroves not only for their livelihoods but also as a defense against natural disasters. Here, each hectare of mangroves plays a critical role in risk reduction, protecting highly populated, low-income areas from the impacts of severe storms and floods. This contrasts with high-income countries where mangroves’ value is largely tied to their economic protective benefits; nonetheless, these areas still rely on mangroves to mitigate infrastructure and capital losses. The study found that, while high-income nations like the United States benefit from the protection of capital assets in mangrove-rich areas, the social benefits are more pronounced in countries with lower income levels. This is especially true in the Middle East and North Africa, where each hectare of mangrove can protect up to 10 people from flood risks, compared to the Latin America and Caribbean regions where fewer people live in mangrove-protected zones, reducing their per-hectare social value.

Economic Growth Drives Rising Mangrove Value

The economic valuation of mangroves continues to evolve, with the report demonstrating the significant increase in their asset value over recent decades. The analysis shows that from 1996 to 2020, the global value of mangroves for flood risk reduction increased markedly, with asset values rising by 130 billion dollars from 1996 to 2010 and 502 billion dollars from 2010 to 2020. This dramatic increase reflects the rising socioeconomic growth along coastlines, where an influx of people and infrastructure demands greater protection from natural defenses like mangroves. Coastal resilience efforts increasingly recognize the high asset value of mangroves as a financial and ecological investment. In China, Vietnam, and Australia, for instance, the economic benefits of mangroves in terms of flood risk reduction reach tens of billions of dollars each year, underscoring their role in climate adaptation policies and risk management strategies.

Policy and Financial Innovations for Mangrove Conservation

The World Bank report calls for enhanced mangrove management, not only to maintain these ecosystems but to support their expansion as a means of bolstering climate resilience. Restoring mangrove forests is a proven, scalable practice, and recent years have seen an increase in international support for such efforts. Countries experiencing high coastal risks are encouraged to integrate mangrove conservation into climate and disaster risk reduction policies. The economic incentives for mangrove preservation are clear: they provide cost-effective protection compared to traditional “gray” infrastructure like seawalls and support biodiversity and carbon sequestration. The report suggests innovative financing mechanisms, including blue bonds, insurance incentives, and catastrophe bonds, as viable methods to support mangrove conservation. These financial tools could leverage the protective services of mangroves, translating their ecological benefits into tangible economic returns. Additionally, integrating mangrove conservation with other climate adaptation strategies, such as coral reef restoration, can amplify protective benefits and increase overall resilience.

Integrating Mangroves in National Wealth and Climate Strategy

The findings underscore the importance of valuing natural assets such as mangroves in national economic accounts, particularly for low-income nations that rely heavily on these ecosystems for climate adaptation. By recognizing mangroves as valuable natural capital, governments can make informed decisions about investing in and restoring these ecosystems. As the report suggests, mangroves should be part of an integrated approach to coastal management, combining nature-based solutions with infrastructure planning for sustainable, long-term climate resilience. With over 120 countries possessing mangrove forests, the report offers a comprehensive framework for global mangrove management, guiding policymakers in balancing economic development with environmental conservation. The World Bank’s ongoing efforts in producing comprehensive wealth accounts aim to encourage countries to incorporate ecosystem services into economic planning, ensuring that the wealth generated by these ecosystems benefits future generations.