Making the most of mangroves in the fight against climate change

The vast expanse of mangroves bordering Bangladesh's southern coast, the Sundarbans, is far more than a scenic tourist destination. As a sui generis ecosystem, it stands as a natural frontline defence against climate change through its dynamic intertidal forests, protecting coastal communities while sustaining extraordinary biodiversity.

As climate threats escalate, discussions on coastal climate resilience and disaster management often gravitate towards technocratic grey infrastructure such as embankments, while the most vital solution is already rooted in our soil. Mangroves are not merely nature's ornamental gift; they are a life-sustaining shield for a nation standing on the edge of a climate precipice.

The science of resilience

The Sundarbans' ability to protect Bangladesh's coast lies in the way mangroves interact with water and wind.

The intricate fluid dynamics of pneumatophores, or aerial roots, together with dense tree trunks, act as a biological breakwater against strong winds and wave action. Studies show that a healthy mangrove belt can reduce water flow by 29% to 92% and wave height by 13% to 66% over just 100 metres of forest.

Similarly, contemporary research on blue carbon shows that mangroves can store up to four times more carbon per hectare than other terrestrial forests, helping remove carbon dioxide from the atmosphere. 

Indigenous mangrove species provide natural protection against a wide range of climate-related hazards. Few other ecosystems can match this "climate multi-tasking" by attenuating wave energy, stabilising shorelines and reducing damage to settlements and agriculture.

For Bangladesh, these benefits are crucial. 

Storm surges can rise as high as six metres during severe cyclones, and mangroves serve as vital green infrastructure that complements embankments by reducing damage, lowering maintenance costs and decreasing the risk of catastrophic breaches, while simultaneously protecting ecosystems. 

Their extensive root systems also limit coastal erosion and slow the intrusion of saline water into fertile farmland. Moreover, the ecosystem sustains local communities by providing fish, honey, timber, fuelwood and other natural resources that support livelihoods and traditional ways of life.

Past scars

Bangladesh's coastline has endured a relentless cycle of cyclones and tidal surges that have left lasting scars on the Sundarbans. Although mangroves are remarkably resilient, repeated exposure to increasingly intense storms has led to significant forest degradation.

During Cyclone Sidr in 2007, a Category Four super cyclone, experts estimated that the Sundarbans absorbed nearly half of the storm's energy before it reached populated areas. The value of this natural shield becomes even clearer when it is weakened. In the years that followed, the combined effects of mangrove loss and rising salinity contributed to crop failures across Khulna and Satkhira, accelerated livelihood losses and increased climate-induced migration.

Before the region had fully recovered from Sidr, Cyclone Aila struck in 2009, damaging an estimated 30% to 35% of the Sundarbans' vegetation. These back-to-back disasters underscored a sobering reality: while mangroves protect us from climate extremes, they too require protection if they are to continue safeguarding Bangladesh's coast.

The way forward

As climate-induced disasters become more frequent and intense, coastwide mangrove afforestation, reforestation and conservation have become imperative. 

Their value extends beyond environmental protection through a triple dividend: carbon finance, stronger local livelihoods and reduced disaster risk, while also fostering community stewardship and cultural enrichment.

Only in recent decades have mangroves gained formal recognition as a climate solution, despite having served as nature's own adaptation mechanism for centuries.

Today, both the government and non-state actors are investing in these ecosystems as part of Bangladesh's growing blue carbon strategy.

More recently, the Bangladesh Bondhu Foundation, in partnership with the Bangladesh Forest Department and the Ministry of Environment, Forest and Climate Change, launched the Carbon Sequestration through Mangrove Afforestation and Restoration in Bangladesh (CASMAR) initiative, marking one of Bangladesh's first steps into the voluntary carbon market.

During Cyclone Sidr in 2007, the Sundarbans absorbed nearly half of the storm's energy before it reached populated areas. On the contrary, in the years that followed, the combined effects of mangrove loss and rising salinity contributed to crop failures across Khulna and Satkhira, accelerated livelihood losses and increased climate-induced migration.

Alongside these efforts, corporate and development organisations are pioneering new conservation models. Korea's HYBE, the entertainment company behind the globally renowned K-pop group BTS, has supported the planting of more than 4.6 lakh mangrove trees in Bangladesh over the past three years, highlighting the growing role of carbon sequestration in corporate social responsibility.

Give Bangladesh Foundation's Project Oxygen is scaling up a community-driven mangrove restoration programme that complements tree planting through long-term aftercare, promotes youth-led stewardship and community ownership, and explores innovative financing through partnerships and future participation in voluntary carbon markets.

The policy foundation for this transition is already in place. Under the 2024 UN Convention on Biological Diversity, Bangladesh committed to restoring 15% of its degraded terrestrial, coastal, freshwater and marine ecosystems by 2030. Likewise, the National Adaptation Plan (2023–2050), the Third Nationally Determined Contribution (NDC) and the Bangladesh Delta Plan 2100 all identify afforestation and mangrove restoration as central pillars of climate resilience. The government's commitment to plant 250 million trees over the next five years, including mangroves, further reflects this national ambition to build a more climate-resilient Bangladesh.

The Sundarbans are estimated to store around 230 million tonnes of carbon, making them one of the world's most significant natural carbon banks, valued at as much as Tk188 billion. Bringing these carbon stocks into international voluntary carbon markets could unlock billions in climate finance if governed transparently. It could also create a self-sustaining cycle in which private-sector investment finances ecosystem restoration, strengthens climate resilience, supports local livelihoods and contributes to Bangladesh's climate commitments.

A call to protect our green guardians

As the world marks the International Day for the Conservation of the Mangrove Ecosystem, the Sundarbans should be recognised as more than an ecological reserve. They are also one of Bangladesh's most sophisticated natural infrastructures, strengthening the country's ability to withstand climate change while creating significant opportunities through international carbon markets.

Every mangrove sapling planted today is an investment in a safer and more climate-resilient future. As global temperatures continue to rise, the green walls we strengthen today will determine whether Bangladesh's coastal heartlands can thrive as a global model of resilience. Investing in mangroves is therefore no longer an option; it is one of our strongest safeguards against the uncertainties of a changing climate.

Sanjana Labiba is a climate and development research enthusiast.

Disclaimer: The views and opinions expressed in this article are those of the author and do not necessarily reflect the opinions and views of The Business Standard.