Home to one-third of all mangroves globally, Southeast Asia has outsize potential to lock away greenhouse gases in these carbon-dense ecosystems. But deforestation for a range of commodities, cyclone damage, and rising sea levels severely jeopardize the region’s capacity to lean on its mangroves as nature-based solutions to climate change.

A new study shows that 1.8 million hectares (4.4 million acres), or 85%, of Southeast Asia’s mangrove forests considered viable for blue carbon credit investments are at risk of destruction due to the expansion of oil palm, rice and aquaculture over the next 25 years.

The study, published in the journal Communications Earth & Environment, concludes these pressures undermine the integrity of blue carbon credits as a way of funding conservation. This could make it more challenging for policymakers and conservationists to realize the true potential of mangroves for mitigating global biodiversity and climate challenges, the authors say.

“It’s sort of a reality check — we can’t really rely 100% on carbon markets to conserve mangroves,” study co-author Yiwen Zeng, a conservation scientist at the Nanyang Technological University in Singapore, told Mongabay.

Hectare for hectare, mangroves can store up to five times more greenhouse gases than rainforests, making them a key focus of blue carbon credits. The viability of these credits, which are typically bought by firms looking to offset their emissions, is contingent on the mangrove forest remaining intact and thus locking away carbon in biomass or sediments.

There are 4.7 million hectares (11.6 million acres) of mangrove forests in Southeast Asia, roughly 45% of which are potentially eligible for carbon finance projects, the study found. Habitats are typically only eligible for carbon credit programs if they’re under immediate threat of destruction if left unprotected by a conservation intervention.

The team led by Valerie Kwan, a researcher at the University of Queensland in Australia, used models to investigate the “permanence” of carbon storage in these investible areas. They found conversion to aquaculture poses the greatest risk to mangroves in the region, followed by oil palm and rice cultivation, with hotspots of future deforestation in Indonesia, Cambodia and the Philippines. They also factored in the risk of damage from cyclones and sea-level rise, both of which are expected to worsen with climate change.

Given that mangroves are carbon sequestration powerhouses, the combined threats could severely hamper regional progress toward reducing greenhouse gas emissions through nature-based solutions. This is especially pertinent in Southeast Asia, a region that contributes roughly one-third of the world’s total land-use emissions.

A separate study led by Sigit Sasmito, a researcher at James Cook University in Australia, shows that conserving and restoring Southeast Asia’s mangroves and peatlands could halve the region’s annual land-use emissions — cutting global emissions from land use by roughly 16%.

This is impressive given these ecosystems cover just 5.4% of Southeast Asia’s land area, according to Sasmito: “By investing in the conservation of peatlands and mangroves, Southeast Asia can lead the world in deploying cost-effective, nature-based solutions that deliver enduring climate and biodiversity benefits.”

Kwan and her colleagues found the land-use and climate-related risks they considered in their study potentially jeopardizes 15.9 million metric tons of carbon sequestration each year. Not to mention the loss of crucial wildlife habitats, fisheries, and coastal protection that mangroves also provide.

Diverse funding options

While carbon credits and carbon markets have drawn much criticism from the conservation community, with many labeling them a distraction for firms that should be eliminating greenhouse gas emissions across their activities, they’re also often recognized as a way of channeling much-needed funding toward conservation.

However, Kwan and her colleagues also calculated that at current market prices, blue carbon credits are likely to only generate more revenue than commodity production in 37% of Southeast Asia’s investible mangrove area. Even at $200 per metric ton of sequestered carbon, almost seven times the rate the researchers used, blue carbon credits couldn’t cover the full costs of conservation.

Carbon credits are inevitably going to be part of the conservation financing mix for carbon-dense mangroves, Zeng said. But given their limits and the pressures on natural ecosystems, other conservation funding options will be vital, he said. Blended finance options that combine public, charitable and private investments are a promising avenue, he added.

Policymakers could also address the threat of deforestation by aligning land-use policies with climate and biodiversity goals, Zeng said, and ensuring benefits are equitably shared with local communities. Policies and frameworks that acknowledge and value the other ecosystem services provided by mangroves, such as coastal protection, could also help.

“A combination of both policy interventions and bundling of different ecosystem services together with carbon or climate change mitigation potential might bring in more investment and support,” Zeng said. “The combination of all these things can maybe flip the dynamic that we’re seeing right now of mangrove conservation not necessarily generating more revenue than land could otherwise generate through conversion.”

Protected areas could also play a more pivotal role in mangrove protection in the region, the study notes. Despite their densely forested coastlines, for instance, Malaysia, Papua New Guinea and Myanmar formally protect less than 5% of their mangroves, according to the Global Mangrove Alliance’s 2024 State of the World’s Mangroves report. Meanwhile, Indonesia, home to a fifth of the world’s mangroves, only protects 15%.

Zeng said investment in community-based conservation projects outside of these formally protected areas will be key to ensure mangroves stay standing throughout the region.

“The world is moving toward protecting 30% of land and sea areas by 2030,” Zeng said. “And I would say that mangroves are a good place to start, because they have all these additional ecosystem services, they should be a conservation priority.”

Banner image: A researcher notes biomass measurements in a mangrove forest in West Kalimantan, Indonesia. Image by Kate Evans/CIFOR via Flickr (CC BY-NC-ND 2.0).

Carolyn Cowan is a staff writer for Mongabay.

Citations:

Kwan, V., Friess, D. A., Sarira, T. V., & Zeng, Y. (2025). Permanence risks limit blue carbon financing strategies to safeguard Southeast Asian mangroves. Communications Earth & Environment, 6(1). doi:10.1038/s43247-025-02035-4

Sasmito, S. D., Taillardat, P., Adinugroho, W. C., Krisnawati, H., Novita, N., Fatoyinbo, L., … Lupascu, M. (2025). Half of land use carbon emissions in Southeast Asia can be mitigated through peat swamp forest and mangrove conservation and restoration. Nature Communications, 16(1). doi:10.1038/s41467-025-55892-0

Zeng, Y., Friess, D. A., Sarira, T. V., Siman, K., & Koh, L. P. (2021). Global potential and limits of mangrove blue carbon for climate change mitigation. Current Biology, 31(8), 1737-1743.e3. doi:10.1016/j.cub.2021.01.070

See related story:

Protecting peatlands and mangroves could halve Southeast Asia’s land-use emissions

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