Blue Carbon

Coastal ecosystems, such as mangroves, salt marshes, and seagrass beds, are able to sequester carbon, also known as blue carbon, through the accumulation of organic material and slow anaerobic decomposition. Mangrove forests sequester carbon at proportionally greater amounts compared to other terrestrial ecosystems, due to their exceptional ability to accumulate sediment and organic matter (Alongi 2020). If degraded, the carbon-rich sediments release significant amounts of greenhouse gases (Alongi 2012), indicating that the protection and restoration of mangroves and the ecosystem services they provide are an important strategy for climate change mitigation. The following articles detail different carbon stock estimates, ecosystem services, and financing possibilities for carbon stored within mangrove ecosystems.

According to Alongi (2012), mangroves act as long-term, century-scale carbon storage that can accumulate significant amounts of carbon under both natural and degraded (e.g., sewage, aquaculture) environmental conditions (Perez et al. 2018). Current estimates of mangrove carbon sequestration range from around 711-766.8 megagrams (Mg) of organic carbon (OC) per hectare (Alongi 2020) up to 900 Mg OC per hectare (Perez et al. 2018), with an average rate of carbon sequestration of about 179.6 g of OC per m² per year (Alongi 2020). To prevent overestimation of global carbon stocks, estimates can be refined by scaling carbon sequestration by area of different sedimentary (i.e., terrigenous or carbonate dominant) and geomorphic (i.e., delta, estuary, lagoon, open coast) settings, which yields a global annual OC burial rate of 20.18 teragrams (Tg) per year (Breithaupt and Steinmuller 2022). Dutta Roy et al. (2024) detail how researchers and practitioners derive these estimates of carbon stocks using a combination of field-based data, remote sensors, and machine learning models.

Literature well represents how blue carbon stocks in mangrove forests support various ecosystem services, such as carbon sequestration and coastal resilience, but Bimrah et al. (2022) also describe synergies between carbon storage and coastal protection ecosystem services. With average soil accretion rates of 5 mm per year (Alongi 2012), mangrove forests can act as a method of resilience against global sea level rise (about 4.5 mm per year [Hamlington et al. 2024]). Mangroves can also provide resilience to tropical storms due to their extensive aerial root systems. Reed et al. (2025) describe how mangroves in Florida, United States, recovered all carbon lost from hurricanes within four years after disturbance, due to storm surges depositing phosphorus-rich sediments that stimulated rapid forest recovery and soil biomass accumulation.

However, mangrove forests only occupy 137,760 km² of the globe, only 0.7% of the total tropical forest area as of 2000 (Giri et al. 2011), limiting their ability to mitigate climate change on a global scale. Mangroves sequester 13.53 gigatons (Gt) of carbon per year globally, whereas other forest ecosystems sequester around 330 to 450 Gt of carbon per year (Alongi 2012). These carbon sequestration estimates suggest that mangrove restoration may be more impactful at national levels, especially for countries experiencing higher levels of degradation due to storm damage or conversion to aquaculture or agriculture (Alongi 2020). For example, mangrove carbon stock loss in Indonesia is high compared to other Southeast Asian countries (about 18,000 ha per year) (Arifanti et al. 2025), and other carbon stock estimates indicate a significant carbon storage potential in Indonesia’s mangroves (Basyuni et al. 2024). Mangroves have also been shown to protect economic activity and reduce damages following tropical storm events, providing both economic and coastal resilience for local communities (Del Valle et al. 2020, Das 2022). These examples of carbon storage potential and coastal resilience demonstrate how mangrove restoration, conservation, and blue carbon crediting could be impactful interventions for national environmental goals.

Carbon crediting schemes can provide financing to protect mangrove ecosystem services and climate change mitigation potential. Zhang et al. (2025) estimate that mangrove restoration projects increase global soil OC stock by 1.35 Tg annually, which could yield $68.6-444 million via blue carbon trading. About 10% of global mangrove forests could be financially profitable at current blue carbon market rates, profitably mitigating 21.6-30.8 Mg of carbon dioxide equivalent (CO₂e) per year (Zeng et al. 2021). For restoration projects where it is not possible to ensure permanent carbon sequestration (e.g., temporarily reduced deforestation, restoration to a timber plantation), there are options for financing through impermanent carbon credits ($80-160 per ton of CO₂e) which is competitively priced with technological carbon offset options ($140 per ton of CO₂e on average) (Balmford et al. 2023). Additionally, the global net benefit-cost ratio of potential mangrove restoration on suitable aquaculture and tidal flat sites is $5.78-13.90, with the ratio increasing over time (Zhang et al. 2025). These numbers show that mangrove restoration can be both ecologically beneficial and economically viable. 

In conclusion, these articles demonstrate that the ecosystem services and carbon sequestration potential of mangrove forests are significant despite the relatively small global area of mangroves compared to other carbon-rich ecosystems. This recognition is necessary to encourage more financial and political support for the conservation and restoration of mangrove ecosystems.

Featured Articles:

Alongi, D.M. (2012). Carbon sequestration in mangrove forests. Carbon Management 3(3): 313-322.

Alongi, D.M. (2020). Global Significance of Mangrove Blue Carbon in Climate Change Mitigation. Sci 2(3).

Arifanti, V.B., Basyuni, M., Suharti, S., Slamet, B., Karlina, E., Sidik, F., Helbert, H., Yeny, I., Yulianti, M., Marwayana, O.N., Macklin, P.A., Rahmania, R., Syadi, S., Wahyuni, T., Halwany, W., Rahmila, Y.I., Faubiany, V., Mubaraq, A., Aznawi, A.A., Ali, H.M. (2025). Assessing the Environmental and Socioeconomic Impacts of Mangrove Loss in Indonesia: A Synthesis for Science-Based Policy. Forest Science and Technology 21(4): 430-446.

Balmford A., Keshav, S., Venmans, F., Coomes, D., Groom, B., Madhavapeddy, A., Swinfield, T. (2023). Realizing the social value of impermanent carbon credits. Nature Climate Change 13(11): 1172-1178.

Basiyuni M., Aznawi, A.A., Rafli, M., Tinumbunan, J.M.T., Gultom, E.T., Lubis, R.D.A., Sianturi, H.A., Sumarga, E., Mukhtar, E., Slamet, B., Jumilawaty, E., Pribadi, R., Sitinjak, R.R., Baba, S. (2024). Harnessing Biomass and Blue Carbon Potential: Estimating Carbon Stocks in the Vital Wetlands of Eastern Sumatra, Indonesia. Land 13(11).

Bimrah, K., Dasgupta, R., Hasimoto, S., Saizen, I., Dhyani, S. (2022). Ecosystem Services of Mangroves: A Systematic Review and Synthesis of Contemporary Scientific Literature. Sustainability 14(19).

Breithaupt, J.L., Steinmuller, H.E. (2022). Refining the Global Estimate of Mangrove Carbon Burial Rates Using Sedimentary and Geomorphic Settings. Geophysical Research Letters  49(18).

Das, S. (2022). Valuing the Role of Mangroves in Storm Damage Reduction in Coastal Areas of Odisha. Climate Change and Community Resilience: 257-273.

Del Valle, A., Eriksson, M., Ishizawa, O.A., Miranda, J.J. (2020). Mangroves protect coastal economic activity from hurricanes. Proceedings of the National Academy of Sciences117: 265-270.

Dutta Roy, A., Pitumpe Arachchige, P.S., Watt, M.S., Kale, A., Davies, M., Heng, J.E., Daneil, R., Galgamuwa, G.A.P., Moussa, L.G., Timsina, K., Ewane, E.B., Rogers, K., Hendy, I., Edwards-Jones, A., de-Miguel, S., Burt, J.A., Ali, T., Sidik, F., Abdullah, M., Pandi Selvam, P., Jaafar, W.S.W.M., Alawatte, I., Doaemo, W., Cardil, A., Mohan, M. (2024). Remote sensing-based mangrove blue carbon assessment in the Asia-Pacific: A systematic review. Science of The Total Environment 938.

Giri, C., Ochieng, E., Tieszen, L.L., Zhu, Z., Singh, A., Loveland, T., Masek, J., Duke, N. (2011). Status and distribution of mangrove forests of the world using earth observation satellite data. Global Ecology and Biogeography 20: 154-159.

Hamlington, B.D., Bellas-Manley, A., Willis, J.K., Fournier, S., Vinogradova, N., Nerem, R.S., Piecuch, C.G., Thompson, P.R., Kopp, R. (2024). The rate of global sea level rise doubled during the past three decades. Communications Earth & Environment 5.

Pérez, A., Libardoni, B.G., Sanders, C.J. (2018). Factors influencing organic carbon accumulation in mangrove ecosystems. Biology Letters 14(10).

Reed, D., Chavez, S., Castañeda-Moya, E., Oberbauer, S.F., Troxler, T., Malone, S. (2025). Resilience to Hurricanes Is High in Mangrove Blue Carbon Forests. Global Change Biology 31(3).

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.

Zhang, J., Lu, Z., Zhou, J., Qin G., Bai, Y., Sanders, C.J., Macreadie, P.I., Yuan, J., Huang, X., Wang, F. (2025). Getting the best of carbon bang for mangrove restoration buck. Nature Communications 16.