Excluding Japan and Australia, only 12 among the 25 countries identified as sources of BCPs, had issued BCCs by March 2025 (Fig. 3a, b). BCCs contributed only 0.35% and 0.91% to the total and to nature-based solutions (NBS) carbon credits issued in the market, respectively22,41. The NBS category includes three main sectors: agriculture, forestry, and wetlands, with BCPs falling under the wetlands subgroup. In 2014, a total of 159,493 BCCs were issued, marking their introduction to the carbon market. The issuance trend has shown a steady upward trend, with the number of issued credits surpassing 1 million by 2020 and then continuing to rise sharply following the entry of Pakistan’s project into the market in 2022, reaching about 6.96 million credits by March 2025 [Supplementary Fig. 5, Supplementary Table 5]. Pakistan holds a 69% share in the BCC market, and its combined market share with India (8%), Senegal (7%), and Indonesia (6%) amounts to ~90% of BCCs issued to date [Supplementary Fig. 6]. All countries issuing BCCs are classified as developing nations or LDCs, except for the US (BCCs from Japan and Australia are not included here due to the lack of available data). According to the most recent data, the average Human Development Index (HDI) of these countries is 0.645, which is below the global average (0.756). China records the highest HDI of BCC source nations at 0.797, ranking 78th globally, whereas Madagascar has the lowest at 0.487, positioned at 183th out of 193. Significantly, four of these countries are in the low human development category42. Consequently, revenue from BCCs plays a critical role in financing both the conservation and restoration of their BCEs, as well as enhancing local community livelihoods24,43.
a Accumulated BCC issuance trends. The graph shows accumulated BCCs issued by country spanning from 2014 to March 15, 2025 identifying key contributors. Data are based on the year credits were issued, not the vintage year. b Geographic Distribution of issued BCCs. The color-coded map indicates total issued BCC by March 15, 2025, with darker shades representing more BCCs issued.
When analyzing BCCs by their vintage year (i.e., the year in which the underlying carbon sequestration occurred), we observe an exponential increase until 2021, followed by a significant drop in 2022. Only a few credits were linked to vintages in 2023, and none appear for subsequent years. By 15 March 2025, a total of 6,961,950 BCCs were introduced into the market, with 3,651,383 of these credits retired and removed from circulation (Fig. 4a), indicating that ~48% of the issued BCCs are still in circulation. Due to the COVID-19 pandemic, BCC retirements temporarily declined between 2019 and 2021, but an upward trend has since resumed (Fig. 4b). In terms of issuance year, BCCs first entered the carbon market in 2014. The number of BCCs decreased by half in 2015 but then showed a consistent upward trend in the following years until 2019, when it experienced a sharp decline. However, BCC issuance increased significantly in 2020, continuing to rise in 2021, and reached its peak in 2022, driven by the issuance of BCC from Pakistan’s large-scale mangrove project. The number of credits issued in 2023 was comparable to 2021 levels, with a significant rise again in 2024 (Fig. 4c).
a Issued and retired BCCs with accumulated trend by vintage year. Dual-axis chart depicts annual issued and retired (bar charts, left axis) against a trend line of accumulated issued BCCs by vintage year (line graph, right axis). b The proportions of retired and remained BCCs by vintage year. Stacked bar chart illustrates the distribution of retired versus remained BCCs, offering insights into market absorption. c Annual issued and accumulated BCCs by issuance year. The dual-axis chart depicts annual issued BCCs (bar charts, left axis) against a trend line of accumulated issued BCCs (right axis) by issuance year.
BCCs find buyers among corporations, individuals, governments, non-governmental organizations (NGOs), and investors worldwide, to offset emissions and demonstrate their commitment to mitigation goals7, by retiring BCCs44. Out of the 1,109,210 BCCs that we tracked, more than 97% were purchased by entities from developed and high-income countries such as the US (42%), European countries (40% with a higher concentration of purchases in the UK and France), Japan (8%), and Canada (7%) (Fig. 5, Supplementary Fig. 7 and Supplementary Table 6). Countries demanding BCC have an average HDI of 0.917, significantly higher than the mean HDI of source countries (0.645)42.
The color-coded map indicating the volume of purchased BCCs (darker = higher volume), and pie charts show the share of end–buyers versus resellers.
Market demand for BCCs is increasing exponentially [Supplementary Fig. 8]. The primary buyers are large-scale entities in various sectors such as technology and software giants (like Apple and Microsoft), transportation (shipping and airlines), pharmaceutical companies, financial and insurance sectors, as well as the steel industry. Notably, some BCPs do not openly trade credits; instead, credits are used to offset the financing company’s carbon footprint. “Mangrove Restoration and Coastal Greenbelt Protection in the East Coast of Aceh and North Sumatra Province”, Indonesia is one such example17. Importantly, not all BCCs are purchased directly by the end buyers; a considerable portion (about 20%) is bought by resellers for speculation, who subsequently resell these credits at higher prices than those allocated to the BCPs’ developers. Unfortunately, resellers do not disclose the final destination of credits, obscuring the final destination and value of 20% of the credits in this study, which is based on the dataset we compiled. Reseller organizations trading BCCs are mostly located in the US, UK, France, Sweden, Switzerland, and Finland (Fig. 5). For instance, ~78% of the BCCs flowing to the UK have been purchased by resellers, whose final destination remains unknown. This share for resellers is considerable and can influence the market price, potentially leading to disproportionate revenues for resellers relative to communities delivering the projects. The development of a fair voluntary carbon market requires full transparency in credit pricing—both in payments made by primary buyers to project owners and by final buyers to intermediaries in resale transactions. A mandatory register of projects under the UN Carbon Offset Platform45, along with integrated digital infrastructures—such as the International Carbon Registry46—can help enhance transparency in the voluntary carbon market.
BCCs mostly flow to the Global North, where cumulative GHG emissions have been greatest, from the Global South, where local communities strongly depend on ecosystem services from blue carbon habitats, while also relying on extractive activities, such as building and agriculture or aquaculture, to derive value from these habitats in the absence of BCPs. Among source countries, Pakistan, Myanmar, and Kenya have sold their BCCs to a wider range of countries, while the BCCs buyers of Senegal, India, and Madagascar were more geographically restricted. Credits originating from projects within China, Australia, and Japan have been sold exclusively within their national borders (Fig. 6).
The links connect source and buying nation, with varying link thickness scaled to the carbon credit volume traded. Australia and Japan have been excluded from this diagram due to the lack of data.
The dynamic interplay between the suppliers and purchasers of BCCs fundamentally influences BCC pricing. Carbon markets are broadly categorized into two types: compliance carbon markets (CCMs), which function under regulatory frameworks mandating emission reductions, and voluntary carbon markets (VCMs), where actors engage in carbon offsetting at their own discretion, without legal compulsion47. BCCs are mainly exchanged in the VCM through Over-The-Counter (OTC) transactions, which are direct, private deals between parties based on verified credits. These deals are formalized through Emission Reduction Purchase Agreements (ERPAs), which outline the terms of the trade, such as quantity, pricing, and delivery of credits, along with any financial arrangements. ERPAs record the agreed price per credit for VCM transactions29. Negotiating the prices of BCCs involves an economic mechanism between the buyer and seller. Several factors, including ecological value, carbon sequestration potential, and market liquidity, affect the market value of BCCs. The bargaining power of the involved parties is an important factor in shaping VCM prices. It is not uncommon for buyers or groups with a large market share to exert significant influence over pricing, highlighting the role of power imbalances in setting the prices within the VCM22,29.
Each BCC corresponds to one metric ton of CO₂ equivalent (t CO₂e). Published reports indicate BCCs are valued between USD 5 and 35 per tCO2e, with mangrove projects commanding higher prices22,29,48. There is currently no accurate or reliable price information available on BCC pricing for many BCPs, and we were able to obtain data for only five projects registered by Plan Vivo and Verra, in addition to the project in Australia and three BCPs in Japan. For Plan Vivo projects, the price started at around USD 6 in 2014 for a project in Kenya and has gradually increased, reaching approximately USD 19 in 2023. Project-specific average prices ranged from USD 12.3 to USD 18 per BCC49,50,51. In comparison, limited data from VCS projects in 2022 showed prices at about USD 27.8 per BCC for Pakistan52, and around USD 15 per BCC for a mangrove project in Colombia [Supplementary Table 7].
Price disparity between BCCs and carbon credit prices in compliance markets is substantial. For example, EU-ETS’s price was USD 6.76 in 2014, surging to USD 86.5 in 2022 and further to USD 96.3 in 2023 and USD 61.3 in 202453 [Supplementary Fig. 9]. Amongst suppliers of BCCs, only three—the US, Japan, and Australia—are classified as developed. We were unable to obtain pricing information for BCCs for the U.S. market. In Japan, however, each BCC is exchanged at a price ranging from 8000 to over 13,158 yen (USD 72.8–119.8) within the country25, which is significantly higher than carbon price under the Tokyo Cap-and-Trade Program (Tokyo CaT)—Japan’s regional emissions trading scheme—where prices averaged USD 49.1 in 2023 and USD 36.9 in 202453. In Australia, BCCs are traded at approximately USD 22.1 per unit54, approximately equal to the 2024 carbon price under the Australian Safeguard Mechanism (USD 21.9)53, a regulatory framework that sets emissions baselines for large industrial facilities and allows compliance through the purchase of carbon offsets.
A weighted average price of USD 26.96 per BCC was calculated using available price data from individual projects, weighted by the number of BCCs issued. This value was then extrapolated to all projects. Assuming that existing and pending BCPs collectively sequester 60.9 Mt CO₂e by 2024, the estimated investment generated from BCC sales could reach approximately USD 1.62 billion. This provides a first order estimate of the size of the market, which is conservative as carbon credits reaching the buyers from resellers likely sell at a much higher price than the average price used to generate this estimate, an assumption that needs be verified when increased transparency in the future allows to assess this hypothesized increase in price.
In most source countries, Indigenous Peoples and local communities actively participate in the projects, with revenues contributing to their livelihoods29, particularly so when located in either LDCs or developing nations. In contrast, the purchasing entities predominantly reside in wealthy, developed countries. Therefore, exchanging BCCs at prices below their real value is unfair and detrimental to the Global South, where BC resources originate. This price disparity reflects broader economic and environmental inequalities, aligning with the climate debt theory, which attributes historical responsibility for environmental damage to high-emitting nations at the expense of low-emitting nation55. Industrialized nations are estimated to have overused their portion of the earth’s carbon budget, accumulating a climate debt of approximately US$192 trillion to developing nations as reparation for over emissions56. Underpriced BCCs further perpetuate this inequality, in effect allowing the Global North to use environmental assets of the Global South without just compensation.
This creates a major inconsistency, whereby buyers in Europe and the U.S. buy BCCs from Kenya and Madagascar at ~25% or less of the regulated value of carbon credits within those nations. In fact, the highest value for carbon credits, by far, was assigned to internally traded BCCs generated by BCPs in Japan. The weighted average price paid for BCC was approximately USD 26.96 for 2022–202349,50,51, compared to the estimated value of carbon in the buying countries of about USD 54.3 (2022–2023)53, indicating that buyers are paying nearly half of what they would if acquiring credits locally. Accordingly, the initial step toward fostering a more equitable market involves gaining a thorough understanding of BCPs and constructing a holistic representation of the BCC market dynamics. As the EU imposes the Carbon Border Adjustment Mechanism (CBAM), taxing imported goods on the carbon impact, it should require carbon credits to be purchased at the point of origin at a level equivalent to taxation rates. For equity, countries like the U.S. and the UK should implement comparable policies, requiring imported carbon credits to be purchased at their recognized worth. Similar policies in compliance markets, such as California’s Cap-and-Trade Program and Singapore’s Carbon Tax, bring carbon consistency across jurisdictions. Adopting similar mechanisms in voluntary carbon markets could prevent BCCs undervaluation and promote fair pricing.
Whereas several assessments have estimated the potential flow of BCCs from BCPs, and a recent analysis30 has analyzed existing projects, our study builds on and extends these efforts by incorporating an updated dataset and providing a detailed examination of real-market transactions, financial flows, and price disparities. Given the critical role of NBSs57, our findings confirm the rapid development of BCPs. While BCPs are growing in significance, they still represent a relatively small portion of the total NBS-related credits. The committed restored area, along with annual and cumulative emission reduction, is substantial, particularly for mangroves. These efforts contribute meaningfully to both climate and biodiversity goals. Further expansion of BCPs is needed to meet their estimated potential of BCPs to offset between 0.5 and 1.38 GtCO2e yr−1 by 20509, with an additional 0.84 (0.62–1.06) GtCO2e yr−1 expected by 2030 through restoration efforts4. Efforts must be made to accelerate the development of BCPs for saltmarshes and, particularly, seagrass meadows, where very large projects, which could potentially surpass the largest existing mangrove project, are being developed for the Bahamas58. In addition, seagrass-based carbon projects are being developed in Japan, the US, Spain, France, Italy, and the UK, and elsewhere, supported by a number of emerging seagrass-specific carbon methodologies, such as Verra’s VM0033 methodology for tidal wetland and seagrass restoration59.
BCPs are efficient, robust, and viable tools for preserving and restoring BCEs, playing a crucial role in the global effort to combat climate change and delivering a broad range of co-benefits. Our analysis does not provide evidence that recent scandals affecting avoidance projects on forests to have impacted the development and price of carbon credits from BCPs26,27. Indeed, many of the projects generate mitigation additionally through restoration efforts, which are far more robust and offer more reliable verification pathways compared to projects issuing credits based on avoidance of emissions resulting from threats to the conservation of BCEs, which all the forest projects involved in the scandals were based upon.
A recent assessment established that, as of the end of 2024, around 2.40 billion carbon credits have been issued in the voluntary carbon market, of which around 56% have been retired60. These credits derive from an inventory of 11,302 carbon projects developed in 143 countries, with emerging and developing countries generating 75.13% of the total carbon credits60. NBS projects generated 38% of the total inventory of credits issued in the voluntary market41. BCPs contributed 0.91% of the NBS credits issued in the voluntary carbon market. While their later entry, beginning in 2014, may partly explain this modest share, other contributing factors likely include methodological complexity, limited eligible ecosystems, and the slower development of standardized protocols, all of which have constrained their growth relative to land-based NBS projects that have been active since 1996.
We showed that, if all existing and pending blue carbon projects fully issue their expected carbon credits, investments in BCCs could amount to at least USD 1.62 billion, highlighting their growing role in climate change mitigation efforts. BCCs are increasingly recognized for their potential to contribute to biodiversity conservation, shoreline protection, food security, and community well-being4. The Kunming-Montreal Global Biodiversity Framework encourages nations to activate NBSs, such as BCPs, to the maximum ambition possible, recognizing the importance of the co-benefits they deliver. Though outstanding efforts have been made regarding BCPs in order to conserve and restore BCEs, projects need to grow 50-fold to meet their full potential, thereby releasing resources to protect BCEs61. BCPs, as a mechanism within the voluntary carbon market, represent a useful and promising path to channel financial flows from developed to developing nations to help meet their biodiversity goals for BCEs. However, these projects should generate equitable and fair financial flows. Yet, our analysis reveals a consistent asymmetry between the value of carbon credits from BCEs sourced from LDCs and developing nations and the value of carbon regulated in receiving developed nations. This pattern reflects more profound inequities in the VCM, where BCCs are often purchased below levels observed in compliance systems. To ensure equity and support SDGs, BCC markets require more transparent and regulated pricing frameworks, not only to ensure price parity between developing and developed nations, but also to recognize the true value of BCPs to advance SDGs. Projects should, in the future, recognize, document, and quantify the full spectrum of benefits derived from BCPs, which include both ecological and social benefits addressing multiple SDGs, and build a premium on the price for the contributions of the BCPs to rebuild natural and social capital.
We appeal to regulators of nations importing carbon credits to demand transparency in reporting by the projects, including establishing transparent registers to track final buyers beyond resellers, reducing speculative trading, and ensuring the disclosure of prices paid by final recipients for BCCs. Increasing BCPs transparency is key to supporting and building BCPs under strengthened governance that will ultimately harmonize voluntary and compliance carbon markets. Enhancing the transparency of BCPs and avoiding the current gap in carbon price paid to developing nations by importers relative to that in their markets will contribute to stabilizing the emerging yet crucial blue carbon market while enhancing investor confidence both in the quality of the projects and their ethical integrity.
Furthermore, an essential consideration is that BCC pricing must adequately cover the costs associated with implementing and maintaining BCPs to ensure their long-term viability. Recent research highlights the differences of carbon pricing, and the cost-effectiveness of BCPs, and shows the gap between the price of credits on the voluntary market and the true worth of the credits62. Research in the future should continue investigating mechanisms for realizing equitable pricing frameworks that capture both the carbon sequestration potential and extensive ecological and socio-economic advantages of BCPs.
