The ocean is foundational to human societies worldwide. Its vast ecosystems—from coral reefs to mangrove forests—and essential infrastructures like seaports make up what is termed ‘blue capital.’ This natural and built marine wealth supports food security, livelihoods, tourism, and global trade, creating immense economic and social value. Yet, climate change poses existential risks to these assets through ocean warming, acidification, sea-level rise, and extreme weather, leading to widespread degradation. Until now, these ocean-related damages have been largely absent in popular climate cost assessments, creating a critical blind spot in understanding the true costs of carbon emissions.

To close this gap, a consortium of environmental economists and marine scientists developed a novel integrated assessment model, enriching traditional approaches by embedding rigorous marine impact science. Their framework specifically quantifies the climate-induced degradation of multiple ocean systems—coral reefs suffering bleaching events, collapsing mangrove forests, deteriorating seaport infrastructure threatened by sea-level rise and storms, alongside shrinking fisheries and mariculture yields curtailed by shifting ocean conditions. This comprehensive synthesis links ecological changes with economic consequences that ripple through global welfare.

The model’s outputs deliver a startling conclusion: the ocean’s climate-related costs add approximately US$48 per ton of carbon dioxide emitted as of 2020, with a bootstrapped confidence interval ranging from US$38 to US$70. This ocean-inclusive figure nearly doubles the SCC value derived from models excluding marine impacts, signaling substantial hidden costs. When the analysis applies a more conservative discount rate of 2%—reflecting increased emphasis on future generations’ welfare—the blue SCC skyrockets to US$168 per ton of CO2, suggesting oceans greatly amplify carbon’s economic externality.

Understanding this augmented social cost of carbon has profound implications for policymaking. Current carbon pricing mechanisms, climate damage assessments, and emission reduction targets are based on SCC values that may substantially undervalue the benefits of aggressive climate mitigation. Incorporating ocean-driven damages into these calculations provides governments and international bodies empirical evidence underscoring the imperative for more ambitious climate action, aligning economic signals with the true scale of environmental risks.

The scientific rigor and interdisciplinary approach of the research stand out as hallmarks of its credibility. By leveraging the most up-to-date oceanographic data and employing cutting-edge ecological-economic modeling, the research team precisely maps ocean climate vulnerability onto global welfare metrics. This integration moves beyond simplistic or static methodologies, capturing dynamic feedbacks and regional heterogeneities that more accurately reflect real-world conditions and economic dependencies on the marine environment.

Coral reefs represent one of the most visibly impacted ecosystems. Climate-driven warming causes recurrent coral bleaching, reducing reef structural complexity and undermining biodiversity hotspots. This degradation translates into diminished fisheries productivity and tourism revenue, livelihoods loss, and erosion of shoreline protection services. The model quantifies these adverse outcomes, attributing significant economic damages to coral decline that were previously missing from standard SCC estimates.

Likewise, mangrove ecosystems, vital carbon sinks and protective coastal buffers, are imperiled by rising temperatures, altered precipitation regimes, and intensified storm activity. Their loss accelerates carbon emissions stored in blue carbon reservoirs and exposes coastal communities to flooding and erosion. Inclusion of mangrove degradation magnifies the overall social cost of carbon by capturing these cascading ecosystem service failures, further contributing to the sharply elevated ocean-inclusive SCC values.

Critical infrastructure, such as seaports, faces increasing vulnerability from sea-level rise and extreme weather events associated with climate change. Damage to these nodes disrupts global supply chains and trade flows, generating large-scale economic reverberations. Modeling these infrastructure impacts within the SCC framework reveals significant additional costs that accentuate the economic stakes of unabated carbon emissions and the importance of resilience investments.

Fisheries and mariculture are two major ocean-dependent economic sectors that climate change threatens through alterations in ocean temperature, chemistry, and circulation patterns. These shifts affect fish stock distributions, productivity, and the viability of aquaculture operations. By embedding fisheries and mariculture losses into the social cost of carbon, the assessment integrates vital food security and economic risks hitherto underestimated in climate policy debates.

The enhanced understanding provided by this holistic ocean-inclusive SCC approach marks a paradigm shift in climate economics. It underscores the interconnectedness of marine health and human welfare, emphasizing how environmental degradation in oceans exacerbates the broader societal costs of carbon emissions. This research lays the groundwork for integrating ocean-centric perspectives into global carbon pricing frameworks, potentially influencing climate negotiations, carbon markets, and funding priorities.

Moreover, the findings encourage cross-sector cooperation, bridging ocean science, environmental economics, and policy design. By articulating the economic ramifications of ocean ecosystem loss and infrastructure damage, the analysis empowers stakeholders to advocate for integrated conservation and adaptation strategies. These encompass emission reductions, marine protected areas, coastal defenses, and sustainable fisheries management—all essential components for minimizing the elevated blue social cost of carbon.

The profound increase in the social cost of carbon due to ocean impacts also brings ethical considerations to the fore. It highlights how vulnerable communities, especially those reliant on marine resources, may bear disproportionate burdens from climate change. The elevated blue SCC therefore strengthens the argument for climate justice and the need for targeted support mechanisms within global climate frameworks.

Importantly, this research opens avenues for future exploration. As ocean science advances and modeling techniques refine, even greater resolution and accuracy can be realized, encompassing additional blue capital components such as deep-sea ecosystems, offshore renewable infrastructure, and ocean-based carbon sequestration technologies. Such inclusions could further recalibrate social cost estimates and inform adaptive governance in marine contexts.

In summary, accounting for ocean impacts reveals that our previous understanding of carbon’s social cost was severely incomplete. By nearly doubling the social cost of carbon, this pioneering work exposes the monumental economic risks tied to ocean degradation and redefines the stakes for climate mitigation policies. The ocean, often labeled the planet’s life support system, must be central in climate-economic assessments to ensure comprehensive, just, and effective solutions to the global climate crisis.

This transformative integration of marine science into climate economics robustly demonstrates that protecting ocean health is not only an environmental imperative but an economic necessity. Policymakers, economists, and environmentalists alike must now confront this amplified social cost of carbon, shaping climate strategies that truly reflect the interconnected nature of Earth’s systems and human prosperity.

Subject of Research: Climate-economy modeling integrating ocean ecosystem and infrastructure impacts on the social cost of carbon.

Article Title: Accounting for ocean impacts nearly doubles the social cost of carbon.

Article References:
Bastien-Olvera, B.A., Aburto-Oropeza, O., Brander, L.M. et al. Accounting for ocean impacts nearly doubles the social cost of carbon. Nat. Clim. Chang. (2026). https://doi.org/10.1038/s41558-025-02533-5

Image Credits: AI Generated

DOI: https://doi.org/10.1038/s41558-025-02533-5

A transformative approach to addressing these issues involves the application of environmental accounting principles traditionally used in terrestrial settings to the marine domain. By systematically quantifying the natural capital and ecosystem services provided by marine environments, policymakers can gain a more comprehensive understanding of the true value of oceanic resources beyond mere extractive outputs. This methodology enables the integration of ecological data with socio-economic parameters, fostering transparency and accountability in the use and management of marine ecosystems. Such an integrative framework is essential for formulating evidence-based policies that align with sustainable development objectives.

Marine ecosystems function as complex, dynamic systems that underlie a host of critical ecosystem services. Among these, atmospheric regulation through carbon sequestration plays a crucial role in mitigating climate change. Seagrass meadows, for instance, are highly efficient carbon sinks, storing organic carbon in sediments and biomass at rates dwarfing terrestrial forests. Likewise, mangrove forests act as natural buffers, absorbing wave energy and reducing coastal erosion, thereby protecting infrastructure and human lives. Coral reefs contribute substantially to biodiversity hotspots and sustain fisheries by providing habitats critical for numerous marine species. Recognizing these intrinsic relationships highlights the multifaceted contributions of marine natural capital to human well-being.

Despite growing awareness, marine habitats in China have not been immune to anthropogenic pressures. Industrial runoff and untreated sewage discharge have led to eutrophication and diminished water quality in numerous coastal regions. Additionally, climate-induced coral bleaching events have threatened reef resilience, while overfishing has disrupted food web dynamics and diminished fish stocks critical for food security. These stressors cumulatively undermine ecosystem functionality and services, with cascading effects that extend to economic sectors such as fisheries and tourism. Therefore, conservation efforts must be reinforced by stringent environmental governance underscored by accurate ecosystem accounting.

The synthesis of high-resolution spatial and temporal data using remote sensing, in situ measurements, and ecological modeling forms the backbone of effective ocean accounting systems. China’s advancements in satellite technology and marine monitoring provide an unprecedented opportunity to develop province-based marine natural capital accounts. These accounts can quantify ecosystem conditions and service flows, thereby enabling the assessment of trade-offs between development and conservation. Moreover, they facilitate the identification of priority areas for protection or restoration and aid in monitoring policy effectiveness over time.

An emerging consensus underscores that the value of marine ecosystems extends well beyond market-based valuations. Cultural, recreational, and aesthetic values contribute substantially to societal welfare and are integral to the identity and heritage of coastal communities. Incorporating these non-market values into ocean accounting frameworks necessitates interdisciplinary approaches, combining ecological science with social science methodologies. Survey instruments, participatory mapping, and qualitative assessments can capture community perspectives and preferences, enriching the data used to inform governance decisions.

Policy frameworks anchored in comprehensive marine accounting have the potential to transform marine resource management in China. By embedding sustainability metrics into economic planning, ocean accounting can shift the paradigm from short-term exploitation to long-term stewardship. For example, integrating natural capital values into development cost-benefit analyses can disincentivize environmentally damaging projects and prioritize investments in ecosystem restoration. Furthermore, marine natural capital accounting aligns with international frameworks such as the Convention on Biological Diversity and the United Nations Sustainable Development Goals, reinforcing China’s commitments to global sustainability efforts.

The adoption of ocean accounting also promises to yield significant co-benefits in food security. Sustainable management of fisheries supported by accurate assessment of ecosystem health can help stabilize fish populations and maintain yields essential to feeding a growing population. Moreover, the protection of coastal ecosystems such as mangroves and salt marshes enhances nursery habitats, directly benefiting commercially important species. By ensuring ecosystem resilience, ocean accounting can mitigate the risks associated with environmental variability and anthropogenic pressures.

China’s vision of an “eco-civilization” stresses harmony between human development and nature conservation. The integration of marine ecosystem services into national policy exemplifies this ethos, strengthening the institutional capacity for sustainable ocean governance. Ocean accounting serves not only as a scientific tool but also as a mechanism for societal engagement, enabling stakeholders to visualize and value the natural wealth underpinning their livelihoods. This inclusive approach is critical for fostering collective responsibility and compliance with environmental regulations.

Global leadership in marine sustainability requires innovative frameworks and robust data-driven policies. By pioneering nationwide ocean natural capital accounting, China has the opportunity to set a benchmark for other nations grappling with similar environmental challenges. The development of transparent, province-level reporting systems can catalyze regional cooperation and promote knowledge sharing across jurisdictions. Furthermore, by linking marine ecosystem services to economic and social indicators, China can illustrate a model of sustainable development that reconciles growth with ecological preservation.

Achieving these goals demands interdisciplinary collaboration among scientists, policymakers, and local communities. Ecologists must work alongside economists and social scientists to devise methodologies that capture complex ecosystem dynamics and societal values accurately. Likewise, policymakers need to establish enabling legal frameworks that encourage data sharing, enforce accountability, and provide incentives for conservation efforts. Community engagement is paramount to ensure that management strategies reflect local needs and aspirations, fostering stewardship and compliance.

In summary, the integration of marine ecosystem services and natural capital accounting into China’s environmental governance marks a paradigm shift with far-reaching implications. By harnessing cutting-edge scientific tools and embedding ecological values into economic decision-making, this approach addresses the multifaceted challenges threatening marine sustainability. The resultant frameworks not only underscore the ecological necessity of conservation but also highlight the economic and social imperatives. This holistic strategy holds promise for preserving China’s marine wealth for future generations, while positioning the nation as a global leader in sustainable ocean stewardship.

The future of marine ecosystems in China hinges on recognizing their intrinsic value and ensuring their sustainable use through evidence-based policy and governance. As environmental pressures intensify, the implementation of comprehensive ocean accounting becomes indispensable. This transformative pathway offers a blueprint for reconciling human well-being with ecological integrity and advancing toward a truly sustainable ocean economy.

Subject of Research: Marine ecosystem services and natural capital valuation in China’s coastal and oceanic environments

Article Title: Marine ecosystem services and natural capital in China: Opportunities for improved understanding, valuing, and policy

News Publication Date: 20-May-2025

Image Credits: L. McCook

Keywords: Marine ecology, ecosystem services, natural capital accounting, sustainable ocean governance, China marine ecosystems