In the vast, blue expanse of our planet’s oceans, an extraordinary mechanism quietly operates, securing colossal amounts of carbon away from the atmosphere and thus playing an essential role in regulating Earth’s climate. This process, known as the biological carbon pump (BCP), is emerging as a cornerstone for climate mitigation, yet until now, its wider significance in the spheres of conservation, climate finance, and international policymaking has been vastly underestimated. In a groundbreaking new study published in Nature Climate Change, researchers have mapped, measured, and monetized the global distribution and impact of the BCP—offering a fresh and urgent perspective on its value to humanity and the planet.
The biological carbon pump encompasses the myriad processes through which phytoplankton and other marine organisms capture atmospheric carbon dioxide via photosynthesis, incorporating it into organic matter that then sinks to the ocean’s depths, effectively sequestering carbon for decades or even centuries. Despite its recognized role in carbon cycling, prior assessments have struggled to quantify or economically evaluate its true magnitude on a global scale. Berzaghi, Pinti, Aumont, and their colleagues painstakingly bridged this gap by using sophisticated spatial analyses combined with financial valuation techniques, providing a comprehensive picture that underscores why the BCP deserves central attention in climate conversations.
Their research reveals that every year, the BCP transfers approximately 2.81 gigatons of carbon (GtC) into the ocean’s interior, with this figure fluctuating between 2.44 and 3.53 GtC depending on regional and temporal variabilities. This carbon stock is not transient—it remains sequestered for a minimum of 50 years, with estimates allowing for an uncertainty margin of plus or minus 25 years. The longevity of sequestration is critical because it means the BCP directly offsets atmospheric carbon concentrations over multidecadal timescales, effectively buying humanity essential time to transition toward a sustainable future.
What sets this study apart is its groundbreaking effort to translate the biological carbon pump’s carbon capture function into economic terms. By applying rigorous valuation models grounded in the social cost of carbon, the researchers estimated that the BCP’s service equates to a staggering US$545 billion annually in areas beyond national jurisdiction—those vast oceanic regions outside any one nation’s exclusive economic zone (EEZ). Within EEZs, which span the marine territories of individual countries, the valuation stands at an impressive US$383 billion per year. Summed and discounted over the seven-year period from 2023 through 2030, the total economic worth of this natural carbon fixation mechanism surpasses US$2.2 trillion globally.
This colossal figure not only highlights the BCP’s fundamental ecological value but also positions it as a pivotal asset for financial markets and climate policy instruments. Large ocean states—nations with expansive EEZs—emerge as de facto custodians of a critical piece of the planet’s carbon budget, conferring upon them both a responsibility and an opportunity to leverage their marine stewardship in climate mitigation strategies. As the international community gears up for pivotal discussions at the next Conference of the Parties (COP) global stocktake, the inclusion of marine carbon sequestration mechanisms like the BCP could dramatically reshape targets and funding allocations.
The methodology behind these novel valuations is anchored in an interdisciplinary approach combining oceanographic data, climate modeling, and economic analysis. Using global ocean biogeochemical models, the scientists tracked phytoplankton productivity, sinking particle fluxes, and remineralization rates—the key components of the biological carbon pump—at fine spatial and temporal resolutions. Overlaying these ecological outputs with economic models that factor in the projected social costs of carbon allowed the team to assign a monetary value to the BCP across different marine jurisdictions. This approach represents a methodological leap in ecosystem service valuation, specifically tailored to the ocean realm, which has conventionally resisted such integration due to its complexity and global extent.
The findings stress that the BCP is not a static service but rather a dynamic, globally interconnected phenomenon influenced by regional oceanographic conditions and climatic changes. For instance, nutrient availability, temperature regimes, and biological community structures in various parts of the oceans modulate the intensity of carbon export to the deep sea. This spatial heterogeneity underlines the necessity of region-specific conservation policies and scientific monitoring to safeguard and optimize the BCP’s performance amid accelerating climate impacts on marine ecosystems.
Furthermore, the study’s implications extend into the arena of blue finance—a rapidly growing sector seeking to channel investment into ocean conservation and sustainable use. Recognizing the BCP as a quantifiable and monetizable ecosystem service opens doors for novel financial products, green bonds, and carbon credit markets that incorporate marine carbon sequestration. Such instruments could incentivize nations and private stakeholders to invest directly in protecting ocean health, enhancing phytoplankton productivity, or mitigating marine pollution—actions that, in turn, strengthen the biological carbon pump.
From a policy perspective, these empirical and economic insights lend substantive weight to arguments for integrating oceanic carbon sequestration into national greenhouse gas inventories, international carbon accounting frameworks, and climate conventions. Discussions around the post-2025 carbon markets and the design of the Paris Agreement’s enhanced transparency framework may benefit from recognizing ocean processes alongside terrestrial sinks like forests and soils. Indeed, incorporating the BCP in climate commitments could unlock transformative pathways for nations to meet or exceed emission reduction targets.
The role of remote sensing and advanced ocean monitoring technologies is also central to advancing our understanding of the BCP’s variability and response to anthropogenic pressures. Satellites, autonomous floats, and undersea observatories provide real-time data on chlorophyll concentrations, particle flux, and export efficiency—parameters essential for refining estimates of carbon sequestration and verifying climate finance flows. Continued investment in these technological capacities will be indispensable for operationalizing the BCP as a reliable and transparent climate mitigation tool.
Yet, the research by Berzaghi and colleagues also cautions against complacency; the biological carbon pump is intrinsically tied to marine ecosystem health, which faces threats from overfishing, acidification, warming, and pollution. Disruptions to phytoplankton communities or changes in food web dynamics could diminish the pump’s effectiveness, triggering a feedback loop exacerbating climate change. Hence, maintaining the resilience and productivity of marine ecosystems is a prerequisite for harnessing the BCP’s full climate potential.
This pioneering study therefore sets a new agenda—one that bridges oceanography, economics, and policy—to more fully integrate the oceans into global climate action. By quantifying and valuing the biological carbon pump, it not only elevates ocean health to the forefront of climate solution strategies but also emboldens calls for comprehensive stewardship that recognizes the oceans’ indispensable role in the planetary carbon cycle. As policymakers deliberate future commitments and financial mechanisms, acknowledging the biological carbon pump could become a defining factor in the efficacy and ambition of global climate initiatives.
In essence, the oceans—the planet’s largest carbon sink—have been undervalued assets in climate mitigation discussions. This research not only corrects that oversight but also reveals the biological carbon pump as a trillion-dollar ecosystem service that merits active protection, scientific attention, and integration into the world’s climate policy frameworks. The magnitude of its carbon capture and the economic valuation provided demand a paradigm shift in how governments, financial institutions, and international bodies conceive of marine conservation and climate responsibility.
As nations prepare for future climate negotiations and stocktakes, the biological carbon pump stands as a beacon of nature-based solutions with measurable, long-term impacts. Recognizing and funding its preservation could catalyze new momentum toward achieving global carbon neutrality goals while reinforcing the symbiotic relationship between ocean health and humanity’s future. The work by Berzaghi and collaborators is a clarion call to action that the oceans—once regarded as passive backdrops in climate discourse—are dynamic, invaluable partners in our fight against climate change.
Subject of Research: Global quantification, distribution, and economic valuation of the biological carbon pump in the ocean.
Article Title: Global distribution, quantification and valuation of the biological carbon pump.
Article References:
Berzaghi, F., Pinti, J., Aumont, O. et al. Global distribution, quantification and valuation of the biological carbon pump. Nat. Clim. Chang. 15, 385–392 (2025). https://doi.org/10.1038/s41558-025-02295-0
Image Credits: AI Generated
