Putting a Price on Ocean Damage in Climate Economics
Why the ocean is changing the climate cost conversation
A study by researchers at the University of California San Diego’s Scripps Institution of Oceanography argues that the global economic cost of greenhouse gas emissions is nearly double what scientists previously thought. The change comes from a major shift in what is counted: for the first time in this type of assessment, damages to the ocean are included in the calculation of the social cost of carbon (SCC).
The SCC is a way of translating climate harm into a dollar figure. It estimates the monetary cost of each ton of carbon dioxide released into the atmosphere. In practical terms, it is used as an accounting tool in policy and economic decision-making, helping governments and institutions weigh the costs and benefits of actions that increase or reduce emissions.
Researchers involved in the new work say that past approaches effectively treated the ocean as if it had no economic value in this framework. Bernardo Bastien-Olvera, who led the study during his postdoctoral fellowship at Scripps, summarized the issue by arguing that decades of estimates assigned “a value of zero to the ocean,” even though ocean loss is not only an environmental concern but also a central part of the economic story of climate change.
What the social cost of carbon measures—and why it matters
The social cost of carbon is designed to capture economic harm from emissions in a standardized way. Amy Campbell, a United Nations climate advisor and former British government COP negotiator, described it as one of the most efficient tools available for internalizing climate damages into economic decision-making. That framing points to how SCC values can influence the evaluation of policies, regulations, and investments.
Historically, SCC calculations have been used by international organizations and by state departments such as the U.S. Environmental Protection Agency to assess policy proposals. At the same time, Campbell noted that the SCC becomes politically contentious, because debates can arise over which damages are counted, which sectors are included, and how harms—both future and retrospective—are valued.
The study’s central claim is that excluding ocean harm has left a large portion of climate damages out of the economic picture. Because the ocean covers about 70 percent of the planet, the authors argue that a climate cost metric that does not account for ocean impacts is incomplete.
How much the estimated cost changes when ocean damages are included
One of the study’s most striking results is the scale of the difference between SCC estimates with and without ocean impacts. The research states that, excluding ocean harm, the social cost of carbon is $51 per ton of carbon dioxide emitted. When ocean damages are included, the estimate rises to $97.20 per ton.
That change—an increase of 91 percent—is presented as significant in part because of the volume of global emissions. The study notes that global CO2 emissions in 2024 were estimated to be 41.6 billion tons. Even small changes in the per-ton estimate can therefore translate into very large changes in the implied global cost of emissions.
Beyond the per-ton metric, the study also provides a long-range estimate of the scale of economic harm. Using greenhouse gas emission predictions, it estimates that annual damages to traditional markets alone will be $1.66 trillion by 2100. The study also highlights that global coral loss, fisheries disruption, and coastal infrastructure destruction are estimated to cost nearly $2 trillion annually, a figure used to illustrate how ocean impacts can fundamentally change how climate finance is measured.
What “ocean damages” includes in the new assessment
The study began in 2021 and brought together scientists from multiple disciplines, including fisheries experts, coral reef researchers, biologists, and climate economists. The team assessed downstream climate change costs across four key sectors:
- Corals
- Mangroves
- Fisheries
- Seaports
These categories reflect both ecological systems and economic infrastructure. The assessment measures impacts ranging from market losses—such as reduced fisheries output and disruptions to marine trade—to reductions in ocean-based recreational industries. In other words, the study is not limited to one type of cost; it attempts to capture multiple ways in which ocean change can affect economies.
By structuring the analysis around these sectors, the authors aim to show that ocean-related climate harm is not an abstract concept. It can be tied to specific systems that support food, livelihoods, transport, and coastal activity.
Market losses and the role of “traditional” economic measures
Some of the damages described in the study fall into what economists typically consider market impacts—losses that can be tracked through prices, output, and revenue. Examples mentioned include reduced fisheries and disruptions to marine trade, as well as the destruction of coastal infrastructure such as seaports.
The study’s estimate that annual damages to traditional markets alone will be $1.66 trillion by 2100 is presented as a way to quantify these kinds of costs. While the details of how each component contributes are not fully laid out in the extracted material, the overall message is that ocean-related market losses are large enough to materially change SCC calculations.
In this framing, the ocean is not only a backdrop to climate change. It is an economic system with assets, services, and infrastructure that can be damaged by warming and acidification, with measurable consequences for trade and food systems.
Non-use values: pricing what people value even if they never “use” it
The study also places a monetary figure on what economists call non-use values. These are values that do not depend on direct consumption or visitation. Bastien-Olvera described the idea this way: something can have value because it makes the world feel more livable, meaningful, or worth protecting, even if people never directly use it.
He offered examples to illustrate the point, noting that most people will never visit a coral reef during a full-moon spawning event or see a deep-sea jellyfish glowing in total darkness. Yet many still care that these things exist. In the study’s framing, that concern can be considered part of the overall cost of climate damage, even if it does not show up in conventional market transactions.
Including non-use values expands the SCC beyond a narrow set of economic indicators. It also raises difficult questions about valuation, because it requires translating cultural and ecological loss into monetary terms. The authors present this as a necessary step to avoid treating the ocean as economically irrelevant.
Who bears the costs: island economies and low-income countries
The study argues that the impacts of ocean warming and acidification will not be evenly distributed. It states that island economies, which rely more on seafood for nutrition, will face disproportionate financial and health impacts. This is not only about economic output; it is also about nutrition and well-being.
Kate Ricke, a co-author and climate professor at UCSD’s School of Global Policy and Strategy, emphasized a broader equity issue: the countries with the most responsibility for causing climate change and the most capacity to fix it are not generally the same countries that will experience the largest or most near-term damages.
Including ocean data in SCC assessments, the study suggests, reveals increased consequences for morbidity and mortality in low-income countries facing increased nutrition deficiency. In this sense, the ocean component of SCC is not only a technical adjustment. It changes how climate harm is distributed in the accounting, bringing certain vulnerabilities into sharper focus.
Policy relevance and political contention
The SCC is often discussed as a technical tool, but the extracted material underscores that it is also politically sensitive. Campbell’s comments highlight why: decisions about what to count, which sectors to include, and how to value future harms can have major implications for policy outcomes.
The content also notes that a 2025 White House memo from the Trump administration instructed federal agencies to ignore SCC data during cost-benefit analyses unless required by law. That detail is presented as an example of how SCC can become entangled in political debates over regulatory approaches and the role of climate costs in government decision-making.
In that context, the study’s “blueSCC” framing—an ocean-based social cost of carbon—can be seen as both a scientific adjustment and a potential policy flashpoint. If the per-ton cost of emissions rises substantially when ocean damages are included, then the implied economic justification for emissions reductions may also change.
Adaptation and resilience: what the researchers hope comes next
Despite the scale of the damages described, the researchers express optimism that the data could influence international decision-making. Ricke said she hopes the high value of “blueSCC” can motivate further investment in adaptation and resilience for ocean systems. She referenced opportunities to invest in coral reef and mangrove restoration projects.
In this framing, putting a higher cost on emissions is not only about assigning blame or tallying losses. It is also about clarifying the economic rationale for protecting and strengthening ocean systems that support communities and livelihoods.
The study’s sector focus—corals, mangroves, fisheries, and seaports—also points to where adaptation and resilience conversations might concentrate, because these are the areas where damages were explicitly assessed.
Recognizing long-standing ocean stewardship
Bastien-Olvera also argued that centering the framework on oceans recognizes the longstanding conservation approaches of coastal communities, ocean scientists, and Indigenous peoples. His remarks frame the study as a “first step” toward acknowledging that treating ocean values as zero was wrong.
While the extracted material does not provide detailed examples of specific stewardship practices, the point is presented as a matter of recognition: that many communities have long treated ocean ecosystems as valuable and worth protecting, even when economic models did not reflect that value.
In that sense, the study is positioned not only as a scientific and economic update, but also as a reframing of what counts in climate damage assessments.
What changes when the ocean is included in climate cost estimates
The overall implication of the research is that climate cost estimates can shift dramatically when ocean damages are included. Moving from $51 per ton of carbon dioxide to $97.20 per ton changes the scale of the economic harm associated with emissions. With global emissions estimated at 41.6 billion tons in 2024, the difference becomes consequential for how societies understand the stakes.
At the same time, the study’s approach highlights how the ocean intersects with multiple dimensions of climate risk:
Ecological loss through coral and mangrove damage
Food and livelihoods through fisheries disruption
Trade and infrastructure through impacts on seaports and coastal systems
Human well-being through nutrition-related health consequences in vulnerable regions
Cultural and existence value through non-use values tied to ecosystems and biodiversity
By combining market impacts with non-use values, the assessment broadens what is counted as climate damage. The researchers argue that this broader accounting is necessary to avoid underestimating the true cost of greenhouse gas emissions.
A recalibration of climate economics
The study’s findings suggest a recalibration in how climate economics can be conducted. If the ocean is treated as central rather than peripheral, then the SCC becomes a different measure—one that reflects the scale of losses tied to a system covering most of the planet.
Whether and how policymakers adopt such updated values can depend on political choices as well as scientific ones. Still, the work presented here makes a clear claim: leaving ocean damages out of the social cost of carbon has led to a substantial undercount of climate harm, and incorporating those damages changes the economic story of climate change in a measurable way.