The first-of-its-kind study provides a more complete look at the monetary harm caused by global climate damages in the ocean, with implied local impacts.

What will climate damage to the ocean cost us? A lot, potentially, with losses that will “ripple through local economies and communities,” according to the author of a recent study out of La Jolla that measured the economic harm caused by greenhouse gas emissions.

The study from researchers at Scripps Institution of Oceanography at UC San Diego, published Jan 15 in the journal Nature Climate Change, examined ocean damage from climate change, dubbed the “blue” social cost of carbon.

This calculation nearly doubles the global cost of carbon dioxide emissions to society, according to the study, meaning economic losses could impact millions more people than previously thought.

The ocean has largely been left out of computational models used for climate policy, environmental economist Bernardo Bastien-Olvera, who led the study during his postdoctoral fellowship at SIO, told lajolla.ca in an email interview.

“While estimates of climate damages on land grew more sophisticated, ocean science was rapidly documenting how warming, acidification and ecosystem change were transforming marine systems, with little connection between the two,” Bastien-Olvera said.

That oversight “became increasingly hard to ignore,” he added, and led him to seek out SIO scientists “study these systems in depth and to explore how their insights could be translated into policy-relevant economic tools.”

Calculating the cost

State governments and organizations such as the US Environmental Protection Agency and Department of Energy have used the social cost of carbon to measure harm; these calculations are used to determine carbon offsets and inform policy actions to reduce greenhouse gas emissions. 

The ocean variables haven’t had a market value until now, Bastien-Olvera said, and no price tag means invisibility when it comes to decision making.

To account for ocean damage in the economic cost of climate change, the study looked at decreased fisheries revenue or diminished trade, non-market values such as the health impacts of reduced nutrition availability from impacted fisheries and recreational opportunities at the ocean.

The researchers also considered intangibles like humans’ enjoyment of ecosystems and biodiversity, which the researchers call non-use or existence value.

Without ocean impacts included, the social cost of carbon is $51 per ton of carbon dioxide emitted into the atmosphere. When the model is run with ocean impacts, study authors calculated an additional $46.2 per ton of carbon dioxide, reaching $97.2 total per ton of carbon dioxide, a 91% increase.

In 2024, global carbon dioxide emissions were estimated to be 41.6 billion tons, according to the Global Carbon Budget analysis, which would imply trillions of dollars in climate change damages for that year alone. 

The local costs

Locally, there are no San Diego-specific estimates available, Bastien-Olvera said, but the study nonetheless provides a framework for understanding how ocean-related climate costs might affect coastal regions like San Diego.

As the local economy is intertwined with the ocean through its marine ports, which support fisheries and coastal tourism, the climate impacts on fish stocks can translate into disrupted livelihoods and higher prices, Bastien-Olvera said.

Stressed and dwindling ecosystems, like kelp forests and others, also contribute to losses that “ripple through local economies and communities,” he added.

And the intangible component of human enjoyment? 

“The ocean is central to San Diego’s identity and quality of life,” Bastien-Olvera said, with the coastline and beyond shaping “how people experience the city and why they choose to live here. When those systems degrade, the loss is beyond the economy.”

Moving forward

Bastien-Olvera hopes the study will inform updates of the official social cost of carbon estimates, he said, noting that if the costs of ocean damages are left out, “those decisions systematically underestimate the true cost of emissions.”

Further, he said, “this work is meant to open a new line of research,” as the reported numbers are not final and highlight where data is missing, which ecosystems are still invisible and where improved monitoring is necessary.