Florida’s barrier reef is in trouble – and it’s costing us.
The reef has been experiencing a severe outbreak of stony coral tissue loss disease over the past decade. The likely cause: stress from the warming climate and acidifying waters, both the result of burning fossil fuels.
The financial stake of losing the reef is high. Florida’s coral reefs are estimated to draw in over $1 billion in tourism revenue each year, provide $650 million in flood protection benefits, and support over 70,000 jobs. What’s more, coral reefs protect people and property by dissipating up to 97% of wave energy, lessening storm surges.
A new study in Nature Climate Change looks at such costs worldwide, estimating the total price of climate-change-related damage to the world’s oceans. The study concludes that accounting for ocean impacts nearly doubles the estimated climate costs to society, known as the social cost of carbon.
But as with most climate impacts, these costs are unequally borne, most heavily by people in poorer island nations and in other coastal regions like Florida. And as with all climate threats, they are being wholly ignored by the Trump administration.
‘A missing piece’
Earth’s oceans play a critical and often overlooked role in the health and well-being of people and cultures around the world. The average person consumes nearly one pound of seafood per week, which provides important dietary nutrients. Coastal ecosystems like mangrove forests and coral reefs also protect coastal communities against storm surges, a growing threat as a result of rising sea levels and climate-intensified storms.
But these benefits, which are threatened by climate change, are difficult to quantify. And when they’re not quantified, they’re left out of experts’ estimates of the damages we incur by burning fossil fuels and releasing climate-warming carbon dioxide – the social cost of carbon.
As a result, even when the U.S. Environmental Protection Agency updated the federal estimate of the social cost of carbon in 2023 to nearly four times its previous value, the agency noted that this was likely still an “underestimate [of] the damages associated with increased climate risk.”
Climate impacts in the oceans in particular have been “a big missing piece recognized by every major assessment” of the social cost of carbon, said Bernie Bastien-Olvera, a climate scientist at the National Autonomous University of Mexico, in an email. He is the lead author of the new Nature Climate Change study.
Climate change’s one-two ocean punch
Human burning of fossil fuels affects Earth’s oceans via the one-two punch of warming and acidifying waters, which occurs as carbon dioxide is absorbed into the ocean. The oceans are about 40% more acidic today than they were before the Industrial Revolution.
Left: 1850–2025 global average sea surface temperature. (Data: UK Met Office Hadley Centre. Graphic: Dana Nuccitelli); Right: 1985–2024 global average surface seawater pH. (Data: EU Copernicus Marine Service. Graphic: Dana Nuccitelli)
The falling pH of the oceans makes it more difficult for certain marine species, like shellfish and coral, to build their shells or skeletons. As a result of this combination of changing pH and heat, there have been four global mass coral bleaching events since 1998. These events indicate extreme stress and life-threatening conditions for coral reefs, upon which approximately one-quarter of all marine life relies for food, shelter, and breeding grounds.
Read: How climate change is making hurricanes more dangerous
Island nations ‘disproportionately threatened’
The new study found that island nations, whose very existence is often threatened by rising sea levels, are “disproportionately affected” by the impacts of climate change on the oceans.
For example, about one-third of the world’s tuna catch comes from a group of 14 Pacific island nations. Fees associated with tuna fishing access account for about one-third of their government revenue, tuna fishing supports tens of thousands of jobs in the region, and tuna are an important dietary staple in these cultures.
But a 2021 study led by Conservation International’s Senior Director of Tuna Fisheries Johann Bell estimated that as warming oceans cause tuna to migrate away from this region, catches could be reduced by as much as 20% by 2050. Some Pacific Island coastal communities already “have trouble catching enough coral reef fish for food security,” Bell wrote via email. That’s the result of a combination of ocean warming and acidification, as well as human population growth.
The new Nature Climate Change study found that the loss of omega-3 fatty acids, calcium, iron, and protein from seafood-depleted diets would have significant negative effects on the health of populations that rely on these dietary sources. For example, the authors note that “a full intake of omega-3 fatty acids reduces risk of cardiovascular diseases by 7% relative to a diet poor of omega-3 fatty acids.”
Overall, these health impacts account for about half the study’s new estimated social cost of carbon from ocean impacts. Most of the rest stems from the loss of corals and mangroves, and the benefits they provide in terms of protecting coastal communities like Florida’s from increasingly severe storm surges, for example.
The Trump EPA buries its head in the eroding sand
Despite the ever-improving understanding of the immense damages associated with unabated climate change, the EPA in 2026 has strayed even further from evidence-based reality.
Although federal agencies are required by law to consider the costs and benefits of proposed regulations, the Trump EPA reportedly plans to stop assessing gains resulting from the health benefits of its air pollution rules. And the agency continues to move forward with its efforts to dismantle federal climate pollution regulations altogether, effectively treating the social cost of carbon as $0, compared to the nearly $400 per ton that would result from the combination of the EPA’s 2023 estimate and the new study’s estimated ocean damage costs to society.
Read: Trump just torched the basis for federal climate regulations. Here’s what it means.
But the new research still offers important value and insights.
“The way I see it, there are many other countries in the world (or even state/local governments within the U.S.) that can benefit from having better estimates of the social cost of carbon that rely on our best science and economics recognizing the oceans,” Bastien-Olvera said.
And a future administration and EPA could potentially reintroduce climate regulations and pollution cost-benefit analyses. Accounting for a nearly doubled social cost of carbon pollution could justify more stringent future climate rules.
“I hope that this metric proves useful for future U.S. governments,” Bastien-Olvera said.
The fate of island nations and Florida’s coastline alike may depend on it.
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