Impact of Climate Change on Oceans Could Double Previously Estimated Costs
New findings reveal that the financial toll of climate change, particularly on oceans, may have been severely underestimated. A recent study by the University of California San Diego’s Scripps Institution of Oceanography suggests that the global cost of greenhouse gas emissions could be nearly twice as high as previously calculated.
This groundbreaking research introduces a comprehensive analysis of the social cost of carbon (SCC) that, for the first time, includes ocean-related damages. The economic repercussions of coral loss, disruptions in fisheries, and the destruction of coastal infrastructure are projected to amount to nearly $2 trillion each year. This marks a significant shift in how climate-related economic impacts are assessed.
Bernardo Bastien-Olvera, the study’s lead researcher, emphasized, “For decades, we’ve been estimating the economic cost of climate change while effectively assigning a value of zero to the ocean. Ocean loss is not just an environmental issue, but a central part of the economic story of climate change.”
The social cost of carbon is a metric used to estimate the financial impact of emitting one ton of carbon dioxide into the atmosphere. According to Amy Campbell, a United Nations climate advisor, it is “one of the most efficient tools we have for internalizing climate damages into economic decision-making.”
Historically, organizations such as the U.S. Environmental Protection Agency have utilized these calculations to evaluate policy decisions. However, a 2025 White House memo from the Trump administration advised federal agencies to omit this data from their analyses unless legally mandated.
Campbell pointed out the contentious nature of these calculations: “It becomes politically contentious when deciding whose damages are counted, which sectors are included and most importantly how future and retrospective harms are valued.”
When ocean damages are excluded, the social cost of carbon is estimated at $51 per ton of CO2. This figure jumps to $97.20 per ton when ocean impacts are considered, highlighting a 91% cost increase. In 2024, global CO2 emissions were estimated at 41.6 billion tons, underscoring the significance of this recalculation.
The study predicts annual damages to traditional markets will reach $1.66 trillion by 2100, based on projected greenhouse gas emissions. Scientists from diverse fields contributed to this research, assessing the costs across four sectors: corals, mangroves, fisheries, and seaports. Their analysis included direct market losses as well as non-market values, such as the cultural and ecological significance of marine ecosystems.
“Something has value because it makes the world feel more livable, meaningful, or worth protecting, even if we never directly use it,” Bastien-Olvera noted, highlighting the intangible benefits of ecosystems that are often overlooked in economic evaluations.
The study also indicates that island nations, dependent on seafood, will bear the brunt of ocean warming and acidification. Kate Ricke, co-author and climate professor at UCSD, stated, “The countries that have 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.” This inclusion of ocean data in SCC assessments points to increased health risks in low-income countries due to nutritional deficiencies.
Despite the daunting findings, Bastien-Olvera and Ricke remain hopeful that this research will drive policy changes. Ricke commented, “I hope that the high value of ‘blueSCC’ can motivate further investment in adaptation and resilience for ocean systems,” referring to potential opportunities in coral reef and mangrove restoration.
Bastien-Olvera added that recognizing the economic value of oceans also honors the conservation efforts of coastal communities and Indigenous peoples. “For a long time, climate economics treated the ocean values as if it were worth zero,” he said. “This is a first step toward finally acknowledging how wrong that was.”
Original Story at insideclimatenews.org