The global cost of greenhouse gas emissions is nearly double previous estimates, according to a study published Thursday by researchers at the University of California, San Diego's Scripps Institution of Oceanography. The study, which factors in damages to the ocean for the first time in a social cost of carbon (SCC) assessment, estimates that global coral loss, fisheries disruption, and coastal infrastructure destruction cost nearly $2 trillion annually.

The inclusion of ocean damage in the SCC assessment fundamentally changes how climate finance is measured. The social cost of carbon is an accounting method used to determine the monetary cost of each ton of carbon dioxide released into the atmosphere. This metric is crucial for policymakers and businesses in evaluating the economic impact of climate change and informing decisions related to emissions reductions and climate adaptation strategies.

"For decades, we've been estimating the economic cost of climate change while effectively assigning a value of zero to the ocean," said Bernardo Bastien-Olvera, who led the study during his postdoctoral fellowship at Scripps. "Ocean loss is not just an environmental issue, but a central part of the economic story of climate change."

The $2 trillion annual cost attributed to ocean damage encompasses a range of economic impacts. Coral reef degradation, for example, affects tourism revenue, fisheries, and coastal protection. Disruptions to fisheries impact the livelihoods of millions of people and the global seafood market. Coastal infrastructure damage from rising sea levels and more intense storms necessitates costly repairs and replacements.

The revised SCC, incorporating ocean damages, is expected to have significant implications for carbon pricing policies, investment decisions, and corporate sustainability strategies. Companies in sectors such as shipping, tourism, and fishing, which are heavily reliant on healthy ocean ecosystems, may face increased pressure to reduce their carbon footprint and invest in ocean conservation efforts. Governments may also be prompted to implement stricter regulations on emissions and allocate more resources to coastal protection and marine conservation.

The study highlights the interconnectedness of climate change and ocean health, emphasizing the need for a more holistic approach to climate finance. By assigning a monetary value to ocean damages, the research provides a stronger economic justification for investing in climate mitigation and adaptation measures that protect marine ecosystems. The findings are expected to inform future climate negotiations and policy decisions at both the national and international levels.