OCEAN: The True Cost of Carbon Emissions & more – 20th Jan 2026

Ahoy from BA! This is the Rorshok Ocean Update from the 20th of January twenty twenty-six. A summary of what's going down in the 70% surface of the Earth covered in saltwater.

We start this week with an alarming update that carries major implications for climate policy.

A study published this week in the journal Nature shows that the economic impact of climate change has been significantly underestimated because it fails to fully account for damage to the ocean. The Social Cost of Carbon, which estimates the monetary harm caused by emitting one additional metric ton of carbon dioxide, sits at the center of this finding.

Researchers found that when ocean impacts such as coral reef loss, declining fisheries, ocean warming, and reduced coastal protection are included, the true cost of carbon emissions nearly doubles. The authors of the study warn that most government models still overlook these damages, leading to carbon prices that underestimate real harm and slow effective climate action. Because these models shape climate laws, taxes, and investment decisions, ignoring ocean damage has wide-reaching consequences.

Fortunately, there are signs of progress in global ocean governance.

On Saturday the 17th, the United Nations High Seas Treaty officially entered into force, establishing the first legally binding framework to protect marine life in international waters.

Under the agreement, countries can designate marine protected areas on the high seas and are required to carry out environmental impact assessments for activities that could cause significant harm. Supporters describe the treaty as a historic breakthrough, though many caution that its success will depend on effective enforcement and long-term funding. Environmental groups note that more than one hundred ninety thousand protected areas would be needed to meet the goal of protecting thirty percent of the ocean by twenty thirty. Today, only about eight percent of the ocean is formally protected.

On a related note, in an opinion essay published this week in Oceanographic Magazine, marine conservation expert Callum Roberts reflects on why the High Seas Treaty offers a rare moment of hope for ocean protection, but only if it is properly enforced.

He argues that while the treaty creates a long-awaited legal framework to protect biodiversity beyond national waters, its success will depend on whether governments commit real resources to monitoring, enforcement, and compliance. Without those measures, Roberts warns that marine protected areas on the high seas could exist only on paper.

To read the full essay, check out the link in the show notes.

Staying with ocean governance, a new report points to growing security challenges at sea.

The International Maritime Bureau reported a sharp rise in piracy and armed robbery incidents worldwide last year. While many cases involved low-level theft, the bureau warned that even minor attacks reveal gaps in maritime surveillance and enforcement, particularly in busy or poorly monitored waters.

Not all threats to the ocean originate offshore, though.

This week in Ghana, authorities intensified raids against illegal gold mining, known locally as galamsey, along the Ankobra River in the Western Region. Environmental groups warn that polluted rivers carry mercury-laden sediments into estuaries and coastal waters, threatening fisheries and mangroves.

Officials say enforcement is ongoing, but acknowledge that environmental damage remains severe and long-lasting.

Meanwhile, shipping has faced a significant climate policy shift this week.

From the beginning of January twenty twenty-six, the EU expanded its emissions trading system for maritime transport to cover methane and nitrous oxide, alongside carbon dioxide. The move marks a significant tightening of climate rules for shipping, targeting gases that have far greater short-term warming effects than CO₂.

Supporters say the expansion increases pressure on shipping companies to address their full climate footprint rather than focusing narrowly on carbon emissions. Industry groups, however, warn that the changes could raise costs and require major operational adjustments. The decision reflects growing political momentum in Europe to regulate shipping emissions more aggressively as part of its broader climate strategy.

In updates from beneath the ocean’s surface…

Scientists this week reported new findings from Antarctica led by scientists from the British Antarctic Survey and the University of Southampton, working with international partners studying the Southern Ocean. The team identified massive turbidity currents, sometimes described as underwater tsunamis, racing down continental slopes beneath the sea.

These powerful flows carry cold, dense water and large volumes of sediment at high speed. Researchers say the currents are increasingly triggered by iceberg calving, the process by which large chunks of ice break off glaciers and ice shelves and enter the ocean. As this happens, the currents redistribute heat, nutrients, and carbon through the Southern Ocean and can accelerate the melting of ice shelves from below.

Understanding these processes could improve climate and sea level rise models.

From the frozen south to tropical waters, as there is cautious optimism for coral reefs.

This week, researchers in Mauritius reported strong results from a coral restoration project focused on breeding and replanting heat-resistant corals. During recent marine heatwaves, the restored corals showed survival rates close to one hundred percent, while nearby reefs suffered severe bleaching.

Scientists stress that restoration cannot replace cutting greenhouse gas emissions. But they say targeted projects may help reefs recover faster and protect ecosystems that support fisheries, tourism, and coastal communities.

Even with restoration efforts, pressure on ocean life remains intense.

On Wednesday the 14th, United States regulators closed the General Category commercial Atlantic bluefin tuna fishery after reported landings exceeded the quota for the entire January to March period just two weeks into the year. The National Oceanic and Atmospheric Administration announced the closure, which took effect late that evening.

Atlantic bluefin tuna are among the world’s most valuable fish species, with individual catches sometimes worth tens of thousands of dollars. Regulators say early closures are necessary to prevent overfishing and protect long-term stock health, particularly as global demand for bluefin tuna continues to rise and fishing pressure intensifies.

Speaking of environmental pressure on the ocean, marine scientists are warning of a major ecological shift.

On Monday the 19th, researchers reported that floating seaweed, particularly sargassum, is spreading across the world’s oceans at an accelerating pace.

Using AI to analyze more than one million satellite images collected over the past two decades, scientists found that large seaweed mats have increased by roughly thirteen percent per year. The fastest expansion has occurred in the tropical Atlantic and parts of the Pacific.

The researchers say warming ocean temperatures and excess nutrients from agricultural runoff are fueling the growth. They warn that these blooms can block sunlight, alter water chemistry, disrupt fisheries, and damage coral reefs, signaling what they describe as a potential regime shift in ocean ecosystems.

From ecosystem change to species protection, as this week scientists unveiled a new global tool for ocean conservation.

On Wednesday the 14th, researchers from the International Union for Conservation of Nature released the world’s first global map of Important Shark and Ray Areas. The IUCN Shark Specialist Group led the project and involved more than 300 scientists from over fifty countries. Together, they identified more than seven hundred fifty regions critical for shark and ray feeding, breeding, and migration.

Sharks and rays are among the most threatened marine species worldwide. Researchers say the map provides governments with a science-based tool to guide marine protected areas and fisheries management, both within national waters and across the high seas.

Let’s finish off this episode with a step into the unknown

On Wednesday, the 14th, a team of forty-six marine scientists aboard the UK research vessel RRS James Cook launched a major deep-sea exploration project in the Caribbean known as Beyond the Reef. The expedition is part of the UK Government’s Blue Belt program, which supports scientific research and conservation in and around the waters of Caribbean islands.

The goal of Beyond the Reef is to chart large, previously unmapped areas of the seafloor. Researchers say better maps are essential for managing fisheries, protecting deep-sea biodiversity beyond coral reefs, and making informed decisions about future ocean use. Much of the data collected will be made publicly available to support science and conservation efforts.

Aaand that’s it for this week! Thank you for joining us!

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See you next week!