Most new oil and gas projects in 2024 were located offshore, where spills can be hard to detect. Researchers at the nonprofit SkyTruth recently published a report identifying the biggest sources of pollution from offshore oil, including oil leaks, transportation emissions and methane flaring, as well as the most polluted locations.
Christian Thomas, a geospatial engineer at SkyTruth who worked on the report, told Mongabay that before now, “there hasn’t been an accounting really of the full impacts [from] the global offshore oil and gas industry.”
To understand the impacts, the researchers looked at both fixed oil production infrastructure and floating production and storage vessels (FxOs) — newer, more modular ways to extract and transport ocean oil.
Using satellite data from June 2023 to October 2024, researchers identified the most polluting facilities by calculating the frequency and extent of observable oil slicks associated with them.
Globally, there are more than 24,000 fixed structures and only approximately 300 FxOs, yet SkyTruth found that four of the top 10 most polluting facilities are FxOs.
The most polluting FxO lies in Nigeria, where the researchers observed “oil slicks in 18% of all satellite images, suggesting it may release oil every five days on average.”
Nigeria is home to five of the top 10 most polluting offshore facilities, the report found. As Mongabay has previously reported, Nigerian regulatory agencies rely on the oil industry to self-report spills. Environmentalists told Mongabay that spills could grow as international oil majors sell aging offshore facilities to local companies, many not as equipped to safely operate them.
The researchers also used data from the University of California, Santa Barbara’s Marine Biotechnology Lab to model the transportation emissions from ships traveling to and from offshore oil facilities. They found that in 2023, roughly 9 million metric tons of emissions were produced from transportation — that’s more than the emissions individually produced by 95 countries and roughly the same as Paraguay.
An oil import terminal in California, U.S., had the most transportation emissions, with 516 vessel visits in 2023.
Furthermore, using satellite data researchers found that in 2023, offshore oil and gas facilities burned roughly 23 billion cubic meters (812 billion cubic feet) of natural gas, mostly unwanted methane released during oil and gas production. Methane flaring created approximately 60 million metric tons of carbon dioxide; the largest sources were linked to infrastructure in Iran, Nigeria and Mexico.
Thomas said most of their figures are likely underestimates — for some areas, satellites only pass by to detect oil spills and methane flares every 12 days or so and vessels may not report all their voyages.
Thomas said he hopes this report will give governments and communities valuable information that will “allow them to better focus their enforcement efforts and ensure that marine ecosystems and coastal communities are better protected.”
Banner image: of a turtle following the Deepwater Horizon oil spill. Courtesy of NOAA and the Georgia Department of Natural Resources.