WHAT ARE THE ODDS? EXTREME VALUE THEORY INDICATES THERE IS A 30% CHANCE OF A CATASTROPHIC OIL SPILL IN THE GULF OF MEXICO BEFORE 2050

The Bureau of Ocean Energy Management (BOEM) calculates risk = frequency x consequence, where frequency is the number of expected spills over a given amount of exposure, and exposure is often measured in billions of barrels of oil that may be produced. BOEM considers spills which have an expected frequency of >1, or a >63% chance of occurrence under a Poisson distribution, as statistically expected. The most recent Gulf of Mexico (GOM) catastrophic discharge event (CDE) (>159,000 m³) risk analysis from BOEM maps possible trajectories of oil released in a CDE but does not include any estimates of the expected frequency or probability of a CDE, which BOEM has described as “low probability” and “unlikely” in recent proposed oil and gas development environmental impact statements. BOEM estimates that the return period for CDEs for the United States outer continental shelf is 165 years based on an extreme value theory (EVT) model fitted to 49 years of annual maximum spill data from 1964-2012. Using only GOM spills from 1964-2024, I refit the model to 61 oil production volume blocks (60,678,000 m³) instead of annual blocks. The return period for CDEs in the GOM was 107 production volume blocks. The estimated oil production in the GOM from 2025-2050 is 2.37 billion m³ (39 production volume blocks). With that level of oil production, the probability of an oil spill >159,000 m³ is 30%, and at least one spill >43,826 m³ (95% CI: 9,920 to 193,622 m³) would be expected.

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Primary Presenter: Susan Lubetkin, Elemental Statistics (susan.c.lubetkin@gmail.com)

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Susan Lubetkin, Elemental Statistics  (susan.c.lubetkin@gmail.com)