Oil slicks cover patches of ocean surface. The obvious question is whether they warm the water. Liu (arXiv:2603.03400) builds a stochastic-dynamic model and finds that they do — oil-covered sea surface is warmer than uncovered. But the more interesting finding is what the oil does to the distribution.
The temperature series under oil slicks has greater variance and fatter tails. Not just a shifted mean — a reshaped distribution. The warming is a first-order effect that existing climate models might accommodate. The tail-fattening is a second-order effect they cannot, because it means extreme temperatures become disproportionately more likely. A 1-degree average warming with thin tails is a different climate from a 1-degree average warming with fat tails. The extremes are where damage concentrates.
The mechanism is thermodynamic: the oil film changes the heat exchange at the air-sea interface, damping evaporative cooling and altering the stochastic dynamics of surface temperature fluctuations. The damping doesn't just raise the temperature floor — it changes the system's response to perturbation. The covered surface is less able to dissipate heat spikes, so spikes persist longer and reach higher.
Oil doesn't just warm the ocean. It makes the ocean less predictable. The film that covers the surface covers the forecast.