Carol Browner, Energy and Climate Change Policy Assistant is out in the media today (August 4, 2010) claiming three quarters of the oil spill has vanished. Good news indeed for the President on his birthday — if it is a fact. On the other hand, sceptics might be wary of the claim given the history of the spill. The leak was first claimed to be 1000 barrels per day and later judged to be closer to 100,000 bpd. It continued spewing the oil out at this unprecedented rate until BP was able to start siphoning some of the leak many weeks later. The original estimate was so far off the actual figure (a hundred times) it voids further claims unless proven methodology can verify them. In actual fact, assessments of the quantity of oil remaining have always been notoriously difficult. The current estimates of oil leaked in the Gulf are between four to five million barrels — for comparison consider the 260,000 barrels spilled in the Exxon Valdez disaster or the 8,000 barrels released in Guanabara Bay near Rio de Janeiro ten years ago.
The impression Ms. Browner has managed to convey during her media blitz is that the oil spill is over. The well has been plugged and the oil has vanished, at least three-quarters, and nature can easily take care of the rest. Not so fast. Here is what happens to oil that is released in the ocean. In 2000, an experiment was conducted off the coast of Norway through a controlled release of oil. Even in such a carefully controlled experiment, the estimate of the oil reaching the surface could not be gauged more accurately than between less than 1% and 28%. The remainder of the oil, by far the greater part, dispersed in microfine droplets of neutral buoyancy. That means if does not have to rise to the surface; it settles anywhere, depending on currents. Since oil dispersants have been used in the Gulf, the percentage suspended — that is not reaching the surface … yet — can be expected to be much higher. So how can anyone categorically claim that three-quarters of the Gulf spill has disappeared?
Numerous plumes of oil up to three miles wide have been observed and also a couple of massive ones ranging 20 and 22 miles. The worst impact so far appears to be a quarter of a mile below the surface. It is these oil tainted strata that have disastrous long-term ecological effects on the base of the food chain. That is plankton, larvae, tiny fish and plants that float with the currents are unable to avoid the plumes and perish, with resulting dead zones in fisheries. Of course, the oil entering the Louisiana marshlands has killed hatcheries and already destroyed the livelihood of shrimp farmers and fishermen.
Gabriel Elizondo reports movingly of the consequences of the Guanabara Bay spill — a mere 8000 barrels in comparison with the Gulf’s four to five million — the fish have not recovered after ten years and some varieties are now extinct. Catches are five to ten percent of what they once were and prices half of market value as the fish are considered tainted. Bubbles of oil became trapped in the sediment on the floor of the Bay. Escaping much later, these began reappearing on the surface causing further recurrent problems in the Bay and on the shore. The mangrove swamps still look like the aftermath of a volcanic eruption.
So where is the oil? Yes, some has been captured and some skimmed off, but past experience indicates that still vast quantities remain below the surface. How soon natural bacteria can decompose it remains conjecture.
Much like the chimera of victory in Iraq (being handed to Iran on a plate), or success in Afghanistan (blown to bits by Wikileaks), or the legerdemain of the Wall Street-centered economic resuscitation (an inflating dollar awaiting the pinprick of reality), we have the specter of the vanishing spill — the bills all coming due eventually to be paid by the next generation.