"By then [August] the Deepwater spill will likely have leaked over 200,000 tons of oil into the Gulf of Mexico. By comparison, the Exxon Valdez tanker spilled 37,000 tons into Alaska’s Prince William Sound; the 1969 Santa Barbara spill (which was stopped in about 10 days) amounted to only 12,000 tons.
But the extraordinary nature of this platform spill—the first in this country in 40 years (last year’s Montara spill in the Timor Sea was the first major platform spill anywhere in the world in more than 20 years)—is no excuse to take leave of reason, or avert our gaze from thinking seriously about risk tradeoffs. Right now the United States gets more than 1.6 million barrels of oil a day from the Gulf of Mexico, and if we curtail Gulf exploration and production, we shall have to make up the difference with more imported oil.
"Despite post-Exxon Valdez safety measures, tanker oil spills occur more frequently and release more oil than offshore drilling accidents, by a wide margin. Over the last 50 years, offshore drilling spills, including the Deepwater Horizon, have unleashed a little more than 1 million tons of oil; tanker accidents have spilled 4 million. For every offshore drilling spill, there have been seven tanker spills, many much larger than the Exxon Valdez, only the 40th largest tanker spill on record.
“Even if the Deepwater Horizon spill lasts into the fall, it will still not even be the largest offshore spill in the Gulf of Mexico. That dubious achievement belongs to the Ixtoc 1, a Mexican platform near Yucatán that blew out in 1979 in circumstances similar to the Deepwater Horizon (the blowout preventer failed after a gas surge from the well). It took Mexico’s famously inept Pemex almost 10 months to stop the leak, by which time 460,000 tons of oil had leaked—still the largest accidental spill in world history (Saddam Hussein deliberately fouled the Persian Gulf at the end of the first Gulf War with 1.2 million tons).”
And for the benefit of people fearful of what effects a hurricane might have, well, we already have experience with a hurricane and a much larger oil spill in the Gulf of Mexico.
“The ecological effects of the Ixtoc 1 disaster should be borne in mind when we hear claims that the Deepwater spill will inflict large and long-lasting effects. According to a 1981 study by the Royal Swedish Academy of Sciences, about half of the Ixtoc 1 oil evaporated, and another 25 percent sank to the bottom of the ocean, much of it broken up by wave action and chemical dispersants. The Swedish Academy study estimated that oil from the Ixtoc 1 poisoned a 5,800 square mile area, devastating crab, shrimp, and fish stocks, and leading to large oxygen-killing plankton blooms. Overall fish landings fell by up to 70 percent in Mexican and Texan coastal waters. On the other hand, the 5,800 square mile area represented about 2.5 percent of Mexican Gulf Coast waters. Finally and most ironically, Hurricane Frederick struck the Texas coast in September 1979, and washed away 95 percent of the oil that had reached shoreline beaches and marshes. The current fears of the effects of tropical storms and hurricanes in the midst of the Deepwater spill might be misplaced.”