As the global collapse in fossil fuel demand leaves oil tankers—and their toxic cargo—idling offshore around the world, the International Council on Clean Transportation (ICCT) is raising concerns about the risks to air quality and marine life.
“In recent days, as many as 32 tankers were anchored near Los Angeles and Long Beach,” reports Grist. “That is about triple the typical number of tankers in those spaces.”
Off the U.S. west coast alone, about 20 million barrels of unsaleable oil were sloshing about inside anchored tankers as of May 11, “nearly enough to satisfy a fifth of the world’s daily oil consumption,” reports Grist, citing data from research firm Kpler. Simply by sitting idle, these tankers are “still generating the equivalent daily footprint of driving roughly 16,000 passenger cars.”
And that’s not the only harm being wreaked by the stalled oil carriers. Clustered together as they are, the tankers may also “pose an ongoing risk to air quality” for Californians, said ICCT senior researcher Bryan Comer. Data from the organization shows that the largest of the California tankers “burn nearly four tons of petroleum-based fuel every day they’re at anchor,” reports Grist, meaning that each vessel “emits more than 11 tons of CO2 per day—the equivalent of driving nearly 800 passenger vehicles.” Other emissions produced by anchored tankers include particulate matter (almost 4 kilograms per tanker per day) and sulphur dioxide (about seven kilograms each per day). Long connected with heart and lung disease, sulphur emissions have also recently been linked to increased mortality from COVID-19.
Shipping regulators are cracking down on sulphur emissions, but the new regulations may not go far enough. “As of this past January, oceangoing vessels can burn fuel with only 0.5% sulphur content, a significant drop from the previous limit of 3.5%,” writes Grist. California also now requires “ships sailing within 45 kilometres of its coastline to use lighter ‘distillate’ fuels with just 0.1% sulphur content.” Positive moves perhaps, but “even the cleaner-burning distillate fuel has nearly 70 times the sulphur content of on-road diesel fuel,” Grist notes.
Just how much the idling tankers will affect overall shipping emissions remains uncertain, said Comer, since researchers will need to account for things like the 15.5% plunge in cargo volumes at the Port of Los Angeles between January and April. But the scene playing out in California is being repeated across the globe: stranded oil behemoths are likewise “crowding ports in places like India, Singapore, and the U.S. Gulf Coast, serving as temporary storage units or waiting indefinitely for customers.”
Many of these ships are putting the marine environment at risk. “Certain tankers burn dirty bunker fuel—a byproduct of the petroleum refining process—and use ‘open-loop’ scrubbers to reduce the ship’s sulphur output in line with regulations,” writes Grist. Such scrubber systems are no friend to marine life, as they “mix water with exhaust gas, filter it, then dump the resulting washwater—an acidic mixture that contains carcinogens like polycyclic aromatic hydrocarbons and heavy metals.” According to ICCT estimates, “large vessels emit nearly 40 tons of scrubber washwater every hour.”
Fortunately for California’s marine ecosystem, such scrubber use is prohibited in that state, and every tanker is being closely monitored to ensure that collisions (and consequent spills) do not occur—and that the vessels are neither leaking oil, nor dumping waste.
