“One Giant Container Ship Can Emit Almost the Same Amount of Cancer and Asthma-Causing Chemicals as 50 Million Cars, Study Finds.”
My investigation took the drastic form of reading the article. The outrageous claims kept on coming: “Confidential data from maritime industry insiders based on engine size and the quality of fuel typically used by ships and cars shows that just 15 of the world’s biggest ships may now emit as much pollution as all the world’s 760m cars.”
Really? According to these statistics, we could all keep driving our SUVs if we simply dry dock a few of the world’s 90,000 container ships. Environmental crisis averted.
But here’s where truthiness collides with the truth: The article states that all shipping accounts for only 18 to 30 percent of the global nitrous oxide emissions and 9 percent of all sulfur oxide emissions. These 90,000 container ships equal many thousand times more than all the cars on the world’s roads, yet account for a minimal amount of the world’s worst greenhouse gases. That must mean that cars account for even way fewer greenhouse gas emissions. My head spun with cognitive dissonance.
The truth is that the transportation sector accounts for just 14 percent of all greenhouse gases. Most nitrous oxide comes from agriculture. Must sulfur oxide comes from industry and power plants.
The Dirt on Bunker Oil
Truthiness aside, container ships do present a real problem. Their dirty secret is bunker oil. This is the most common type of fuel used on ocean-going vessels. The most common form of bunker oil is Bunker C oil, also known as residual fuel oil or heavy fuel oil. This is a highly viscous, low-quality, and dense oil that must be heated in order for it to become liquid enough to run through an engine. It’s so thick that it’s just one step away from being asphalt. It is distilled from crude oil, and it is the most polluting form of oil because of the contaminants that cannot be removed. It literally settles on the bottom of the barrel during the refining process.
So why do shipping companies use it? Because it’s really cheap. And container ships use a whole lot of it. Good statistics are hard to come by, but here are a few: Bunker oil is about $600 per metric ton, and a metric ton is about 358 gallons. That comes out to and an average of $1.67/gallon. The average container ship uses 108 metric tons per day. That’s $64,800 per day in fuel costs.
In a perfect world, bunker oil has no business being burned and spewed into the air, regardless of the cost. It has a sulfur content of 27,000 parts per million. Diesel fuel has a sulfur content of 15 parts per million. Less is better. Sulfur isn’t a greenhouse gas, but it is a major component of acid rain and it has lots of negative affects on plant and animal life. (Sulfur hexafluoride, on the other hand, is the worst greenhouse gas ever detected. It’s warming potential is 23,900 times that of carbon dioxide and it has an atmospheric lifetime of a couple thousand years. But it isn’t released when bunker oil is burned.) The rate of sulfur in the atmosphere is decreasing, thanks to the Clean Air Act, but no thanks to the shipping industry.
The Good News You Didn’t Hear About
The Guardian story about polluting container ships is from 2009. I can’t explain how or why I stumbled upon it only last week. But what it lacks in timeliness it more than makes up for in seriousness and hopefulness. It cheerfully reports that the U.S government is on the verge of establishing a 230-mile “clean air buffer zone” around its entire coast to protect people and the environment from bunker oil. The mandate will require ships at U.S. ports to burn cleaner diesel fuel instead of bunker oil. This is an easy, peasy switch that should only add an extra penny or so to the cost of your made-in-China stuff. The EPA estimates the new rule will prevent the premature deaths of anywhere between 13,000 and 33,000 U.S. and Canadian citizens each year. Yay!
The 200-nautical mile clean air buffer zone is officially called the North American Emission Control Area (ECA), and it went into effect in 2012. This zone drastically reduces sulfur dioxide, nitrogen oxide, and particulates emitted by container ships and was approved by the International Maritime Organization (IMO). The IMO had previously sanctioned ECAs along the Baltic Sea and the North Sea. This momentous, drastic reduction in harmful greenhouse gases should have received a whole lot more attention in the press. (This article, however, notes the negative impact the ECA will have on the cruise industry. As if an extra couple bucks a day is going to prevent people from embarking on their Carnival Cruise. You’d think people would be happy that cruise ship smokestacks are no longer clogging their lungs the way that all-you-can-eat fried shrimp is clogging their veins.)
People need to see that international organizations and the EPA are making great strides in implementing policies to curb climate change and improve public health. Proving that change is possible paves the way for even more positive change. As a sentient species, we shouldn’t object to a slight increase in fuel oil prices if the trade off is better health and a cleaner environment.
The lesson here is that anyone can write a headline of truthiness, but discerning the truth requires digging into the devilish details.