Bunker Fuel: The Major Emission Source We Can’t Forget About

Bunker Fuel: The Major Emission Source We Can’t Forget About

Written by Jace Bradshaw
Published 16 December 2018

…just 15 of the world’s biggest ships emit as much pollution as all the world’s cars…

Maritime transport is involved in 90% of the world’s trade, meaning some part of every gift you buy during the holiday season most likely made its way to you on the back of a ship.  The reason for this dominance is simple: it is by far, the most cost-effective way to move huge amounts of goods and raw materials around the world.

The cargo ships used to move the global economy have massive, one-hundred thousand horsepower engines that run 24 hours a day most days of the year. These engines are very efficient for their size. According to the Swedish Network for Transport and the Environment, maritime shipping also produces fewer greenhouse gases for each ton of goods transported one kilometer than air or road transport.

How does this reconcile with the Guardian’s report of several years ago that claimed, “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?” The answer is that modern ships get their efficiency from moving such large amounts of cargo in one trip. But this does not make them clean. It only makes them clean-per-ton. In fact, shipping is responsible for approximately 24% of the world nitrogen oxide pollution and about 9% of the global sulfur oxide pollution. And the reason for these large amounts of noxious gases is what fills up the gas tank: bunker fuel.

Bunker fuel, or heavy fuel oil (HFO), is a cheap byproduct of petroleum distillation. The process uses fractional distillation to separate components of petroleum based on weight. Light fuels include propane, gasoline, and jet fuel. These fuels burn relatively clean because they are made up of shorter chains of carbon and small amounts of nitrogen and sulfur. At the other end, the heaviest fuel is heavy fuel oil. In fact, the only heavier by-product is asphalt. This fuel burns very dirty because it is made up of long carbon chains and has larger amounts of nitrogen and sulfur. HFO’s composition makes incomplete combustion more likely which leads to the noxious gas release that devastates our environment by decreasing tree foliage and leading to ‘acid rain.’

These emissions do more than hurt the environment; they also kill people.  James Corbett, a professor of marine policy at the University of Delaware, concluded in his landmark study Mortality from ship emissions: a global assessment, “Our results indicate that shipping-related emissions are responsible for approximately 60,000 cardiopulmonary and lung cancer deaths annually, with most deaths occurring near coastlines.” He goes on to say, “Ship pollution affects the health of communities in coastal and inland regions around the world, yet pollution from ships remains one of the least regulated parts of our global transportation system.”

That lack of regulation seems to be changing. Governing bodies around the world are establishing Emission Control Areas (ECA) that are designated buffers around ports and coastal communities to limit pollution. The broadest regulations placed so far come from the International Maritime Organization (IMO), and limit the maximum amount of sulfur present in fuels burned near the shore. These restrictions were shown to reduce the percentage of sulfur and other particulates from 4.5% to 0.1% inside an established ECA in 2015.

As of 2013, sulfur and particulates levels of up to 3.5% continued to be permitted outside an ECA, but the International Maritime Organization has planned to lower the sulfur content requirement outside the ECAs to 0.5% by 2020. However, this date can be pushed back to 2025.

With these regulations, demand is expected to shift to marine gasoil. Marine gasoil has lower sulfur and generally burns cleaner. Less gasoil is normally produced, so increasing demand will naturally drive up prices. Thomson Reuters Research estimates fuel makes up about half a ship’s daily operating cost. Based on an average fuel consumption, a ship using cleaner fuel faces extra daily expenses of about $6,000 to $20,000.

So as consumers but also residents of this planet, it is important to consider the balance between saving money and breathing cleaner air–having less asthma and pneumonia. Take this trade-off into consideration this holiday season. And consider reaching out to the IMO to express your feelings about the progress they are making.