A Cleaner Future for the Shipping Industry

William Baker

Associate Editor

Loyola University Chicago School of Law, JD 2022

Shipping is the backbone of today’s globalized world and accounts for the carriage of roughly 90% of international trade. Given the sheer number of countries that engage in international shipping, the United Nations created an agency known as the International Maritime Organization (IMO) for regulatory oversight purposes. The IMO subsequently created the International Convention for the Prevention of Pollution from Ships (MARPOL), the most significant international agreement dealing with maritime vessel pollution to date. A predominant responsibility of the IMO is to reduce shipping emissions, seeing as the industry accounts for nearly 3% of global CO2 emissions. Likewise, sulfur emissions are unacceptably high, which has compelled the IMO to take unprecedented steps toward reducing the sulfur content in the grade of fuel oil used by maritime vessels.


The IMO strives to continuously improve safety and security in international shipping through the enactment of environmental protection measures that limit marine pollution. The agency currently has 174 member states and oversees various aspects of maritime shipping regulations, including legal affairs. However, while the IMO develops policy, it cannot enforce it. Rather, a State may adopt an IMO convention into its national law and enforce it accordingly. And while audits are mandatory in order to provide member states with an objective assessment of areas that warrant improvement, the UN lacks the authority to impose punitive measures on noncompliant countries. In short, the agency is limited to providing recommendations and feedback. The onus is on national governments to ensure that vessels located in a State’s territorial waters adhere to IMO anti-pollution measures.

Sulfur: the harmful culprit

Shipping is responsible for 9% of the world’s sulfur oxide emissions. This is attributable to the low-grade bunker fuel used by cargo ships, which contains roughly 2,000 times the sulfur content of diesel fuel used in cars. Sulfur pollution contributes to severe health complications such as lung cancer, heart disease, asthma, and emphysema. It can also lead to acid rainfall, which accelerates oceanic acidification, degrades forests, and devastates crop yields. The IMO enacted Sulphur 2020, which went into effect on January 1st, 2020. This policy has imposed limits on allowable sulfur levels in bunker fuel, leading to a sharp reduction from 3.5% to 0.5% m/m, as adopted by MARPOL. Ships must comply by either using fuel oil with a sulfur content below 0.5% or using an exhaust cleaning device known as a scrubber. Assuming industry players comply with the recently implemented policy, sulfur emissions from ships will decrease by 77%.

Enforcement for the environment’s sake

Singapore’s Maritime and Port Authority recently found a high degree of compliance with IMO Sulfur 2020 rules. It found that 96% of all vessels inspected were using compliant, low-sulfur fuel. A majority of the noncompliant vessels were slightly over the 0.5% threshold, suggesting that their fuel tanks merely contained sulfur residues, as opposed to the tankers being filled with high-sulfur fuel. Singapore credits its record of maintaining an adequate supply of compliant fuel and offering of technical guidance to shippers for yielding high levels of compliance. Very low sulfur fuel oil is currently in abundance, but this could also be attributable to reasons related to COVID-19. Refineries reduced jet fuel production when passenger air travel plummeted after nations closed borders and issued shelter-in-place orders, allowing them to increase capabilities for refining high-sulfur fuel into better quality petroleum products.

While Singapore has provided promising data on Sulfur 2020 effectiveness, compliance with the new guidelines ultimately depends on a national government’s ability to monitor and enforce the adoption of low-sulfur fuel. The United States, for example, requires that all vessels within 100 nautical miles of U.S. shorelines satisfy the sulfur content limit of 0.5% m/m. The U.S. Coast Guard or the Environmental Protection Agency (EPA) may bring an enforcement action against noncompliant ships. Nevertheless, industry analysts estimate that compliance will hover around 80% over the next year and likely won’t reach 100% for at least the next four year. Not all international ports have the wherewithal to perform intensive marine fuel quality tests, and not all countries have ratified this into their national rule of law. Despite these shortcomings, the IMO’s Sulfur 2020 initiative is paving the way toward cleaner oceanic waterways and a more environmentally conscious maritime shipping industry.