Korea has become one of the world’s largest economies based on robust economic growth dubbed the “Miracle of the Han River.” Lying behind phenomenal economic growth were ports and the shipping industry that provided doors and routes to the whole world. Around the world, countries that have advanced economies have ports that are just as well developed as their capital cities, including Liverpool of the U.K., Baltimore of the U.S. and Yokohama of Japan. In Korea, the case in point would be Busan. However, Korea’s largest port has now lost its once mighty stature of the booming era of the past, and is increasingly transforming into an environmental headache and is being shifted to suburbs of the city. This is because risks and environmental burden stemming from logistics and transportation now outweighs economic gains that ports have to provide.
According to a report released by the Environment Ministry in 2017, ultrafine dust emitted in Seoul amounted to 2,524 tons, while that in Busan came to 2,544 tons. It would not be proper to simply compare the amounts of ultrafine dust emitted based only on population, but in light of our common sense, it is difficult to understand why Busan, whose population is less than 4 million, is producing more ultrafine dust than Seoul with over 10 million residents.
The impact of port as a pollutant can be more clearly revealed through comparison between port cities. As much as 51.4 percent of total fine dust was generated by vessels in Busan, which processed the largest volume of oceangoing freight among the Korean ports in 2017 as 49,842 vessels visited the port. The ratio is far larger than second-ranked Incheon, where 18,118 vessels accounted for 14.1 percent of total fine dust produced in the port city.
Then, why ports have become the main culprit of fine dust emission? The real culprit that has made ports such environmental headache is none other than oceangoing vessels. Unlike automobiles, vessels often use low-grade fuel such as Bunker C oil containing a large volume of surfer. For this reason, if vessels and vehicles combust the same amount of fuel, the volume of surfer emitted by the vessels reaches 3,500 times that by automobiles. A large cruise ship generates an estimated volume of surfer dioxide that is equivalent to the volume emitted by 3.5 million diesel vehicles, according to a study. Surfer dioxide, which is emitted when the internal combustion engine in the automobile or vessel burns fossil fuel, is a major cause of fine dust.
Meteorological characteristics of coastal regions are another cause of pollution in port cities. In coastal regions where ports are sitting, land heats up faster than the ocean during daytime, which causes ascending air currents, which in turn generates sea breezes from the ocean to land. Reversely, land cools down faster than the ocean at night, which causes land breezes from land to the ocean. However, temperature variations are smaller at night than daytime, and thus the strength of land breeze is far weaker than that of sea breezes. The problem is that this gap helps pollutants generated in vessels constantly pile up on shores.
There are positive developments recently. Measures that cater to the characteristics of different ports are being devised to counter the fine dust problem, including supply of electricity from land to vessels to help reduce idling of the vessel engines, and slowdown of cruising speed of oceangoing ships within ports. However, in order to improve air quality in port cities, Korea needs a comprehensive measure that takes into consideration not only sources of pollutants from vessels but also meteorological characteristics of coastal regions. Ulsan recently constructed a meteorological maritime and port solution that comprehensively monitors weather and air at the port to come up with effective countermeasure. Likewise, we hope that measures customized for Busan that comprehensively manage weather and air will be put into place, so that Korea’s No. 1 port city can dump its tarnished reputation as one of the world’s 10 most polluted ports sooner rather than later.