Discussion on the proposed area of an international ship emission control area in China

Abstract

If China intends to designate an international ship air pollutant emission control area (ECA) adopted by the International Maritime Organization (IMO), how to establish the proposed area is a key issue. The paper first analyzes the geographic scope of the four IMO’s ECA. Comparatively analyzes the actual situation of China’s coastal areas, and then set up four scenarios, namely (1)12 nautical miles (nm) from the territorial sea baseline, which is the boundary of China’s territorial sea;(2)24 nm from the territorial sea baseline, which is the boundary for China’s contiguous zone;(3)50 nm from the territorial sea baseline; and (4)100 nm from the territorial sea baseline. Using the bottom-up method based on Automatic Identification System (AIS) data of the year 2014 to calculate the proportion of ship emissions in the four scenarios, the results show that the proportion of ship emissions within 12 nm, 24 nm, 50 nm and 100 nm from the territorial sea baseline are 67%, 75%, 82% and 88% respectively. It is recommended that the proposed area of an IMO-adopted ECA in China is 100 nm from the territorial sea baseline, which can control the impact of nearly 90% of the ship emissions, and can avoid the ship from rerouting as much as possible. However, in actual operation, the disputed waters should be avoided. This work may provide reference for further research.