In order to control the air pollution caused by ships and improve ambient air quality, China set up three domestic emission control areas (DECAs) in 2015 in the Pearl River Delta, the Yangtze River Delta and Bohai Rim (Beijing-Tianjin-Hebei) waters. In order to meet the emission requirements established at the 70th meeting of the Marine Environmental Protection Committee (MEPC), China intends to apply for the establishment of three international Emission Control Area (ECA) in 2030 for these DECAs. This paper discusses existing technologies to reduce emissions of nitrogen oxides (NO_x) and sulphur oxides (SO_x), and examines the abatement costs for the shipping industry in the year 2030 to comply with this action. Based on an examination of the literature and data collected for this study, four traditional alternatives, low-sulphur fuel, sulphur scrubbers/exhaust gas cleaning systems (EGCS), selective catalytic reduction (SCR), and exhaust gas recirculation, are analyzed. The analysis finds that switching to low-sulphur fuel is the best technical solution for SO_x emission reduction, and the installation of SCR is the best technology for reducing nitrogen. In addition to traditional emission reduction technologies, the use of shore power facilities and liquefied natural gas (LNG), two alternatives welcomed by China's green shipping industry, are also considered in this paper. The expected average abatement cost of these alternatives in the year 2030 are USD 2.866 billion, 0.324 billion, 1.071 billion, 0.402 billion, 0.232 billion and 0.34 billion, respectively.