Shipping accounts for 15% and 13% of global NOx and SOx emissions respectively and is a major source of air pollution in China’s large port cities, such as Shenzhen, Hong Kong and Shanghai. Beginning in 2016, China started implementing, in stages, a low sulfur marine fuel standard in key port regions. To support the government on further tightening the sulfur fuel limits and imposing NOx control on ships, NRDC joined three NGOs, Tsinghua University, Fudan University, and three Chinese government research institutes in conducting a series of studies that evaluated the costs, benefits, and feasibility of establishing an international Emission Control Area (ECA) in China. Research findings are being summarized in a recommendation report for the Ministry of Transport in December. NRDC advised on the report’s conclusions and contributed a section on ECA enforcement experiences in the European Union and North America to underscore the feasibility of effective enforcement of an ECA in China.