Delineating a Chinese emission control area: the potential impact of ship rerouting on emissions

When making travel plans, a traveler’s first choice is usually the quickest available
trip from origin to destination. If the shortest route contains a toll, the traveler might
consider a slight detour to avoid the additional charge. Ship operators make similar
decisions while at sea. Because regional environmental regulations designed to
reduce emissions from ships can increase operating costs, ship operators may choose
a different route, avoiding the additional costs but also reducing the efficacy of the
regulations themselves.
As China tackles its air quality issues, government regulators have turned their focus
to shipping, an industry that burns thousands of tons of highly polluting heavy fuel oil
(HFO) near densely populated coastlines every day. Historically, one way to reduce air
pollution from ships is by establishing an Emission Control Area (ECA), a geographic
region designated by the International Maritime Organization (IMO) where more
stringent emission standards apply. China has already implemented domestic emission
control areas in three port clusters along China’s coastline, although they are smaller
and currently have less stringent standards than an IMO ECA.