China is the world’s second largest economy and the largest trading nation in the world. Its coastline is visited by thousands of cargo-carrying ships on a daily basis. The Greater Pearl River Delta (GPRD), which sits in southern China facing the South China Sea, is a heavily populated and prosperous region with heavy ship traffic. Because this traffic contributes to poor local air quality, the Chinese government has identified the GPRD region as a key target for steps to control emissions from ships.
This working paper compiles a high-resolution ship emissions inventory in this region. The purpose of this work is threefold:
- To quantify the magnitude of major air pollutants from oceangoing vessels (OGVs);
- To identify the top contributing ship classes in this region; and
- To understand the distribution of at-sea emissions from OGVs, from at berth to 200 nm offshore as a first step to identifying control polices.
Our results showed that:
- In 2015, OGVs emitted 104 thousand tonnes (kilotonnes [kt]) of sulfur oxides (SOX), 14 kt of particulate matter (PM), and 150 kt of nitrogen oxides (NOX). This is approximately 24%, 3%, and 17% of respective emissions from all sources in the GPRD region.
- Container ships alone emitted about 60% of all air pollution from OGVs in 2015, making them a clear target of future air pollution control policies. Bulk carriers and oil tankers were also important contributors to total emissions.
- In our study region, about 9% of total emissions were emitted at berth. This share increased to 63% at the 12-nm boundary and then continued to increase mildly moving further away. The 96-nm boundary captured about 82% of total emissions. Expanding the current Domestic Emission Control Area (DECA) regulations to 12 nm would reduce emissions roughly 7 fold. Further expansion, for example via an international emission control area (ECA) out to 100 nm, would provide even greater benefits.