4.1.1. Intergovernmental Panel on Climate Change (IPCC) Emission Coefficient

Emissions from ships include greenhouse gases (GHGs) emitted from the diesel engines, steam engines with boilers, and gas turbines, which are the main engine types used to power ships, ranging from leisure crafts to large-scale freighters. The emitting crafts, which are the focus of the ship section of the "Intergovernmental Panel on Climate Change (IPCC) Guidelines 2006" report, include sailing ships, fishing boats, and other ships. The method for calculating GHG emissions is presented in Table 4 [30].


**Table 4.** Calculation methods according to emission gas.

The activity data used in the Tier 1 method are based on fuel consumption, thus emission coefficients are needed for each fuel and pollutant. In the case of CO2, SO2, and heavy metals, there is a close relationship between the emission coefficient and the CO2, SO2, and heavy metal content of the fuels. The calculations must take into account the related pollutant content in the fuel for each year and the target class of the ship according to the national region.

Tier 1 and Tier 2 emissions were calculated by using a method that uses petroleum sales as the index for the basic level of activity. It performs calculations by assuming the averaged characteristics of each ship type. The method to calculate Tier 3 emissions was based on the operating profile information of the ship. The Tier 3 method can be used when it is possible to collect not only the data on the engine, fuel usage, and duty cycle of the ship, but also information about its voyage. Because the actual voyage data of the ship must be taken into account, port arrival/departure statistical data regarding the voyage of the ship was used to calculate the fuel consumption and emissions while taking into account the

emissions for each operating profile and the ship type, fuel type, engine type, technical specifications, and engine load, yearly operating time, etc.
