**Abstract**

In this study, well-to-hull was obtained by life cycle assessment (LCA) and GREET, which is developed by Argonne National Laboratory to evaluate the environmental impact of marine LNG and marine fuel. This study compared the environmental impact of marine LNG and marine fuels, which were caused by green house gases (GHGs) emissions and energy consumption. The effect resulted from well-to-pump (WTP) process and pump to hull (PTH). Natural gas has the potential to generate more greenhouse gases than liquid fuels due to the amounts of leaks of the gas that were sent out of the air during production and processing. Nevertheless, the results showed that the greenhouse gases produced during transportation were enough to reduce the disadvantages (pump-to-hull process). The research expects that the results will be under the environmental policy of South Korea.

**Keywords:** liquified natural gas (LNG), GREET 2018, well to hull, life cycle assessment (LCA), marine fuel, greenhouse gas
