Natural gas produces less carbon dioxide, nitrogen oxides and sulfur oxides per unit heat released than other fossil fuels such as oil and coal. In line with efforts to preserve global environment and to promote sustainable development of world economy, the demand for natural gas has steadily increased. This study was conducted to analyze the risk of GHG (greenhouse gas) release caused by accidents involving natural gas carriers. LNG, which stands for Liquefied Natural Gas, is composed mainly of CH4, so the composition of LNG was assumed to be 100% CH4. Also, the other components of natural gas are not recognized as GHG. To estimate the maximum environmental impact, “Q-Max” which is currently the largest LNG carrier was used as the reference ship. For comparison, CO2 emissions from the propulsion engine were calculated. The environmental impact due to accidents was insignificant compared with the impact of CO2 emissions from the propulsion engine.
