Effectiveness of current technology in GHG reduction – A literature survey

In 2018 during the 72nd session of the Maritime Environmental Protection Committee (MEPC) IMO adopted its initial strategy for the reduction of greenhouse gas emissions (GHG) from the ships to meet the Paris Agreement Goals, 2015. This is considered as a major milestone in formulizing a clear strategy by IMO towards its objective of reducing the global GHG emissions from the ships. The strategy had two primary objectives: the first was to decrease total annual GHG emissions by at least 50% by 2050 compared to 2008 levels. The second objective was to promote the phasing out of GHG emissions entirely. In 2020, the International Maritime Organization (IMO) conducted a study which revealed that greenhouse gas (GHG) emissions from shipping had increased by 9.6%. The rise in global maritime trade was identified as the main factor behind this increase. IMO's 2020 study also concluded that reducing GHG emissions by focusing only on energy-saving technologies and ship speed reduction would not be enough to meet the IMO's 2050 GHG reduction target. Therefore, greater attention needs to be given to the use of low-carbon alternative fuels. To understand the effectiveness of currently available technologies in reducing GHG emissions from ships, a literature survey was conducted in this study. The survey examined a range of related articles published between 2018 and 2022. This study aimed to identify the current stage and the quantity of literature available on various technologies and, more importantly, serve as a decision-making support tool for selecting a technology under specific circumstances in a quantitative manner. The technologies were divided into four groups: those that utilize fossil fuels, those that use renewable energy, those that use fuel cells, and those that use low-carbon or alternative fuels. The literature survey was conducted using Web of Science (WoS) and Google Scholar. The results of this study will also help to identify clear research gaps in comparing the effectiveness of various available technologies to reduce GHG emissions. Ultimately, the aim is to develop a comprehensive strategy that can be used to reduce GHG emissions from shipping and contribute to the global fight against climate change.