Climate change and global warming are primarily driven by anthropogenic greenhouse gas (GHG) emissions from human activities. In the early days, there were debates that climate change was a conspiracy, or exaggerated. Over time, evidence supporting human-induced climate change has become overwhelming, leading to a broad scientific consensus on anthropogenic global warming. The Kyoto Protocol (1997) marked the first global effort to mitigate GHG emissions but proved limited in its effectiveness, primarily due to the absence of binding commitments from major emitters and the rapid industrial growth in developing countries. The Paris Agreement (2015) introduced a more flexible, bottom-up framework, requiring all parties to set Nationally Determined Contributions (NDCs) to reduce emissions in alignment with global temperature targets. Despite progress in international climate policy, global energy consumption remains heavily dependent on fossil fuels. Furthermore, the GHG emissions from international shipping are the eighth largest source of GHG emissions but were not included in the national GHG reduction targets. This was the starting point for the IMO to develop GHG reduction strategies for ships.