The International Maritime Organization (IMO) is the UN agency responsible for regulating the maritime industries which includes shipping emissions, a complex problem that affects human health and is tied closely with climate issues. Much of the previous research on the IMO is focused on the influence of industry or economic aspects of shipping. This research seeks to expand the viewpoint through the lens of governance which fits well with a multi-actor, multi-layered policy process. It seeks out factors that influence the policy process on the issue area of emissions in the Marine Environmental Protection Committee (MEPC). The article uses qualitative data obtained through ethnographic observation and elite interviews. The data shows that factors external to the IMO, such as geopolitical context, national issues, and climate governance spillover, influence the policymaking in the MEPC. Within the IMO factors influence the process on the organization level, such as norms, principles and negotiations, and on the individual level. The most prominent spillover effects come from global climate governance with the MEPC becoming more political and less technical, which suggests politicization of the Greenhouse Gas issue has affected the organization, its norms, and its policymaking process. Consequentially, this affects factors in the policymaking process on other levels, through principles, negotiations, processes, and human factors, such as personal capacity and relationships. It also finds individuals may influence the process from the bottom up. The findings offer insights for future policy processes in the MEPC and other international organizations that deal with emissions issues.