The J-Park Simulator is a research activity with the ultimate goal of showing how various scenarios affect the real world, in particular carbon emissions in Singapore. The reduction of carbon emissions is a complex multi-dimensional problem and one of the greatest challenges is low interoperability between different domains: as data and software from various domains may be significantly different due to different definitions or standards etc. The J-Park Simulator aims to increase this interoperability by utilising latest ideas from semantic web technologies and Industry 4.0 to describe and model real entities from different dimensions e.g. economic, technological, environmental and social, to fulfil objectives such as simulation and optimisation in cross-domain and multi-level scenarios. This research will allow stakeholders to have a holistic approach to solving complex multi-dimensional problems.