Recent studies have brought forward the critical role of emergent properties in shaping microbial communities and the ecosystems they are part of. Emergent properties - patterns or functions that cannot be deduced linearly from the properties of the constituent parts - underlie important ecological characteristics such as resilience, niche expansion, and spatial self-organisation. While it is clear that emergent properties are a consequence of interactions within the community, their non-linear nature makes mathematical modelling imperative for establishing the quantitative link between community structure and function. As the need for conservation and rational modulation of microbial ecosystems is increasingly apparent, so is the consideration of the benefits and limitations of the approaches to model emergent properties. Here we review ecosystem modelling approaches from the viewpoint of emergent properties. We consider the scope, advantages, and limitations of Lotka-Volterra, consumer-resource, trait-based, individual-based, and genome-scale metabolic models. Future efforts in this research area would benefit from capitalising on the complementarity between these approaches towards enabling rational modulation of complex microbial ecosystems.