Manufacturing companies have a strong impact on climate change due to their immense degree of greenhouse gas emissions. Hence, it is mandatory that these companies take measures to reduce their greenhouse gas emissions. A promising measure is the reduction of the carbon footprint caused by single processes within manufacturing process networks. Various approaches to reduce the carbon footprint of single manufacturing processes have already been described in literature. However, there is a scientific need for action when it comes to the systematic reduction of the carbon footprint of queueing systems which are typically an integral element of manufacturing process networks. Therefore, this paper presents a novel approach that aims to assess and reduce the carbon footprint of manufacturing queueing systems systematically. First, a general queueing system is defined and its variables that contribute to the carbon footprint in manufacturing are determined. Subsequently, a mathematical model is designed which enables an abstract description of the interactions of different input variables on the carbon footprint of queueing systems in manufacturing. Afterwards, recommendations to reduce the carbon footprint of queueing systems are developed based on the previous findings. Finally, the approach is validated for a specific manufacturing queueing system with a discrete-event simulation study. The results give foundations for further research on dependencies within manufacturing process networks.