In the context of lot-sizing and scheduling, minimizing energy consumption is a typical criterion to improve a company’s ecological footprint. In the literature, trade-offs between energy consumption and some economic criterion (e.g., energy costs) are analyzed. However, indirect carbon dioxide emissions are also an important aspect for the ecological footprint of a company. One might deduce that minimizing energy consumption also minimizes the indirect emissions of a company. In this talk, we show that such a positive one-to-one relationship needs to be questioned under time varying energy prices. Here, based on an instance of a tri-criteria simultaneous lot-sizing and scheduling problem, we determine the three-dimensional Pareto front via the elastic constraint method to demonstrate that all three criteria - time-dependent energy costs, energy consumption and corresponding carbon dioxide emissions - are conflicting. Due to the potential conflict between the three objectives, we refer to the tri-criteria optimization problem as eco-energy-efficient simultaneous lot-sizing and scheduling.