In this paper, we have identified and addressed some environmental considerations in the context of intermodal freight transportation and proposed ways to introduce environmental costs (greenhouse gas emissions, to be specific) into planning models for transportation. We have proposed a formulation for scheduled service network design problem with fleet management, which, to our knowledge, is a first to explicitly consider greenhouse gas emissions as a primary objective. The formulation has been implemented on a real-life intermodal rail network data. Computational experiments have been carried out to compare the solutions under time and emission minimizing scenarios. Our results capture and present the trade-offs between conflicting objectives of minimizing time-related and environmental costs, and also provide empirical figures of minimizing time-related and environmental costs, and also provide empirical figures on the order of magnitude that the two objectives might differ from one to the other.