This paper provides and comments upon the results of an in-house study of the greenhouse gas emissions generated over the life cycle of diesel-fuelled (DF) and electric buses (BEV) used by a chosen municipal transport company (MTC) operating in the urban area officially referred to as the Metropolis of Upper Silesia and Dąbrowa Basin (GZM). Based on real-life data obtained from the municipal transport company in question, comparative analyses of the relevant greenhouse gas (GHG) emission rates, established in line with the cost-benefit analysis (CBA) and life cycle assessment (LCA) methodologies, were conducted. The CBA methodology currently in use does not take several key environmental aspects into account in the calculations performed for purposes of carbon-neutral public bus transport, which is why the solution proposed in this paper entails using the LCA method to calculate GHG emissions with the aim to expand and add detail to the methodology employed when calculating climate change costs under cost-benefit analyses performed with an outlook extending to the year 2027.