Consumer Carbon Footprint of Fashion E-Commerce: A Comparative Analysis Between Omnichannel and Pure-Player Models in Spain

The rapid expansion of fashion e-commerce has raised concerns over the environmental cost of last-mile deliveries, especially in pure-player models. This preliminary study examines the estimated carbon footprint of TENDAM’s omnichannel model—based on in-store pickup and returns—compared to pure-player home delivery, using a customer-level approach across 11 Spanish cities of varying sizes. A total of 3106 face-to-face surveys were conducted in TENDAM stores, capturing data on mobility behavior, transport modes, trip chaining, and service types. Emission factors were applied using a Python-based analytical model, and results were contrasted with Monte Carlo simulations from existing literature on pure players. Our findings indicate that the average per-service footprint of the omnichannel model is around 400 g CO2−eq, significantly lower than the 1500–3000 g CO2−eq range for pure players. Emissions were especially low in large cities and in street-level stores, largely due to the high rate of walking and multipurpose trips among customers. The study also includes geospatial analysis through interactive influence maps. These results suggest that dense store networks embedded in walkable urban areas can substantially reduce last-mile GHG emissions. While preliminary, the study highlights the potential for omnichannel retail to support urban decarbonization goals and sustainability when integrated with sustainable mobility patterns.