This study investigates the environmental impacts of two urban freight-distribution strategies: in-store pickup with returns and last-mile delivery by professional logistics service providers. With the rapid growth of e-commerce, understanding the carbon footprint of alternative delivery and return channels is critical for sustainable urban logistics. A Monte Carlo simulation-based approach is employed to evaluate CO 2 emissions generated by these two strategies under stochastic operational conditions. The simulation model incorporates real-world logistics data, including transportation distances, vehicle types, fuel-consumption rates, and the number of packages handled per trip. A total of 10,000 individuals and delivery operations were modeled under probabilistic scenarios to estimate emissions under varying conditions. The results indicate that in-store pickup and return activities conducted by individual consumers generate higher CO 2 emissions than optimized last-mile delivery services when the number of collected packages is low. The break-even analysis reveals that in-store pickup becomes environmentally preferable only when at least 24 packages are collected per trip under baseline conditions. When return-related emissions are allocated to courier-based delivery, this threshold shifts downward to approximately 17–20 packages, depending on the assumed return rate. Therefore, in-store pickup can be considered an environmentally sustainable option only under specific conditions, such as high levels of package consolidation or the use of low-emission transport modes. The findings provide important implications for consumer behavior, logistics system design, and urban freight policy-making. The results highlight the need for strategies that promote electric delivery fleets, shared mobility solutions, and behavioral awareness to reduce urban transport emissions.
İlknur Yardımcı Coşkun (Tue,) studied this question.