Private transportation is the most environmentally inefficient method as it generates the most amount of carbon emission per item purchased. However, the use of delivery vans produces less carbon emission to the environment due to efficiency of trip chaining – lots of goods can be delivered en-route (as highlighted in the figure above).

Nonetheless, online purchase opens the possibility of failed delivery, where consumers are not home for collection of goods. Hence, this results in re-deliveries and when the rates of failed delivery become very high, futile deliveries may cause unnecessary carbon emissions.

Also, with the aim of profit maximisation and increasing consumer base and satisfaction, many online companies have adopted free return policy for customers. This policy comes at an environmental cost. As consumers now have the choice of returning goods that do not fit or suit them, they are less prudent in their purchase. Many are seen buying various sizes and colours of the same good, and then returning some or all. Again, unnecessary carbon emissions are emitted when special delivery trucks recollect these parcels from consumers. The free return policy has implicitly encouraged us to purchase more than needed as we do not have to consider any consequences.

E-commerce businesses have also tried to increase their market share by promising fast or same day deliveries. This enticing factor resulted in delivery trucks being less efficient as the volume of goods contained in the trucks may not be maximized, and delivery routes are not optimised when they go out of the way to deliver. Also, the use of air freight to speed up delivery process generates huge amount of carbon emission.

All these factors may in turn backfire the potential environmental advantages of online shopping.