Dropping money at bricks-and-mortar shops can have a bigger carbon footprint than some forms of e-commerce.

To cut the carbon footprint of your online purchases, have them delivered by local stores.

As low-cost, fast-shipping e-commerce sites proliferate, consumers have embraced the convenience of online shopping. Sadegh Shahmohammadi at Radboud University in Nijmegen, the Netherlands, and his colleagues compared greenhouse-gas emissions associated with three types of retail shopping in the United Kingdom: purchases made at bricks-and-mortar stores; online purchases that are delivered by local stores; and ‘pure-play’ e-commerce, or online purchases delivered from a central warehouse.

The team summed the greenhouse-gas emissions associated with storage, packaging and transport of basic consumer products, and estimated that pure-play shopping had 2–5 times the climate impact of local-store delivery. Bricks-and-mortar shopping had slightly higher carbon emissions than parcel delivery from local shops.

Most of the greenhouse-gas footprint for each type was due to ‘last-mile’ emissions — the carbon cost of delivery from a shipping depot to the final destination. Changes to last-mile delivery methods, such as a switch from vans to cargo bicycles, could help to reduce online shopping’s greenhouse-gas impact, the researchers say.