THE LAST MILE
Getting items to customers’ doors from a fulfilment centre — referred to as the “last mile” or “last kilometre” of shipping — is one of the hardest stages to make less polluting, Sreedevi said.
Emissions rise even more when customers place multiple small orders throughout the week.
“If I place an order this morning and then I place an order this evening and choose fast shipping, the company might have already processed my morning order and wouldn’t wait for my evening order to consolidate,” she said.
And sending more half-full trucks out on the road means more trips overall.
“Imagine you’re not only sending a half-full truck, you’re also bringing back that truck empty. … Emissions are going to go up,” Sreedevi said.
REDUCING EMISSIONS
Consumers can lower emissions if they’re willing to wait even a tiny bit, and they’ll save money at the same time, said Christopher Faires, assistant professor of logistics and supply chain management at Georgia Southern University.
Delaying delivery by one to two days can result in a 36 per cent reduction in carbon dioxide emissions, and three to four days pushes that reduction to 56 per cent, so opting for standard or delayed shipping instead of next-day or two-day shipping helps, according to Sreedevi.
Amazon’s Atkins said changes to their network are cutting emissions linked to fast delivery. The company has expanded the use of electric delivery vans and shifted more packages to rail and to delivering by foot or bicycle in dense cities.
“Aviation is very carbon-intensive relative to ground shipping,” said Atkins. “One of the other things that Amazon and other logistics companies are looking at doing is: How do we mode-shift to less carbon-intensive forms of transportation?”
Amazon says providing shipping options that encourage customers to consolidate orders has also helped. Data for the first nine months of 2025 shows that when customers chose a single delivery day for all items, it reduced more than 300 million delivery stops and avoided 100,000 tons (90,718 metric tons) of carbon emissions, according to Atkins.
People are more likely to delay or consolidate orders once they understand the environmental impact of fast shipping, according to Sreedevi, who co-authored a 2024 study of delivery customers in Mexico.
“A significant number of consumers decided to wait for longer delivery or delayed their shipping when we showed them the environmental impact information in the form of trees,” said Sreedevi. “So it’s important that they are educated.”
While fast shipping isn’t likely to go away, experts say its climate impacts can be meaningfully reduced through small behaviour shifts, both from shoppers and companies. Bundling orders, skipping the overnight option and choosing a single weekly delivery can all make a difference.