If current trends continue, the annual global volume of deliveries could even double from more than 315 billion parcels in 2022 to as much as 800 billion per year in 2030, the study notes.
Even without taking these growth projections into account, the authors estimate that, if there is no change in the fleet composition of multinational e-commerce companies, global deliveries will emit up to 160 megatonnes of CO2 each year by 2030, equivalent to the emissions of 44 coal-fired power plants.
"This means that more than a billion trees would have to be planted each year and left to grow for ten years to save the carbon pollution from last-mile deliveries," the researchers argue, referring to the last leg of a delivery, from the distribution depot to the delivery point, which does not necessarily have to be one mile.
Human health implications
"Last-mile emissions from e-commerce companies are expected to result in up to 168,000 cases of increased asthma, up to 285,000 cases of increased respiratory symptoms and up to 9,500 premature deaths," they argue in their analysis entitled "The Price of Convenience: Revealing the hidden climate and health impacts of the global parcel industry".
According to Amazon's 2021 Sustainability Report, less than 7% of all Amazon deliveries in Europe are made in electric vehicles or other modes of clean mobility, while in the US this figure drops to 1%, they add, emphasising that while Amazon has committed to deploying 100,000 electric delivery vans, there are currently only around 3,000 on the road.
They warn that the transport associated with these orders could exacerbate the climate crisis, as this sector is "the world's largest source of new GHG emissions", responsible for 12% of global emissions, and 29% of Spanish emissions.
Despite the environmental costs, according to a survey published at the end of April by the e-commerce logistics platform Packlink, 76% of consumers believe that returns for their online purchases should always be free, a percentage that is 3% higher than last year's assessment.
By generations, Packlink found that younger people - generally "more aware" of the climate footprint of transport, they say - are the most receptive to paying for returns, while baby boomers are the most reluctant.
Their report claims that the return rate for online purchases can be as high as 3%, compared to less than 10% in physical shops.