Most existing retailers did not own or run a private logistics network, they would use XPO, R+L, Old Dominion, etc.
In order to get that amazing fast delivery time, Amazon had to create their own system. The creation of that system, created a large amount of Carbon emissions at it's onset just with the requisite vehicles require to make it happen. It also set off an arms race between logistics enterprises to try and deliver the same performance, leading to further emissions.
>The primary function of Amazon Air is to transport Amazon packages from distant fulfillment centers that are outside of Amazon's local ground linehaul network for a specific area.
They have their own air cargo service for shipping packages between Distribution centers. They wouldn't invest in that unless they had enough volume to make it profitable.
I get that it is easy and convenient but please don't try to claim that it is ecological.
https://en.wikipedia.org/wiki/Amazon_Air
https://www.businesstechweekly.com/online-sales-and-growth/s...
https://www.warehousingandfulfillment.com/warehousing-and-fu...