My wife and I were wondering about the energy differences between Amazon delivering our packages (along with all their customers), vs the fuel efficiency of all of us traveling to different stores and personally buying our stuff.
We know less cardboard boxes would be used if we made in person purchases, but what about the fuel usage between Amazon delivery and the individual fuel usage? Of course I do mean cumulative usage for all individuals vs Amazon usage.
The cardboard box usage might not be as much smaller than you think. Amazon presumably gets huge shipments of books using fewer boxes than shipping to individual warehouses and the individual bookstores. If you get a paper or plastic bag at the store, that, too is eliminated.
The travel calculation seems easy to me. If a single truckload of Amazon boxes presumably sorted to be sent around the same general neighbourhood, were replaced by people driving to assorted malls, that would consume a lot more gas in total. One electrified Amazon truck would go even farther to reducing the fuel difference. The only counter-argument might be that people still make that trip anyway, they just pick up less items.
The facts on this are going to be hard to wring out of the data, which is likely very noisy. For any given customer or group, it’s going to depend on how dense the customers are, where their stores are, what their shopping patterns are, etc.
Even if we just look at gas, and ignore vehicles, cardboard, etc. it’s pretty hard.
What you kind of want to do is measure the fuel consumption of a large group of customers before they became Amazon customers, then their fuel consumption + Amazon’s (or FedEx or whatever’s) consumption delivering in that area.
But even that data (if you could get it, which you probably can’t) wouldn’t really answer the question. Like, let’s say that I become an Amazon customer, and my fuel consumption while shopping goes down more than the marginal delivery fuel consumption goes up. Which sounds like a win for environmental efficiency. But I also have more free time because it takes less time to click on a website than to drive to some stores. And maybe I spend that time driving places and doing things? So my measurable fuel consumption might not change much, which would look like a loss for environmental efficiency. And you could probably make an argument either way that my excess fuel consumption doing something else should or should not count against Amazon in terms of net environmental impact.
OTOH, your free time could mean you spend longer at the gym or on the golf course, thus not increasing the overall miles driven (except with the 5-iron). You can as you point out hash over secondary effects til the cows come home…