Bringing It Home: Is It Greener to Ship or Buy At the Store?

I can usually hear my neighborhood delivery driver coming down the street before he gets here, which isn’t such a bad thing, considering that my doorbell doesn’t always work and I hate to miss a delivery. But the sound of that diesel lumbering down the street every with all that stopping and starting, makes me wonder how much fuel these things use. Then I think about the thousands, or is it millions of trucks that are running around the country and wonder what that carbon footprint must be.

That got me to wondering– when I order an item online and have it delivered to my home, is that greener or less green than going to the store myself and picking it up. After all, my car is pretty efficient and I know it gets better mileage than those delivery trucks do.

In both cases, the item starts at the factory, then it goes to a warehouse (let’s assume it’s newly produced) and  then it ends up at my house. The question is what happens in between.

I decided to look into this. Fortunately I wasn’t the first one to ask this question. A study conducted by Carnegie-Mellon’s Green Design Institute found that e-commerce used less energy and had a carbon footprint that was one-third less than your traditional brick and mortar business.

Of course, your mileage, may vary as the EPA ads like to say. Obviously, if the store is just around the corner from you and you can walk there, you will use less energy (make note urban planners). But the CM study found that statistically speaking, shoppers drive an average of 14 miles round trip, in an average car, every time they go shopping and pick up three items while they are out there. If you crunch the numbers as they have, you’ll find that the UPS truck, despite its larger engine, uses less fuel per package, because it delivers so many packages in a relatively small area.

There are downsides, however. For example, products delivered directly to your home require extra packaging, sometimes a lot of extra packaging, but that is generally not enough to tip the scale in favor of traditional retail

Of course, there are other reasons to shop in a store and I don’t mean to suggest you shouldn’t do so, but if you wanted to know which has a bigger footprint, now you know, at least according to this one study.

However, another study by Britain’s Newcastle University comes to the opposite conclusion. Why? This study includes the controversial rebound effect or the Jevons Paradox, which states that when you make something more efficient, people will use more of it, thereby negating some portion of the benefit. Phil Blythe, who chaired the committee that chaired the report stated, “Policy makers must do their homework to ensure that rebound effects do not negate the positive benefits of their policy initiatives and simply move carbon emissions from one sector to another.”

According to the Newcastle study, it would require a shopper to order 25 items online at a time in order to break even with the retail shopping experience from a carbon emissions perspective if the rebound effect is taken into account.

Experts agree generally, that there might be some reverse efficiency effect, though most believe that it is quite small and very difficult to quantify. Others, like the Breakthrough Institute, not only believe that rebound is significant, but that in some cases, it might even exceed the original energy savings, a phenomenon known as backfire. In my opinion these theories have been repudiated, but you can read about them and decide for yourself.

A third study, conducted by the non-profit Center for Energy and Climate Solutions says the e-commerce is far greener. In fact, they say that it is 40% greener, even if you ship (two 20 pound packages) by overnight air, the most energy intensive method of all. If you use the more popular ground shipping option, that will use only one-tenth as much energy.

These numbers are lower because they not only look at transportation, but they also look at the retail store itself, which had to built and lit and heated, with all those windows and doors. Based on their calculations, your two 20-pound packages as part of a full trailer load, shipped from 1000 miles away, would only account for about one-tenth of a gallon of gasoline, while your drive to the store would likely require much more than that if you have to drive more than six to eight miles to get to the store. Once again your mileage will vary.

In the meantime, delivery companies like UPS are continuously working to improve their efficiency, which goes straight to their bottom line and makes the online purchasing choice even more favorable.

What is the ideal answer? Buy less and buy local if you can. Clearly something that is produced locally is going to require less energy to bring home, whenever that is possible. If that’s not possible, then do your homework and be sure to select the most efficient producer and delivery company, which will be another story covered later in this series.

[Image credit: Delivery: Gracias: Flickr Creative Commons]

RP Siegel is the co-author of the eco-thriller Vapor Trails, the first in a series covering the human side of various sustainability issues including energy, food, and water.  Like airplanes, we all leave behind a vapor trail. And though we can easily see others’, we rarely see our own.

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