Have you ever wondered about the carbon footprint of your shopping habits? Is online shopping better for the environment than brick and mortar shopping? There are many studies on the subject and there are myriad factors to consider when answering these questions. To try and make this process a little easier, we have pulled together existing research and have developed a guide to reducing your carbon footprint this holiday season.
One 2013 study by MIT looked at the impact of online vs. in-store shopping for a few items (a t-shirt, a Barbie Doll, and a computer) and concluded that a few key factors can tip the scales in either direction. While this study ignored the impact of the embodied carbon of these items (more on this later), let’s look at the biggest factors that could contribute to your holiday shopping carbon footprint and factor into the store vs. online debate.
Most studies will tell you that generally online shopping has a smaller carbon footprint than in-store shopping. The main reason for this is related to personal transportation – the average American is more likely to produce more carbon traveling to pick up their single item than the impact of the freight shipping and delivery to your door. The main reason for this is because shipping companies are very efficient, and their emissions are often divided between many packages at one time. Meanwhile, you are likely expending a good amount of carbon by driving to a store to pick up only one or two items. What if you have an electric car or you are walking to the store? What if you choose expedited shipping when online shopping? Well, these all change the equation.
While this may be surprising to some, the next big factor is packaging. For online shopping, this will likely be the single biggest portion of your carbon footprint (other than the embodied carbon of the item). The additional packaging required for shipping for each individual item will have close to six times the carbon footprint as in-store packaging will according to the MIT study.
All purchases require some amount of freight transportation – for an in-store purchase this means the truck that came to the store to re-stock that item. For an online purchase, this means the truck or airplane + truck that delivered your item to the distribution center. For in-store purchases, this is a very small portion of the carbon footprint of the item because items are likely re-stocked in bulk in a relatively efficient way. For online purchases, items are transferred to distribution centers as needed and in the case of expedited shipping, may include air shipping. The addition of air shipping could result in four times the carbon for freight transportation and pushes online shopping over in-store shopping as the more carbon hungry option (assuming only one trip to the store).
While you might think that someone delivering a package to your door is no different than you picking it up, this is not the case as far as carbon footprint. That delivery man is likely delivering lots of packages and is directed by algorithms to increase efficiency at every turn. Some delivery companies even have trucks drive together to reduce drag or automatically alert each other to traffic slowdowns to minimize braking (see Vox article below). This all results in a delivery using less carbon per package than you in your car (oh you’re not driving – good job).
Store Energy Use:
The MIT study also calculated the energy use of the warehouse, sorting, collecting centers and retail stores and the contribution that should be accounted for when purchasing an item. Although this is not a large portion of the equation per item, it is not insignificant.
Computer, Data Center, and Information Flow:
Finally, the carbon attributed to the energy consumption from your computer, as well as the servers, when searching and purchasing online is relatively insignificant in comparison to the packaging and travel portions. Similarly, the carbon attributed to creating packaging labels and transmitting information was also found to be insignificant.
While the results from this study provide useful information for deciding between online or in-store shopping, if we really want to get serious about considering the impact of our shopping, we need to consider the embodied carbon of the items being purchased. Every new item that is produced requires a countless number of products to be manufactured, shipped around the world, and assembled before making its way to the store or warehouse. The carbon required for these processes is difficult to calculate, but should not be overlooked. Fortunately, one item used in the MIT study has been the subject of a detailed life cycle analysis – the Barbie Doll. A team from the California College of the Arts Design Strategy program determined one Barbie is responsible for about 3.2 cups of oil, or about 2 kg of CO2 equivalent (kgCO2e). Combining this with the findings of the MIT study reveal one very important takeaway – if you really want to reduce your carbon footprint, buy gifts that are used!
The different cases that were studied in the MIT report focused on three portions of the shopping process referred to as “search,” “purchase,” and “return,” Looking at differences in these three portions results in many different possible cases (including three that we have added to account for the purchasing of used goods – a.k.a. the “Thrift Store Shopper”). The table below shows how these cases break down:
In-Store Shopper: This person only shops in a store, but either drives to multiple stores, drives to one store, or walks/bikes to one store.
In-Store Search, Internet Purchase: This person goes to a store to compare prices, but ultimately purchases online and returns online.
Internet Shopper: This person does all their purchasing and returns online, but may choose regular or expedited shipping.
Thrift Store Shopper: This person only buys used goods in thrift stores.
While the study includes a wide range of variation in the input variables, the graph below shows the results of one snapshot – the average for an urban area purchase of a Barbie Doll with embodied energy included and three “Thrift Store” options added.
So, walking to a thrift store to buy a used gift that has no packaging is your best option by a considerable margin. Is this a surprise? Maybe not. Then why aren’t we doing it more often?
In summary, here are some tips for reducing your carbon footprint this holiday season:
- Avoid expedited shipping:
- This increases the chance of air shipping and reduces efficiency overall.
- Bundle items together:
- This will reduce the carbon footprint per item purchased for transportation as well as packaging.
- Recycle packaging:
- It’s tempting to just crumple it all up and throw in the trash – separate it out and put it in the correct bin!
- Walk to the store:
- You’ll get some exercise!
- Buy used goods!
- Ever been to a thrift store?? They’re a blast!
Good article summarizing online vs. in-store purchasing:
Barbie Doll Research:
Article on efficiency in trucking for shipping and why 2-day shipping is bad:
By Chris Hamm, Building Systems Engineer