I have been reading up on the carbon foot printing work lately. A lot of interesting findings. Overall, my impression is that the modern e-commerce is not significantly improving our carbon footprint. And with customers’ adaptive behavior (e.g., ordering more, not giving up store trips), it is likely that we can end up with a larger carbon footprint, and a larger variability too.

Let me explain this using an piece of good work done in a Master’s thesis at MIT. Its author Dimitri Weideli wrote in 2013 his thesis titled “Environmental Analysis of US Online Shopping“, where he documented details on calculating carbon footprint for the supply chain.

First, let’s look at the big picture:

Source: https://ctl.mit.edu/sites/default/files/library/public/Dimitri-Weideli-Environmental-Analysis-of-US-Online-Shopping_0.pdf

Right there, we can see the main message: pure online shopping (i.e. cybernaut) has a slightly lower (1.4 kg of CO2e vs 1.6 kg, so about 13% lower) carbon footprint, but the moment you add fast delivery to online shopping (cybernaut impatient), its carbon emission is actually greater than traditional shopper.

It is also interesting to see the different composition of carbon footprints. In traditional shopping, consumer transportation is the single largest source of CO2 emission. But in online shopping, it was packaging.

Secondly, the author conducted a simulation study to see the impact of those different parameters around shopping. The list of variable inputs includes:

Source: ibid

All those variabilities lead to a very wide range of outputs:

There, another important insight emerges – online shopping tends to have less variation because online orders are “fulfilled by a more controlled and efficient parcel delivery system”. And overall, online shopping tends to be more carbon efficient, but not by much.

Note that in here the author uses data of shopping for a toy. Results should be different for other categories, especially groceries. As I have discussed in an earlier post, groceries tend to have more items per order, and they can be delivered in dedicated grocery vans (as opposed to parcel delivery systems). As a result, online shopping could be much more carbon-efficient.

Also, just for comparison purposes, here is the emission factors used: