CO2 Share: Walmart Vs Small Store

I am still not convinced about the impact of CO2 emissions on global climate change. However I decided to do a comparison of CO2 footprint of Walmart vs small stores. Since there are so many discussions around supporting local mom and pop stores vs. big box retailers, I wanted to do a comparison of these two along just this one dimension (commemorating the Earth week). To make it an even comparison I used CO2 tonnes per dollar of sales and per employee.

I assumed that the retail stores are on the average 4000 square feet and owned one car driven for 20,000 miles for business purposes. Since no free calculator for small business is available, I used an estimate that mirrors an household of similar size and people. Hence I underestimated the electricity spent on large refrigerators, continuous lighting, store display signs and the CO2 impact of distribution of goods to the stores.

For Walmart, the published data says $19.2 million tonnes and it includes all their trucks, corporate jets, stores and corporate offices.

The total US retail sales is $4.2 trillion (retailindustry.about.com).
The single stores' share of total retail sales is 50% (same source).
US Census data says, the number of retail stores with less than 10 employees as 796,000. These numbers give a very high annual per-store sales (about $2 million). This should be treated as an overestimate of actual numbers.


Here is the comparison. On a per dollar sales, Walmart looks about 50% as bad. On a per employee basis, Walmart is way better.

Caveats:

1. For small stores, the CO2 footprint is underestimated and the annual sales numbers are overestimated.
   
2. Walmart's numbers include the entire corporation and non retail related activities.
   
3. Walmart has large economies of scale and can ride their experience curve to make large positive impact on their CO2 footprint.