There is one additional contributor to embodied emissions: distribution. This includes the emissions generated when transporting cloud hardware from the manufacturer to the data center, and from the data center to disposal. Calculating accurate emissions associated with distribution is essentially impossible, because there is no way to measure the distance or mode of transport between the specific factory that produced the hardware components, and the specific data center that a customer’s instance is based in. Therefore, Tailpipe does not account for distribution in its embodied emissions methodology.
Our rationale for this comes from an assessment of the limited data sources available concerning data center hardware distribution. The best estimation of the GWP impact of distribution on data center hardware comes from the Dell R470 Life Cycle Analysis. Dell calculates that transport from manufacturer to data center accounts for just 0.06% of the total GWP of a server manufactured and installed in the US, and just 0.03% for the same in the EU. Dell calculates two separate use cases for distribution because of the difference in regional transport networks that prevents Tailpipe from being able to calculate accurate emissions associated with distribution. The 2-fold difference between the US and EU figures demonstrates why Tailpipe does not believe distribution’s CO2e emissions can be accurately estimated with the available data. In addition, the overall contribution of distribution from manufacturer to data center is essentially negligible, at less than 0.1%. In addition, Dell itself underscores the unreliability of its distribution figures by not expanding upon them within its Results, as it does do with manufacturing, use, and end of life.
As an example, to apply a distribution figure to the worked example in Calculating Total Embodied Emissions of Manufacture, we must first create an average distribution factor of 0.045% of the total instance GWP. This is the average of Dell’s US and EU factors. We can apply this to the GWP of the c6gd.medium instance:
0.00045 * 22.02 = 0.0099 kg CO2e
Tailpipe considers this quantity of emissions to be negligible, and the data source too unreliable to incorporate into its methodology. It continues to assess the available data and hopes to incorporate distribution into the methodology once more reliable sources have been published.
