Rediscovered this Sankey diagram in a 2011 project report ‘Scottish Dairy Supply Chain Greenhouse Gas Emissions’ (Sheane, R., Lewis, K., Hall, P., Holmes-Ling, P., Kerr, A., Stewart, K., Webb, D.: Identifying opportunities to reduce the carbon footprint associated with the Scottish dairy supply chain – Main report. Edinburgh: Scottish Government, 2011).
Flows are in megatonnes of CO2-equivalents (Mt CO2e) greenhouse gas emissions (GHG) in 2007 related to the production of milk and dairy products in Scotland.
A total of 1.657 MtCO2e GHG emissions were caused along the dairy supply chain emissions, which was equivalent to 3% of Scotland’s direct GHG emissions. With a yield of 1.3 billion litres of milk on dairy farms in Scotland in 2007 this corresponds to 1.1 kgCO2e/kg of milk or 1.2 kgCO2e/litre of milk.
If you look at the origins of the emissions in the diagram you will see ‘enteric fermentation’ (aka ‘cow fart’) and liquid manure (‘cow poop’) as the main causes.
Read the full report here.