Scottish dairy supply chain GHG report published

The Scottish Government has published the findings of research it commissioned into GHG emissions arising from the dairy supply chain in Scotland.

The aim of the research project was to assess global greenhouse gas ( GHG) emissions associated with Scottish dairy supply chains, in order to identify the main opportunities to reduce emissions while maintaining or improving economic productivity.

The specific objectives were to:

• Describe key inputs to and outputs from Scottish dairy supply chains
• Summarise methodologies to estimate GHG emissions, and scope out available data
• Assess GHG emissions associated with each dairy product supply chain in Scotland
• Identify opportunities to reduce GHG emissions across all products

Product carbon footprints were undertaken for six major Scottish dairy products. Grass-to-farm gate emissions dominated most of the life cycles but some products had significant GHG burdens downstream of the farm stage e.g. yoghurt and ice cream. This was principally because they use more packaging per kg of product or require significant amounts of chilling.

Total greenhouse gas emissions associated with the production of 1.3 billion litres of milk on Scottish dairy farms in 2007 was 1.5MtCO 2e - or 1.1kgCO 2e/kg of milk (1.2kgCO 2e/litre of milk). Additional emissions associated with the processing, distribution and use of the six dairy products studied in this project was a further 0.25MtCO 2e.

Total cradle-to-grave dairy supply chain emissions were 1.7MtCO 2e for the six products studied - equivalent to 3% of Scotland's direct GHG emissions. In more detail:

• The production of feeds (pasture, silage and concentrates) accounted for approximately one third of dairy farm emissions. Emissions associated with soya production (in particular land use change in Brazil and Argentina) accounted for 5% of total dairy farm emissions.
• The cheese manufacturing by-product, whey, contains approximately 13% of the milk dry mass produced by Scottish dairy farmers. Its fate and utilisation is currently not clear - with a significant proportion potentially being disposed of as waste. Total whey production contains 8,000 tonnes of crude protein or 350,000MJ of energy. This is roughly equivalent to 15,000 tonnes of soybean meal. To put this in context, it is estimated that Scottish dairy farmers use 19,000 tonnes of soyabean meal in dairy rations each year.

The report’s recommendations are as follows:

On farm

It is recommended that farm emissions should be the focus of collaborative supply chain mitigation activities if the most reductions are to be realised:

• Support sustainable improvements in cow productivity through health, breeding, husbandry
• Continue focus (though existing initiatives) on improved fertilizer and manure management
• Optimise and support improvements in sustainable animal nutrition
• Improve farm energy efficiency - in particular farm vehicle diesel and parlour electricity
• Support new small-scale, on-farm anaerobic digestion
• Explore potential of setting-up supply chain-level initiatives and funds to pay for on-farm mitigation initiatives which deliver opportunities highlighted above.

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Processing
• Reduce emissions associated with product packaging through lightweighting, material substitution and/or the development of novel forms of packaging system.
• Reduce energy consumption associated with the processing of milk to dairy products (in particular liquid milk and cheddar cheese)
• Fully utilise all co-products (in particular whey) to ensure as little milk dry matter is wasted and the product carbon footprints of principles products (e.g. cheese) are minimised
• Support research, and explore opportunities, to understand and communicate the environmental impact of dairy products in relation to nutrient density

Retail

Dairy products, apart from milk, enter conventional distribution networks and so industry-wide efforts to improve freight efficiency and decarbonise chilling processes will benefit dairy products as well.