Yorkshire farm vet Miles Middleton NSch 2022 has published his Nuffield Farming report entitled 'Counting Carbon; Does a Smaller Footprint Leave Less Impact? Defining Sustainability in the Dairy Sector', sponsored by the Yorkshire Agricultural Society.

The full report is now available on the Nuffield Farming report library. Miles presented the findings of his report at the 2023 Nuffield Farming Conference in Exeter. A recording of his presentation is available here.

As part of his Scholarship, he travelled to the USA, Ireland, the Netherlands, and France. He aimed to understand how sustainability can be defined in the dairy sector and reflect on what this could look like in the UK.

"In the dairy sector, due to highly complex biological production systems, multiple outputs, use of co-products and relatively abstract components such as indirect land use change, there is significant opportunity for methodological divergence when calculating carbon footprints of milk," Miles says in his report.

"Layered on top of this are debates around accounting for soil carbon sequestration, the application of carbon off-setting as well as the carbon equivalence of short-lived greenhouse gasses."

During his study, he established that the key factor that drives carbon footprint in the dairy industry is feed efficiency.

"High output, confinement dairy systems almost without exception feed higher levels of concentrate to cows, making the ration more digestible and leading to higher milk output. In broad terms, this results in a lower carbon footprint per litre of milk when compared to more extensive grazing systems."

However, he notes that this is often at odds with how experts define a resilient and sustainable dairy sector.

"Livestock systems can play an integral role in restoring and maintaining natural capital, but what is perceived as the highly intensive nature of dairy farming frequently presents barriers to this and presents risk of environmental damage.

"Driven by the pursuit of efficiency, agriculture has seen a seismic and ever accelerating shift towards larger, higher yielding, more specialised farming systems with greater dependency on non-renewable resources, purchased inputs and capital assets.

"Through capital interest, depreciation and asset costs, these systems carry increasing levels of fixed costs, driving the necessity to maximise output even at very low marginal profitability, and frequently at very low marginal efficiency."

 Study objectives

Reflect upon and interrogate the sustainability goals which define the contemporary discourse

Messages

1. A carbon footprint is as much subjective as it is objective. Methodological choices can allow results to be tailored by the author to support different opinions.
2. Carbon foot-printing is essentially a metric of efficiency, describing the carbon input required to produce a standardised unit of output. In relation to the dairy sector, overall feed efficiency is the key driver of divergence between farms.
3. A drive for carbon efficiency is, broadly, a drive for larger, more intensive, more technically efficient dairy farms - usually with a greater dependency on arable products, purchased inputs and debt.

Consolidation and intensification present many challenges, both from the perspective of environmental protection, as well as wider fragilities of these systems in the face of future climatic, political, and social challenges.

While efficiency and sustainability may not be concepts diametrically opposed, they should not be conflated. Sustainability is a far broader concept.