Data Sheet 1_UK land use implications of replacing dairy farming with precision fermentation.docx

Reducing animal agriculture is key to releasing land needed to achieve global environmental goals. Precision fermentation (PF) is a technology which uses genetically engineered microbes to produce ingredients such as dairy proteins. Few studies have quantified PF’s land-sparing potential. Using the UK as a case study, we assess the land use implications of scaling up the production of PF milk (plant-based milk containing PF dairy protein), by calculating and summing land footprints (area/mass) of PF milk’s individual components. PF milk’s land footprint was estimated to be as much as 96% lower than that of cow’s milk. Replacing 20%, 50% or 100% of UK-produced cow’s milk with PF milk was estimated to release 859 kha, 2,147 kha or 4,294 kha of land by 2050. This corresponds to 40–202% of required permanent grassland and 16–82% of required cropland to meet the UK Climate Change Committee’s 2050 ‘Balanced Net Zero’ targets regarding afforestation, bioenergy, peatland restoration (lowland grassland only), agroforestry and hedgerow creation. These results suggest PF could play a critical role in releasing land for net zero measures and alleviating land use pressures in the UK and globally. Further research is required to address knowledge gaps and facilitate more nuanced assessments of PF’s land-sparing potential.