I didn’t realise dairy made up such a large amount of purchases. Is this by weight, value or number? And is the disproportionate carbon footprint compared to meat just becuase we consume more of it?
AD is sometimes used by wastewater treatment works to treat the ‘sludge’ from sewage but it requires scale to be commercially viable due to throughput and the gas cleaning kit required. I’m not sure how prevalent farm slurry digestion is but some farmers just store slurry before using it directly on land, to replace fertiliser. Maybe the NFU or similar organisation keeps stats on it?
Looking at where dairy carbon emissions actually come from, the report in the link below has got some useful stats and stories on the carbon footprint of milk production (highlights below). I imagine cheese production increases this due to the additional processing.
The three major sources of GHG emissions were:
• Carbon dioxide emissions – derived from inputs of fertiliser, lime, herbicides, pesticides, fuel, electricity, straw/bedding and animal feed (26% of the average carbon footprint was due to concentrated feed use)
• Nitrous oxide – derived from fertiliser application, animal and organic manure management, sewage sludge (if applied), other crop residues and atmospheric deposition
• Methane – arising from enteric fermentation in the rumen (40% of carbon footprint) and, to a lesser extent, emissions from manure management.