The research found, on average, 0.81kg of carbon dioxide was produced for each kilogram of milk in the 2010/11 season, compared to 0.75kg of carbon dioxide in the 2013/14 season and 0.78kg of carbon dioxide during the 2017/18 season.
Two international studies – published in 2014 – out of Australia and Ireland calculated 1.1kg of carbon dioxide was emitted for each kilogram of finished milk.
He noted the per-kilogram carbon footprint of milk used in the study was different to the total greenhouse emissions used in reports such as the Ministry for the Environment’s annual count.