Experts criticise NZ dairy report

By Sarah Britton

- Last updated on GMT

Related tags: Greenhouse gas emissions, Greenhouse gas, Nitrogen

UK dairy experts have slammed a study claiming the UK’s dairy production system causes significantly more greenhouse gas emissions than New...

UK dairy experts have slammed a study claiming the UK’s dairy production system causes significantly more greenhouse gas emissions than New Zealand.

Comparative energy and greenhouse gas emissions of New Zealand’s and the UK’s Dairy industry, by Lincoln University, NZ, follows an earlier paper it issued last year. It claims UK dairy production leads to 34% more emissions per kg of milk solids and 30% more per hectare than NZ for dairy production.

However, Donal Murphy-Bokern, independent consultant and former head of DEFRA’s (the Department for Environment, Food and Rural Affairs’) Agricultural Climate Science division said: “The biggest uncertainty results from motor fuel usage.” The data may have included fuel for personal use, or other non-dairy use, he explained.

Lincoln University’s report also highlights the high greenhouse gas emissions of nitrogen fertiliser, which many UK farmers depend on. But researchers had not accounted for nitrous oxide emissions from biological fixations, such as clover, which is commonly used in NZ, said Murphy-Bokern. “The application of national accountancy levels needs to be looked at in order to make a true product comparison.”

Dairy UK technical director Ed Komorowski said: “All these things are open to subjectivity and the people sponsoring the studies have a specific objective, so it risks being biased.”

Tara Garnett, co-ordinator of the University of Surrey-based Food Climate Research Network, added: “If there’s so much disagreement between the UK and NZ regarding dairy emissions, then transport isn’t the issue; it’s about the high greenhouse gas intensity of livestock production.”