No, your steak and chops are not carbon-neutral: ministry

Government scientists have busted research claims that meat farms are near carbon-neutral.

One study – funded by Beef + Lamb – found that trees on sheep and beef farms are sucking up 63-118 per cent of the greenhouse emissions produced. But a new Ministry for the Environment report, released yesterday, found the figure was closer to 33 per cent. The disputed number could have financial consequences for farmers. From 2025, farms are being asked to measure, reduce and potentially pay for their emissions – the methane burped out from animals plus the nitrous oxide produced in the soil.

Beef + Lamb said this equation should also subtract any carbon dioxide absorbed by vegetation on farmland. The ministry report found several faults with the industry study, which was authored by Auckland University of Technology researchers and peer-reviewed. First, it did not account for the trees being chopped down each year. Since more than 11,000 hectares of farmland are deforested, harvested or cleared each year on average, the ministry report factored this into its calculations.

The Beef + Lamb-backed research also over-estimated how much carbon was absorbed by native and exotic shrubs and scrubland, the report concluded. Ministry for the Environment senior analyst Nigel Searles said the industry study used carbon absorption rates from some small-scale research on scrubland. In comparison, the ministry measured the amount of wood at sample sites across the country, and worked out how much carbon was stored.

Compared with the permanent and commercial forest, scrublands absorbed minimal amounts of carbon. If scrubland is newly established, it sucks up some carbon dioxide, the report explained.

However, nearly 90 per cent of all this land is wellestablished and in a steady state, therefore is not absorbing additional carbon. The same is true for older plantations. Unlike the industry study, the ministry’s count also included the carbon released from farms located on drained wetlands. ‘‘When you drain wetlands, it slowly emits carbon into the atmosphere and the only way to reverse that is to reflood or restore wetlands,’’ Searles said.

He acknowledged the industry study was the first of its kind, though flaws had been identified.

The work would help the He Waka Eke Noa partnership between the agricultural industry and government, Searles added.

‘‘A key part of that thinking is how to recognise and to what extent do you recognise on-farm vegetation.’’ The ministry report found that vegetation and drained soils on farmland absorbed nearly 5.5 million tonnes of carbon dioxide in 2018 – equivalent to a third of the agricultural emissions produced by the meat industry that year. That means that, if farmers become subject to a carbon price on their net emissions, the trees on their land could offset a proportion of the methane and nitrous oxide produced.

But if the calculations from the ministry report become the standard, it will be a lot less than previously thought.