Model to measure methane emissions needs to change

Smith, respected as an agricultural scientist, farmer and politician, says the present system of measuring methane emissions by way of an accounting target approach is wrong. He says no one questions the need for emissions to be reduced, but he says the present system will one day end in tears.

"What needs to happen is a complete change in strategy internationally for methane emissions from animals, with the focus being on the 'carbon efficiency' of the food that we produce," he told Rural News.

Smith says NZ has got to start lobbying the United Nations Intergovernmental Panel on Climate Change (IPCC) to start looking at food production differently. He says shifting the focus to the carbon efficiency of food being produced and ensuring it's produced in the most carbon efficient way will benefit climate change. "Even if NZ alone decided to change the focus to carbon efficiency in food, this would make little difference. What NZ must do is get out there and influence global thinking on the subject and get buy-in from other countries," he says.

According to Smith, some of the solutions being proposed for reducing methane in our livestock - such as vaccines and boluses - are not as good as they sound. He points to the problem that worms in animals are developing resistance to drenches and believes the same could happen with things like vaccines.

He says NZ has ways of farming that are so much more efficient and notes that the big challenge in carbon efficiency is to make sure that more of what a ruminant animal consumes goes into production compared to the maintenance of the animals' body.

"That's what delivers efficiency," he says.

One way of improving carbon efficiency on NZ farms says Smith is to slaughter beef animals much sooner than we do. He says now too many 'old' animals are being slaughtered and keeping a cattle beast for three years is not workable if you want to increase carbon efficiency.

"Why not slaughter a beast at 18 months? That would make a huge improvement on carbon efficiency," he says.