Making sense of farm emissions
A tool which compares farm emissions to flights to London could help farmers better understand their carbon footprint.
Lincoln University’s farm carbon footprint calculator uses details like farm size, stock numbers, fertiliser and fuel use to calculate emissions of methane and nitrous oxide. The results are given as total CO2 equivalents, as well as the distance travelled by car and the number of flights from Auckland to London it would take to produce the same emissions.
Developed by the Agribusiness and Economics Research Unit (AERU) at Lincoln and engineering consultancy Agrilink NZ, the calculator was first launched in 2008 to add weight to the food miles debate. It has now been updated to give farmers a quick estimate of their carbon footprint and an idea of the area that could be planted to offset emissions.
Although the dairy industry accounts for 46 per cent of total agricultural emissions, Agrilink NZ managing director Andrew Barber said the calculator could be used by owners of many farm types.
That included horticulture, where farmers may not have access to detailed carbon footprint tools. ‘‘They, like all farmers, can enter their energy use, as well as that of their contractors, to better understand their carbon footprint,’’ he said. About 43 per cent of New Zealand’s greenhouse gases are caused by methane, burped out when sheep, cattle and deer ‘‘chew the cud’’. Nitrous oxide accounts for 11 per cent and is released from urine patches in paddocks, dung produced during grazing, manure spread on pasture and from nitrogen fertiliser.
Although Lincoln’s calculator was believed to be the first its kind in New Zealand at its launch, farmers have several other tools available to help them set emissions benchmarks and targets.
Industry modelling tool Overseer uses stock numbers, supplementary feed use, fertiliser applications and other farm practices to calculate nutrient loss and greenhouse gas emissions.
The link between the two was highlighted in a recent pilot project run by Fonterra and AgResearch as part of the Dairy Action for Climate Change plan. The project involved 100 of the dairy cooperative’s suppliers and found many of the steps being taken to protect rivers and streams also contributed to a reduction in on-farm emissions.