Carbon footprints in the New Zealand dairy industry: a comparison of farming systems

Abstract

Environmental indicators which measure the energy required to produce one tonne of milk solids under the production processes of the New Zealand dairy industry are available at the macro level. However, where intensification of the industry is occurring at different rates and different localities within New Zealand, using indicators which are based on national averages may not be the most accurate way of assessing the environmental impacts associated with dairy production. Further to this, where there is increasing scrutiny in export markets of the environmental impacts of dairy production processes, there is also an increasing reliance on information systems by consumers to assess these environmental impacts when purchasing dairy products. Macro level indicators may no longer be credible where there is increasingly disparity in the production processes of the New Zealand dairy industry. This research used Life Cycle Analysis to estimate the energy requirements and associated carbon dioxide emissions for dairy production under three different management regimes at the farm scale. The three farm management scenarios were defined to represent the intensification and expansion which has occurred within the industry over the past decade. Scenario One represented a production system which was typical of dairy farming in the Canterbury region. The second Scenario was modelled on production under a management regime which used conventional dairy farming practices and was located in the Mackenzie Country. Scenario Three was also located in the Mackenzie Country but used a farm management regime which was supported by housing the milking herd in a “herd home” for the majority of the year. Although the current format of industry knowledge precluded quantifying all the crucial variable and linkages within the specific farm management regimes, the conclusions drawn from the analysis were that the total quantity of primary energy required to produce one tonne of milk solids is increasing as the production processes intensify within the New Zealand dairy industry; and subsequently, developing credible indicators of energy use at the farm scale would enable the dairy industry to participate in the eco-labelling information systems in export markets.