New measurements of the "carbon footprint" of New Zealand apples sent to Europe show that 1kg of braeburn or royal gala apples will generate nearly their own weight in greenhouse gases.
Over half of the global warming potential comes from the shipping used to take them to Europe.
When the pipfruit's carbon footprint from being grown on the orchard to being delivered to the supermarket shelf is measured by the British national standard, PAS 2050, 1kg of apples produces the equivalent of 900g of carbon dioxide.
Measured according to the broader ISO 14040 standard, which also takes account of the emissions from consumers taking the fruit home, and disposing of the waste, lifts the emissions from 1kg of apples to the equivalent of 1.2kg of carbon dioxide.
Similar figures for the same fruit sent to Asia, were 700g (PAS) and 920g (ISO) and for the west coast of the United States: 700g (PAS) and 930g (ISO).
The progress of the apples through the orchard, packhouse and port contributed between 15 percent and 19 percent of the total carbon footprint, and shipping emissions accounted for 54 percent to 57 percent of the footprint.
A similar study on Fonterra's New Zealand milk showed each 1 litre equivalent sent to Europe generated 940g of carbon dioxide – about 85 percent of it on-farm.
Pipfruit New Zealand chief executive Peter Beaven said the eight-month apple study has provided a model which the NZ growers are willing to make available to other pipfruit-producing countries, starting with growers and exporters in the Southern Hemisphere.
"We want to offer it to others in the hope that we can agree on common standards on how to measure emissions across the life-cycle of the apple – from orchard right through to consumption," he said.
While the actual numbers were important, the key for the industry was to identify "hot spots" where reductions could be made.
"Only 9 percent to 14 percent of emissions come from growing and packing (NZ apples)," Mr Beaven said. "The balance is from shipping, retailer repacking, distribution and consumer use and disposal."
Though only 7 percent to 10 percent of the emissions could be blamed on the production system, improved management of chemical spraying could reduce orchard emissions by 20 percent and save costs of $80/ha.
And participation in the "apples future" programme to produce export fruit with no detectable levels of pesticide residues could reduce emissions by about 10 percent and save costs of up to $140/ha.
Investing in better refrigerated storage, and reduction of electricity use could cut emissions by between 10 percent and 25 percent and save costs of up to $8.10 for each pallet of apples.
Implementing all the most feasible short-term orchard reductions requiring minimal capital investment could lead to cost savings of $650/ha.
Mr Beaven said there was considerable potential for reducing emissions from shipping, including better use of ship capacity, slower shipping speeds, improved efficiency of refrigeration and new ship designs.
The study was a joint project between Ministry of Agriculture and Forestry and the New Zealand pipfruit industry, and research providers including Landcare Research, Plant and Food Research, AgriLink and Massey University.
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