A Welsh scientist who has studied the food miles debate says the distance that food has to travel to market is largely irrelevant in establishing the carbon footprint of food products.
Gareth Edwards-Jones from Bangor University, who is on a speaking tour of New Zealand, says other factors play a far greater part in determining the energy used, such as how food is grown, processed and transported.
He says the way food is cooked is significant, as the energy used in the kitchen can be greater than that used in every other stage up to that point.
Mr Edwards-Jones isn't yet prepared to buy the argument that New Zealand lamb shipped to the UK has a lower carbon footprint than lamb produced in Britain.
He told Saturday Morning that factions in both countries are making their own decisions using different research methodology, so the science is unproven.
Gareth Edwards-Jones says argument in favour of New Zealand apples shipped to the UK is probably true only or about two months a year, during July and August, when the carbon footprint for locally grown fruit doubles because it comes out of cool stores.
Irrespective of which way the food miles debate goes, Mr Edwards-Jones does not think New Zealand food exports to the other side of the world are under threat.
He says New Zealand has a positive image, good technical farmers and good processes, and most produce is being exported by ship which is has a much lower carbon footprint that air-freighted goods.