I thought I would say a few words about the concept of “food miles”.

I thought “food miles” had already been debunked but a telephone conversation with one of my relatives in the UK made me realise it’s still alive, kicking and damaging.

My relative - an aunt - announced proudly to me that she had stopped buying food from New Zealand because of the “food miles”.

The theory behind her actions is that:

  • ships have to carry food a long way from New Zealand
  • ships burn lots of oil when they carry food a long way
  • burning lots of oil produces lots of carbon dioxide
  • carbon dioxide causes global warming

Therefore, to fight global warming, you clearly need to stop buying food from New Zealand.

This sort of argument, however, assumes that transport alone determines the carbon dioxide released in food production. Researchers at the University of Lincoln looked at the whole picture of food production - taking into account farm machinery, fertiliser use (fertilisers are made from fossil fuels), refrigeration, transport, etc and found:

  • The energy used in producing lamb in the UK is four times higher than in New Zealand (including transportation from New Zealand to Britain).
  • In general, New Zealand farmers tend to apply less fertiliser and animals are able to graze outdoors year-round.
  • Energy inputs for apple production in NZ are a third of those in the UK - in part because of lower greenhouse gas emissions from New Zealand electricity generation.
  • In dairy production, the UK produces 35 percent more emissions per kilogram of milk solid than New Zealand (including transportation from New Zealand to Britain).
  • Furthermore, the average overall energy ratio for New Zealand dairy production is lower than any reported overseas - 0.59 compared to an estimated 2.8 in the USA and a range of 0.67 to 2.4 in European countries. In other words 0.59 units of energy put into New Zealand dairy production yields 1 unit of food energy. Overseas, more energy is usually needed to produce dairy products than they ultimately contain - clearly an unsustainable situation.

Thankfully, in the last few months, overseas researchers have been clearly stating that “food miles” is a poor measure of efficiency.

From the Guardian:

“The idea of food miles is starting to resonate with consumers, but what we’ve found is the distance a product has travelled is important but so are lots of other factors across the chain,” says Euan Murray, strategy manager at the (UK) Carbon Trust.

“During our research we’ve seen that in some cases the distance travelled can be a poor indicator of a product’s carbon footprint, so just because something has come from abroad doesn’t necessarily mean it is worse for the environment.”

Dr Andrea Collins from the Brass waste and resources research centre at Cardiff University and Dr Ruth Fairchild, a nutritional analyst at the University of Wales Institute, Cardiff, agree that the food miles concept is too simplistic. They argue that their recent research into the environmental impact of food points towards a better system of “ecological footprint” analysis. This measures a food’s impact in “global hectares”, the notional land area needed to provide the resources to produce it.

The research concluded that, on average, only around 2% of the environmental impact of food comes from transporting it from farm to shop.

I’ve already pointed my aunt in the right direction and, I’m pleased to say, New Zealand food is now back on the menu in her home.

I just hope there aren’t too many other overseas homes where food from New Zealand is still off the menu because of a myth.