Have you ever wandered around Tesco and wondered the mathematic principles behind how all this yummy food got there? No me neither, usually I’m thinking about what delights I am going to have for dinner.

However, a recent discovering mathematics workshop got us thinking about the fundamental maths behind the global food chain.

I have often seen campaigns for food being sourced locally and local shops pushing for produce to be bought from them because it is better value for money or better for local business. So the question is, is it better to buy food sourced locally or from elsewhere around the globe? There are two things to be considered when answering this question, 1. climate change and 2. money.

As discussed in Richard’s workshop a study into local lamb and New Zealand lamb was carried out in 2006 by Saunders, the findings were:

Comparison of energy used and CO2 emissions between NZ and UK Lamb.

The energy used in producing lamb in the UK is four times higher than the energy used by NZ lamb producers, even after including the energy used in transporting NZ lamb to the UK. Thus, NZ CO2 emissions are also considerably lower than those in the UK.

As we can see from the study CO2 emissions are lower in producing lamb in New Zealand than the lamb produced in the UK and the energy used is higher in the UK than New Zealand. However that is not the only factor to be considered, of course another question when asking if food is better sourced locally or from around the globe is how cost effective is it?

This is where the fundamental maths comes into play. To save on energy and create less CO2 emissions the lamb will have to be transported from New Zealand to the UK. Some mathematical principles to be considered when transporting the produce:

• Mass (weight) – How much meat can actually be transported. There are weight restrictions for lorries, trucks and aircraft.
• Distribution of mass (density, centre of gravity) – Making sure the weight is distributed evenly wether this be in an aircraft, by road in a truck or shipping the produce.
• Size (bulk, length, height, depth) – Making the most of the space you have, there is no point in paying to transport produce and ship mostly air.
• Temperature requirements – keeping the meat at the correct temperature to keep it fresh while it is being transported is vital.
• Distance travelled/time taken (shelf life) – will the produce still be in date/ fresh to eat by the time it reaches the supermarket or place of sale?