Module 5 - Food Food Footprints

? Our greenhouse gas emissions This graph shows us how much greenhouse gases various activities release. So if we want to really reduce our emissions significantly, then we need to concentrate on the things which release most greenhouse gases.

? Graph of UK food greenhouse gas emissions

? Nitrogen based fertilisers Artificial fertilisers containing nitrogen are added to crops and grazing land to make them more productive. They are made from natural gas, so greenhouse gases are emitted when they are being made. Not all the nitrogen is taken up by the plants, and is released into the atmosphere as nitrous oxide (N 2 O). Nitrous oxide is a greenhouse gas 296 more powerful than CO 2.

? Cows About half of our food related greenhouse gas emissions come from meat and dairy products. This is mainly because animals need to eat a lot to produce a relatively small amount of meat and dairy. Grazing land is often heavily fertilised producing nitrous oxide emissions.

? Milk Many modern cows don’t eat only grass. Because our global demand for meat and dairy products is much bigger than it used to be there simply isn’t enough grazing land to feed all our cows. Many of them are fed extra processed food. A lot of this food is made from soya beans. Many of the soya beans grown to feed our European dairy cattle come from vast plantations in what used to be the Amazonian rainforest, which has been cut down to grow them.

? Deforestation The rainforest is also destroyed to make way for cattle ranches because our global demand for beef has increased so much. Often the timber is not even used, because it is too difficult and expensive to take out of the rainforest, so it is burned on site releasing huge quantities of C0 2 into the atmosphere. Image credit: Leo F Freitas

? Belching cows and sheep! Of course, ruminant animals like cows and sheep are also responsible for another greenhouse gas! They fart and belch out methane which is about 23 times stronger than CO 2.

? Packaging All packaging is made from something using a certain amount of energy. Even recycled packaging has been made in a factory using energy to operate the machinery! Plastic is made from oil which takes a lot of processing. Metal needs to be quarried and processed. Even biodegradable packaging takes up land to grow the plants and energy to make it.

? Manufactured food Food made in a factory usually uses more energy than food made from fresh ingredients at home. A lot of processed food needs to be kept refrigerated or frozen. This uses a lot of energy!

? Food miles Transport accounts for a smaller percentage of emissions than most people think. But it is still important! Any food that comes by aeroplane will have the most impact. Air freight uses about 50 times more energy than ship freight! Ships are a fairly efficient form of transport, even though they do travel all around the world. Lorries that cover the same distance as ships use more energy. It is air freight and the final car trip to the supermarket that produce the greatest transport emissions!

? Landfill Any food that ends up in landfill sites will be squashed by the weight of all the other rubbish. When it is squashed, all the air is squeezed out, so it will rot without oxygen. This causes methane to be produced – a greenhouse gas 23 times stronger than C0 2 ! In Britain we throw away about a third of our food. So a third of the energy used to grow, process, transport and store the food is wasted too.