How sustainable is our food system?
What if I offered you a $1 for every $10 that you gave me? You’d tell me that I was dreaming, crazy, or worse! But this is what we do with our food system. Currently (actually based on some relatively old studies – it has certainly deteriorated further) for every 1 unit of energy we consume in our food it takes at least 10 units of fossil fuel energy to produce it. Far from sustainable! And the trend is definitely in the wrong direction – as we increase our use of agricultural chemicals, artificial fertilisers and increased irrigation in particular.
However it is not what happens on the farm that is the largest energy culprit. Based on US studies (and I have no doubt that Australia is similar) only around 25% of the energy consumed in the food system can be directly attributed to farming activities. The remainder is split approximately evenly between distribution & processing, and at home storage (refrigeration / freezer) & preparation – including cooking.
Distribution is clearly a key element and requires around 15% of the total energy required. A quick look around the supermarket will show you why – canned tomatoes from Italy, fresh strawberries from California, dates from Turkey, Coffee from Columbia – the list goes on. In the US food on average travels more than 2400 kms from source to consumer.
Eating foods higher on the food chain is also a very inefficient use of energy – particularly for foods that can be directly consumed by humans. Animals are generally very inefficient at converting energy from grain into meat for human consumption. Typically it will take more than 10 units of energy from grain to produce 1 unit of energy from an animal. Clearly most of the energy that goes into an animal is used to keep it alive rather than for adding meat.
For a system to be truly sustainable it must ultimately require less external (ie excluding photosynthetic energy from the sun) energy to produce than what is consumed. So what can we do as individual consumers:-
Firstly eat lower on the food chain – less meat, more grains and vegetables. And clearly grass fed animals are not only going to be healthier for you, they have only around one third of the embedded energy
Secondly eat less processed foods. Fruit, vegetables and unprocessed grains all have much lower energy inputs
Thirdly, eat locally. This significantly reduces the “food miles” and also has a host of other benefits for community and localisation
Not only will this approach significantly reduce the embodied energy of your food it will also be a lot healthier!