Let me begin with a question – do you know how many calories of fossil fuel it takes to produce one calorie of food? Incredibly, the answer to this is 10 fossil fuel calories produce only 1 calorie of food using current agricultural methods. I was astonished when I read this, as I hadn’t connected the growing of food with the use of non-renewable fossil fuels such as oil. When you see a field of wheat or potatoes, or cattle grazing on grass, it doesn’t immediately become apparent that their existence is so dependent on a resource that can’t be replenished. Here’s another fact that amazed me – agriculture is one of the largest consumers of fossil fuels out of all the industries in the UK, and one of the largest producers of greenhouse gases too.
Modern large farms are often described as totally addicted to fossil fuels. They use up large amounts of diesel fuel to power the massive machines that transport and process the crops and animals, but something that I hadn’t realised is that pesticides and fertilisers are also fossil-fuel based. The use of fossil fuels causes methane and other greenhouse gases to be released into the atmosphere, which are contributing to global warming. Modern farming methods rely on fertilisers and pesticides to grow crops at high densities in soil that would otherwise be unproductive. They use huge amounts of water as well, but that’s a subject I will come back to another time.
In prehistoric times, when humans first settled down to farm their food instead of roaming the planet as hunter-gatherers, their farming methods were sustainable. There were fewer people around to begin with, so they needed the soil to produce fewer crops. They farmed on a smaller scale, each family group simply producing enough for their own needs. Natural fertilisers such as food and animal waste were sufficient to keep the soil productive. Contrast that with modern life and you can see why high-intensity farming is now needed in order to feed the ever-growing population, and you can understand why farmers use the vast array of chemicals that they do.
High cost of meat production
Here are some more sobering facts: In the UK, 70% of fossil-fuel based fertiliser is used to grow cereals such as wheat, barley and oats. Around one third of all the cereal crop is grown not to feed humans, but for animal feed. Producing meat is an inefficient process – it takes between 10 and 16 kilos of grain to produce one kilo of beef. Not only is beef expensive to produce in terms of food, but cattle produce large quantities of methane as part of the digestion process (as do sheep and other animals), which again can only add to the climate change problem.
There are a number of projects ongoing to help farms to be less fossil fuel dependent, but widespread change is going to be a slow process. The next time you tuck into a juicy steak or some roast lamb, just think of the impact those few mouthfuls have already had on the environment and make the most of them.