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Waste Series Article 1


Globally, food is responsible for 30% of our greenhouse gas emissions. We know that meat (in particular beef) is a huge part of that, and all the other steps in production, like storage, transport, pesticides etc. have a part to play as well. But, what you probably don’t know is that of the total 50 billion tonnes of carbon dioxide (CO2) equivalents released into the atmosphere each year, 3.3 billion tonnes of that comes from food waste. Personally, I think this statistic is mind blowing. Not only did it take a load of greenhouse gases to make the food, wasting it then creates a whole bunch more! Let’s take some time to understand how food waste is responsible for almost 7% of the global greenhouse gas emissions and why food waste doesn’t make sense. If you want to learn about what you can do to reduce the problem, check out Article 2: Far Too Much Food – How You Can Help.


The Emissions

When I think about waste, it seems easy to understand how products like plastic being incinerated or sitting in landfill for hundreds of years can have a serious impact on the planet. But when thinking about food, sending it to landfill doesn’t sound as awful – it decomposes and disappears quite quickly, right? And surely that decomposition happening at a landfill is the same as it decomposing in a compost heap or in an anaerobic digester? Well, as you might have guessed, that’s not quite right.

When food rots at a landfill site it happens anaerobically, i.e., without oxygen. If you can imagine a landfill, the waste is all dumped on top of each other and just left. As soon as the food ends up in a pile, it can’t get enough oxygen to support aerobic bacteria (they need at least 5% oxygen to survive). So, decomposition happens using anaerobic bacteria which release vast quantities of methane. Methane, as a greenhouse gas, is 28 times more potent than CO2. And this anaerobic decomposition is the main reason food waste ends up being responsible for 3.3 billion tonnes of CO2 equivalents each year.

If you compost your food waste, something else happens. Composting isn’t that tricky in practice, but there is actually quite a lot of complicated stuff going on in the heap. There are three main types of microbes that digest the waste you add to your compost – bacteria, actinomycetes (kind of like fungi and mould) and fungi. They all break down different parts of the waste without producing copious amounts of methane and leave you with nutrient rich soil perfect for fertilising your garden. All you do is turn your compost regularly and leave out certain items. Why? Well as we discussed above, anaerobic decomposition produces harmful biproducts. Turning the compost means enough oxygen is available to support aerobic bacteria which don’t produce methane, but release nitrogen, phosphorus, and magnesium (all good for plants) instead. Being selective with what you add to your heap means you maintain your good microbe balance. If you were to add, for example, pet faeces you’d also add harmful bacteria which would produce toxic byproducts, while products coated in fungicide would destroy your compost’s microbe balance all together.

Anaerobic digestion is the process that disposes of what is collected in your local food waste scheme. As you can probably guess, this process involves the breaking down of organic material (food, manure, garden waste) by microbes (bacteria) in the absence of oxygen. You would be correct in thinking that that sounds a lot like the bad process happening when you send your food waste to landfill. The difference, however, is that anaerobic digestion happens in a reactor (basically a sealed tank) which stops the greenhouse gases from leaking out. Plus, the exact bacteria doing the digestion can be controlled, which affects the end products. The resulting gas is referred to as ‘biogas’ – a mixture of methane, carbon dioxide, water vapour and hydrogen sulphide. Biogas is then used to generate electricity, heating… pretty much any process that requires natural gas. It can also be purified into its different gas components and used for renewable energy – awesome, right?! And it doesn’t stop there, the other biproduct is digestate – everything solid and liquid left at the end of the digestion. The digestates can be separated into their natural states and used for a variety of things, including fertiliser and animal bedding. That’s right, anaerobic digestion means food can go full circle and become the thing that helped it grow in the first place. This can also be done on a smaller scale at home, leaving you with biogas to power your house and digestate to fertilise your garden!

The disposal of food waste, whether that be through decomposition, composting or digestion, will always result in biproducts. How it is disposed of, however, will affect whether those biproducts are potent or toxic, and whether they can have a second life as something useful. Hence why we shouldn’t send our food waste to landfill.


It Doesn’t Make Sense

Here are some pretty horrifying facts (in my opinion) that I think highlight why wasting food is completely nonsensical and silly.

Currently, we waste one third of the food we produce. Think about all the emissions and pollutants, all the time and money, all the water and energy that goes into producing our food… a third of that is for nothing. And on top of that, the third we waste is doing even more damage to our planet. Greenhouse gases are arguably the main driver of climate change and food as a whole is responsible for 30% of our annual global emissions. If we just didn’t waste food, there would be a third less being produced, potentially meaning a 10% reduction in our global annual emissions.

There are 800 million people on this planet that are suffering from hunger and malnourishment. All those people (yes, all 800 million of them) could be fed with less than a quarter of the food wasted by Europe and the US.
By 2050 another two billion people are expected to join the population. All of whom are going to need to be fed. We could do this by increasing food production by 60% (on a planet that is already being over farmed), or we could simply stop wasting so much food. If we have people on the planet that do not have enough food to survive, there shouldn’t be people throwing it away. Particularly when the amount of food wasted grossly outweighs the amount needed to feed those people.
We currently produce enough food to feed everyone and then some, yet some people have no food, and because of the amount we waste, people are worrying about the addition of more people and how we will be able to increase food production, when the real solution is (figuring out how) not to waste.

Food waste occurs at substantial levels regardless of income. The average American spends $1,300 a year on food that goes in the bin. Wasting food costs you money. If that food was not wasted, neither would that money. Personally, I have spent months trying to save up that sort of money to spend on something special and worthwhile. As it turns out, not wasting food is an easy way to save. And a happy side effect is that you end up doing your bit for the planet as well.


To learn about what you can do to reduce the problem, check out Article 2: Far Too Much Food – How You Can Help.

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