Composting is a simple and effective way to live a greener lifestyle, and for those with a garden it’s also a great way to produce top quality plant food at absolutely no cost! The internet is full of useful resources that explain the key points of effective composting (links to some great sources are provided later on), but for many people the specific benefits of composting, and the extent to which it really makes a difference, remain a mystery. This brief overview will explain what compost is and how it benefits ourselves and the planet.
What is compost?
Compost is just organic material going through the natural process of decomposition: that is, being turned into soil by worms and microbes. By putting the organic material (i.e. food scraps and garden waste) in a compost bin we create a favourable environment for worms and microbes. As a result, they grow in number, and the process accelerates. This process is identical to what happens in worm farms.
The key difference between worm farms and compost bins is that worm farms are closed at the bottom, so some soil and worms must be added initially to get the process started, and they need to be monitored a little more closely. A major advantage, however, is that the liquid run off, which is extremely nutrient rich, can be captured and used as fertiliser. Worm farms are a great option for people who live in apartments, or only have small gardens.
There is no doubt that composting produces the best garden fertiliser, but for many of us, particularly city dwellers, that’s not necessarily a major consideration. The next section will explain how composting can hugely reduce both the amount of waste we send to landfill and the contribution of our kitchen scraps to climate change.
The benefits of home composting
There are great benefits from having a compost bin or worm farm. The first thing you will notice is a huge reduction in the amount of waste that ends up in the kitchen bin, and this has a bigger impact than you may realise. According to the World Bank, cities globally generated roughly 2.01 billion tonnes of solid waste in 2016, and up to 44% of this was food and organic material1! Although not all of this came from households, it is clear that composting can greatly reduce the amount of waste that goes to landfill.
Diverting food waste from landfill is also the main way that composting reduces the direct impact of our household bin on the climate. The breakdown of organic material releases both carbon-dioxide and methane, but the ratio in which these gases are produced depends on the environment in which decomposition occurs. This is critical, because methane is roughly 26 times more potent as a greenhouse gas than carbon-dioxide2.
Food waste that goes to landfill breaks down anaerobically (without oxygen), and as a result releases a relatively high ratio of methane to carbon-dioxide3. A well-managed home compost pile, on the other hand, can largely avoid not only the methane emissions associated with the decomposition of food waste, but also the fossil fuel emissions required to transport it to landfill4. This means composting is a great way to reduce some of the negative environmental impact of our kitchens.
For those that do intend to use their compost on the garden, there are further benefits. First of all, good compost is an excellent fertiliser. More importantly though, it not only alleviates greenhouse gas emissions associated with producing and transporting artificial fertilisers, but it also prevents chemicals from being washed into the waterways and oceans5.
So even if you don’t grow your own food, or aren’t a particularly avid gardener, composting reduces the amount of waste that goes to landfill and its associated greenhouse gas emissions. Beyond this, composting also restores elements to the natural cycle, which is a positive outcome in itself!
How to do it
Oxford City Council supports composting, and you can put your food waste into your brown bin. There are also discounts available through the council on compost bins for those keen to try at home!
There are some important points to note regarding what to include, and balancing food scraps with garden scraps, but the key is to not overthink it. This easy to follow three-minute video from Gardening Australia’s Costa Georgiadis has literally all the information you need to get started, and features Costa’s magnificent beard:
For those who want to know more about the specifics of composting, Gardening Australia provides a useful fact sheet:
At the end of the day, remember that what you put in to compost was going into the bin anyway, and if it doesn’t work perfectly straight away you can always address issues as you go. Good luck!
1. Kaza, S., Yao, L., Bhada-Tata, P. & Van Woerden, F. What A Waste 2.0: A Global Snapshot of Solid Waste Management to 2050. (2018).
2. Lelieveld, J., Crutzen, P. J. & Brühl, C. Climate effects of atmospheric methane. Chemosphere 26, 739–768 (1993).
3. Dorward, L. J. Where are the best opportunities for reducing greenhouse gas emissions in the food system (including the food chain)? A comment. Food Policy 37, 463–466 (2012).
4. Boldrin, A., Andersen, J. K., Møller, J., Christensen, T. H. & Favoino, E. Composting and compost utilization: Accounting of greenhouse gases and global warming contributions. Waste Manag. Res. 27, 800–812 (2009).
5. Morton, T. G., Gold, A. J. & Sullivan, W. M. Influence of Overwatering and Fertilization on Nitrogen Losses from Home Lawns. J. Environ. Qual. 17, 124–130 (1988).