Here’s a recap from our previous post: the environmental impacts of food waste can be classified into two parts – the direct pollution of air, water, and soil, as well as the exacerbation of negative environmental impacts of food production and consumption. This blog entry will zoom in on the environmental pollution which occurs as a direct consequence of food wastage.
Much of the environmental pollution caused directly by food wastage may be attributed to the improper handling and disposal of food waste, regardless of whether these acts are intentional. This allows contaminants to be released into the environment, where some primary pollutants may undergo chemical reactions to create secondary pollutants that further contribute to the consequences.
The decomposition of food waste results in high levels of methane emissions, which creates a greenhouse effect that is around 25 times stronger than carbon dioxide emissions (Canadian Broadcasting Corporation (CBC), 2009; Food and Agriculture Organisation of the United Nations (FAO), 2013, pp. 20-21). This is a persistent problem for countries where food waste is sent to landfills, as this form of waste disposal exposes the air above landfills to high concentrations of methane, as the remnants continue to decompose in broad daylight.
However, the aforementioned methane emissions are not exclusive to food waste generated from consumption. FAO (2013, p. 19) notes that approximately 70 percent of greenhouse gas (GHG) emissions of rice wastage in South and Southeast Asia come from rice production. As rice paddy fields are often flooded, methane is generated from the decomposition of organic matter found in these fields, which also makes rice a methane-emitting crop. This corroborates the research of Topp and Pattey (1997), which identifies soils as both sources and sinks for atmospheric methane emitted by paddies, landfills and wetlands.
Meanwhile, we need to remember that the ill effects of global warming caused by methane and other GHGs are not just restricted to the local environment, as air pollutants are transboundary in nature. Once emitted to the atmosphere, the GHG particles can travel long distances, and be deposited in water bodies and soil. On the other hand, poorly-designed waste disposal infrastructure may also result in soil and water pollution by food waste, stemming from gaps such as landfill leachate (from badly-maintained landfills) and improper disposal methods which lead to the pollution of waterways.
Overall, I feel that infrastructure, legislation, enforcement and shifts in consumer mindset are all crucial in helping the world cut down on food waste. One thing that surprised me after reading up on food waste was the sheer amount of food produced that doesn’t even go past the processing stages. Could that be due to the selective processes food producers undergo to identify what wholesalers and consumers prefer, based on their own assumptions of appeal? I suppose I can now understand why some people prefer to grow their own food (if they have the means to do so).
Hope everyone’s still doing well amidst the final weeks of the semester!
Have a good week,
Jialing
Reference List
Canadian Broadcasting Corporation (CBC) (2009) ‘Food waste has environmental impact: scientists’, CBC News, 24 November. Available at: https://www.cbc.ca/news/technology/food-waste-has-environmental-impact-scientists-1.828102 (Accessed: 31 October 2020).
Food and Agriculture Organisation of the United Nations (FAO) (2013) Toolkit – Reducing the Food Wastage Footprint. Available at: http://www.fao.org/3/i3342e/i3342e.pdf (Accessed: 31 October 2020).
Topp, E. and Pattey, E. (1997) ‘Soils as sources and sinks for atmospheric methane’, Canadian Journal of Soil Science, pp. 167-178. doi: 10.4141/S96-107.