The amount of food waste has reached a level that can no longer be ignored.
The Food and Agriculture Organization of United Nations (FAO) estimates that each year, one-third of all food produced in the world for human consumption never reaches the consumer’s plate.
Food waste has a huge impact on different areas of our everyday life, from social-ethical aspects, such as its contribution to increasing food poverty, to economic ones, such as the money we waste on food that is thrown out.
In this guide, we will focus on the negative impacts that food waste has on the environment, including increased greenhouse gas emissions, depletion of natural resources and biodiversity loss.
What is food waste?
Food waste is defined as the avoidable loss of any food originally meant for human consumption that is discarded rather than consumed. This includes food that has been left to spoil or expire, and food that is discarded prematurely. More technically speaking, it refers only to the loss of the edible parts of food (therefore it excludes food products such as bones, eggshells and coffee grounds), which is estimated to be around 1.3 billion tonnes.
It is important to note the difference between food waste, as defined above, and food loss. The Swedish Institute for Food and Biotechnology (SIK) underlines that food waste occurs mostly “at the end of the food chain (distribution, sale and final consumption)” and is due to behavioral factors. However, food loss is defined as the unavoidable loss that occurs during a food product’s life cycle. This can be due to logistical limitations, such as poor storage abilities during transportation, or natural events, such as severe weather causing crop failure.
This guide focuses on food waste because, unlike food loss, it’s a process that we as consumers have control over, however food loss also has negative social, economic and environmental impacts.
What are the causes of food waste and food loss?
Barilla Center for Food & Nutrition (BCFN)’s guide Food Waste: Causes, Impact, Proposals, differentiates the causes of both food loss and waste according to the various stages of the food supply chain, and in relation to the life standard of a country.
In developing countries, the most significant food losses are concentrated at the first stage of the food supply chain. This may be due to limitations in the cultivation, harvesting, and preserving techniques, or to a lack of adequate transportation and storage infrastructure.
In more developed countries, the largest proportion of food waste instead occurs at the final stages of the food supply chain, during consumption, which can happen at home, and at restaurants and food service establishments. However, even in these countries, there is also remarkable waste at the agricultural stage because of sizing and aesthetic standards, strict product quality regulations, production surpluses, or other marketing and economic factors.
Contribution to greenhouse gas emissions and waste of natural resources
By greenhouse gas emissions, we mean the levels of carbon dioxide and other gaseous byproducts that a company’s industrial processes produces in its business operations. Greenhouse gases (GHGs) are naturally occurring gases that absorb and emit radiant energy; without them, the average temperature of Earth's surface would be about −18 °C (0 °F), rather than the present average of 15 °C (59 °F). However, since the beginning of the Industrial Revolution humans’ activities have produced a 45% increase in the atmospheric concentration of carbon dioxide, vastly altering existing natural processes like carbon cycle.
Food waste is responsible for 6% of global greenhouse gas emissions. World Resources Institute's Climate Data Explorer, observes that if food waste were a country, it would be the third largest emitting country in the world, after the U.S.A. and China.
"If food waste were a country, it would be the third largest emitting country in the world"
But how exactly is food waste linked to GHG emissions?
Well, when producing food, we need land, energy, water, and fertiliser inputs, that all come at environmental costs. Considering that meat and milk production amounts to 78% of total global agricultural production areas, but only 11% of it becomes food available for humans, the unnecessary energy and overexploited resources to produce that outcome are enormous. The imbalance is even higher if animal products are wasted rather than consumed. We basically use energy and natural supplies to produce something that will only partly be consumed.
As mentioned previously, usually the highest carbon footprint of waste occurs at the consumption stage – the last stage of the food supply chain. This is a major issue because the further along the chain that food travels, the higher carbon intensity it will have accumulated. For example, a single tomato spoiled at the harvesting stage will have a lower carbon footprint than tomato sauce wasted at the retail stage, since the harvesting, transportation and processing accumulates additional greenhouse gases along the supply chain. For this reason, the percentage of food wastage and the percentage of carbon footprint emitted do not always match. Cereals, for example, do not contribute much on food loss, but still have, after meat carbon footprint, the highest level of carbon footprint emission of total food waste.
Biodiversity is defined as the number, variety, and variability of any living organisms. High levels of biodiversity are necessary for all ecosystems to thrive and are deeply linked to human well-being.
By altering the regular functioning of nature and artificially creating more land for production (for example through deforestation, monocultures, or the drainage of wetlands), humans put biodiversity under severe pressure which makes it unable to provide its natural “services”, such as clean air and water supply, insect pollination or protection against natural events. These changes contribute to climate change, natural resource overexploitation, the spread of exotic invasive species, and pollution. According to the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), the growing demand of meat and the animal feed that the industry requires greatly contributes to land overexploitation.
The dominant model of conventional agriculture also uses excessive amounts of pesticides and fertilisers, which modifies the water’s composition and pollutes it. In many places, the intensive use of water lowers the groundwater level, also negatively affecting biodiversity.
"The scale of modern food waste has reached the most alarming peak in history"
An article from Yale School of Environment, highlights how food waste has also impacted wildlife, causing a severe change in the natural animal chain and contributing to the decline of various species, including some that are already threatened or endangered. The article explains how the huge amount of food waste in garbage and discards has altered the predator-prey relation of some animals, causing the overcrowding of one species and the consequent declination of their prey. Even though animals have always been picking food scraps, the scale of modern food waste has reached the most alarming peak in history.
What can you do?
Self-educating is always the answer. There are plenty of organisations, sites, guides, articles, visual products, and experts talking about the subject – just choose the type of media you find most comfortable to learn with.
Healthline lists several ways to reduce household food waste. Among these we mention:
Smart shopping: calculate accurately what you need in order not to let the food expire
Correct food storage to make food last longer
Freezing food: use the freezer more frequently to avoid expiration
Creative cooking: save leftovers, skins, seeds, fruit water and so on to make other meals or drinks
In addition to this, inform yourself if your town has a community kitchen or fridge, where you can bring food that you know you won’t consume, that has a short expiration date, or you simply want to donate. These fridges or kitchens will provide free food for people who may be struggling financially.
Finally, you can check out the following resources to learn more about food waste and the effect it has on our ecosystems:
Food Exposed With Nelufar Hedayat (TV series; 2018-)
Wastecooking: make food, not waste (82 min; 2015)
Rotten (TV series; 2018-)
Wasted! The Story of Food Waste (TV series; 2017-)
Just Eat It: a Food Waste Story (75 min; 2014)
American Wasteland by Jonathan Bloom: www.wastedfood.com
Barilla Center Food & Nutrition: https://www.barillacfn.com/en
Food and Agricultural Organization of United Nations: http://www.fao.org/home/en
Grow Sheffield’s Abundance Project: www.growsheffield.com
Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services: https://www.ipbes.net
Stop Wasting Food movement: www.stopspildafmad.dk/inenglish.html
For more guides and resources on this topic, head to our dedicated Climate Crisis section