Food waste carbon footprint

Enough food is produced to feed 1.5 times the whole human population. (Holt-Giménez et al., 2012). Yet, 690 million people – 8.9 % of the population – still suffer from hunger (UN, 2021). Besides the considerable issue of inequality and the goal 2 “Zero Hunger” of the UN, this problem raises the question of that excess of food which ends in waste, of the greenhouse gas (GHG) emissions, and of all the resources and energies mobilised to end in the bin.

Food wastage occurs at every stage, from the fields to the plate, and in the factories too. Yet, this article here focusses on food waste at home in developed countries, from the groceries to the bin. It will differentiate the terms food waste, loss and wastage and present the key figures and consequences of food waste. Then, it will develop solutions that everyone can put in practice in his day-to-day life to reduce or, at least, upgrade the waste.

First, it is important to distinguish food loss, food waste and food wastage. Indeed, food loss refers to the upstream deterioration of food than was originally intended for human consumption, while food waste stands for the food, good for human consumption, that is being discarded. Then, food wastage is the combination of both food loss and food waste. (FAO, Summary Report, 2013). Then, one may have in mind that food wastage has a carbon footprint between 3.3 and 4.4 GtCO2eq/year (depending on calculating method). (FAO, Summary Report, 2013), which represents about 8% of the global emissions. Indeed, about 1.3 Gt of in date food is thrown away each year in the world, for which the food loss is more responsible than the food waste.

This wastage leads to unnecessary agricultural space, food production, manufacturing, packaging, retail, distribution and then landfill. Food waste is then a great source of GHG emissions, especially methane and nitrous oxide, for cattle breeding and artificial fertilisers, which are known to have far greater warming effects than CO2. Moreover, it is also a source of energy and money loss, as it represents almost USD 1 trillion each year. (IPCC, 2019). Consequently, food wastage cannot fit with the definition of sustainability, with none of the three pillars of society, finance, and environment. It is hence an issue that must be properly tackled by everyone, at every of its stages.

Nevertheless, as in many environmental issues, countries do not share the same responsibilities. Indeed, Europe, North America, Oceania, and Industrialised Asia have a high rate of available food that is wasted: 42% for North America and Oceania for example. Even more important is that, in those rich countries, the biggest cause of food wastage is the consumption, which belongs to food waste part, (between 46% and 61%) whereas, in less affluent societies, the loss is bigger upstream, in agricultural production, in the food loss part. (figure [1])(FAO, Summary Report, 2013).

This means, in affluent societies, there is a big issue in consumers’ behaviour. In a country like France, 20kg to 30kg of foodstuffs are wasted per year and per capita, of which 7kg still packaged, which reflects a lack of anticipation and prevention in the groceries planning. (ADEME, 2020). It is therefore important to notice that, even if consumption is not the greatest cause of food waste (20% of the total on average), it represents 35% of the carbon footprint, since the food products have higher carbon intensity at the end of the chain. Moreover, different types of foodstuffs are not equally wasted and do not represent the same carbon footprint. The clearest example is meat, which accounts for 4% in weight of the total wastage but represents 21% of carbon footprint of food waste, especially because of the methane emitted by cattle. (figure [2]) (FAO, Summary Report, 2013) (Baldwin, 2015).

Thus, to reduce food waste and emissions in that sector, consumers, especially in affluent countries, should perform a drastic change in their habits. Here follow quite a few ideas to achieve it, ordered by impact and importance.

When we approach the prevention of waste, a famous method is the 3 (or 5) R: (Refuse), Reduce, Reuse, Recycle, (Rot). The order is essential for the method to be efficient, and can be adapted to all type of waste, as we will explain it for food waste.

First, Refuse and Reduce can be blended in one first step called “Source Reduction”. As outlined earlier, about 30% of the food thrown away is still packaged. (ADEME, 2020). This is the result of two main causes: the lack of groceries planning and the misunderstanding of food labels. The latter causes lots of “early waste” of the food: as soon as the date is past, people tend to throw. This comes from a confusion between “use by” and “best before”. NHS explains that, while the former is about safety, the latter is about quality: most of the food thrown away could have been eaten without risks on health. (NHS, 2021). We should then think twice before discarding food only because the “best before” date has passed from one day. In addition to that, food stocks should be better planned not to buy too many products at a time, otherwise they will expire. Finally, if it appears that we have to much food and cannot eat it before the “use by” date, why not sharing it to association or people in need? Besides reducing food wastage, a good deed would be achieved.

Then, Reusing the food could also reduce the amount of waste. Indeed, Many people still throw away the leftovers instead of keeping them for another meal. As said before, the food could be given to people in need if more than needed has been prepared. But it could also be given as food for animals or re-cook leftovers in another meal. Thereon, more and more recipes are nowadays spread on internet and social medial about how to cook leftovers, peelings, or even zest in easy to do dishes.

As mentioned before, it is vital to follow the order of the method to be more efficient. As an example, if leftovers are eaten or given for animal feeding, it will be between 26 and 250 more eco-efficient than if they are put into anaerobic digestion. (FAO, Reducing the food wastage footprint, 2013). However, if they cannot be reused, it is better to recycle them than to do nothing.

The Repurpose/Recycling step, where the food has the status of waste, gathers all the ideas of using food not for feeding purpose. As for example, coffee ground can be used as a scrub for the skin, or as soil mulching while gardening, as for eggshells or nutshells. Besides upgrading the waste, it has benefits for the skin or for the mulching, which helps soil to keep its humidity and protect plants from brutal temperature variations.

Moreover, a developing sector is also the anaerobic digestion of food waste, which is the microbiologically decay of food waste “in enclosed containers in the near absence of oxygen”. It has the double benefit of digestate and producing biogas, that can be then used as energy source. (FAO, Reducing the food wastage footprint, 2013)

To finish with, if all the solutions above have been exhausted, we still can put our waste to compost (Rot step), so they do not end in landfills and can afterwards be reused as fertiliser in the garden.

Although they are not as efficient as the solutions before, anaerobic digestion and composting are still better than simply landfilling, as they give a value to the waste.

To put it in a nutshell, food waste raises huge issues of wastage, carbon emissions, resource exploitation and inequality. The 1.3 Gt of edible food wasted each year, representing 3.3 Gt CO2eq while almost 700 million people suffer from hunger do not conform with sustainable world. Nonetheless, we all can reduce it in our household with a change in our behaviour, with habits of prevention and reuse, or with some creativity to turn waste into a resource. Many other solutions that the ones presented here do exist too, and education is then vital to raise awareness about that problem and its solutions.

Future Thought Leaders is a democratic space presenting the thoughts and opinions of rising Energy & Sustainability writers, their opinions do not necessarily represent those of illuminem.

References

ADEME, 2020. Réduire le gaspillage alimentaire [Reducing food wastage] [online]. France : ADEME, Agence de la Transition Ecologique. (in French). [viewed 5 November 2021]. Available from: https://www.ademe.fr/expertises/dechets/passer-a-laction/eviter-production-dechets/dossier/reduire-gaspillage-alimentaire/enjeux​

BALDWIN, C.,2015. The 10 principles of food industry sustainability. [online] Hoboken, NJ: Wiley Blackwell. [viewed 5 November 2021]. Available from: https://discover.gcu.ac.uk/permalink/44GLCU_INST/1ulognu/alma991002491337403836.

FAO, 2013. Food wastage footprint; impacts on natural resources. Summary Report. [online]. Food and Agriculture Organisation (FAO), UN. [viewed 31 October 2021]. Available from: https://www.fao.org/docrep/018/i3347e/i3347e.pdf​

FAO, 2013. Reducing the food wastage footprint. [online] Food and Agriculture Organisation (FAO), UN. [viewed 31 October 2021]. Available from: https://www.fao.org/docrep/018/i3342e/i3342e.pdf​

FAO, 2015. Food wastage footprint & Climate Change. [online] Food and Agriculture Organisation (FAO), UN [viewed 4 November 2021] Available from: http://www.fao.org/3/a-bb144e.pdf​

HOLT-GIMÉNEZ, E., SHATTUCK, A., ALTIERI, M., HERREN, H. & GLIESSMAN, S., 2012. We Already Grow Enough Food for 10 billion People ... and Still Can't End Hunger. [online] Journal of Sustainable Agriculture. 36(6), pp.595-598. [viewed 1 November 2021]. Available from: http://www.tandfonline.com/doi/abs/10.1080/10440046.2012.695331​

IPCC, 2019. SRCCL Report, c. 5. [online] Intergovernmental Panel on Climate Change (IPCC). [viewed 4 November 2021]. Available from: https://www.ipcc.ch/site/assets/uploads/2019/08/2f.-Chapter-5_FINAL.pdf​

NHS, 2021. Food labelling terms. [online] National Health Service (NHS). [viewed 4 November 2021]. Available from: https://www.nhs.uk/live-well/eat-well/food-labelling-terms/​

United Nations, 2021. Sustainable Development Goals. Goal 2: Zero Hunger [Online] United Nations (UN). [viewed 31 October 2021]. Available from: https://www.un.org/sustainabledevelopment/hunger/​