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  • Mirna Wabi-Sabi

Food Waste And Methane Emissions

Updated: Feb 21, 2023

Written by Mirna Wabi-Sabi and photographed by Fabio Teixeira.

Originally published at G&R.

Photos by Fabio Teixeira, from Plataforma9.

Recycling and single use plastics are often talked about in mainstream media in the context of environmental sustainability. Meanwhile, fossil fuels and the meat industry are brought up as sources of greenhouse gas emissions. Food waste seems to have taken a backseat in both of these discussions, and when it’s brought up, it’s more so within the framework of morality than measurable environmental damage. Kids are told to finish their dinners because “there are children starving in Africa”, or that food shouldn’t be wasted because of the environmental cost of producing and transporting food to the table. The carbon footprint of food waste is associated with other, related, unsustainable industries such as packaging, transport and factory farming — but not only.

The difference between food waste and loss is that loss happens before the food arrives at the consumer’s table; in farms, storage and transporting. Waste, on the other hand, is in our garbage bags. But unfortunately, there isn’t yet a robust incentive to collect data on it. According to the 2021 UN Food Waste Index report:

“An estimated 8-10 per cent of global greenhouse gas emissions are associated with food that is not consumed (Mbow et al., 2019, p. 200) – and yet none of the Nationally Determined Contributions to the Paris Agreement mention food waste (and only 11 mention food loss) (Schulte et al., 2020).” (UNEP, 2021, Page 20.)

Food waste is as significant to the discussion of sustainability as food loss — more significant if we consider that mitigating its damage is within the reach of anyone in an average household. Food decomposing in landfills releases methane into the atmosphere, amounting to 4.4 billion tonnes of carbon dioxide (GtCO2 eq) annually (UNEP, 2021). This means over 4 times the global emissions from flights in 2018 (1.04 GtCO2, Our World in Data, 2020), 87% of “global road transport emissions” (FAO, 2015), or “32.6 million cars’ worth of greenhouse gas emissions” in the U.S. alone (WWF).

Of all stages of food production which contribute to greenhouse gas emissions, household consumption has the highest carbon footprint. When added, waste from production and storage emit about the same amount of greenhouse gases as from consumption alone. And not all foods contribute equally to this footprint. While meat, for instance, amounts to less than 5% of total food wastage, it contributes to over 20% of the footprint. Starchy roots, on the other hand, have the reverse effect, where they represent almost 20% of the total wastage, but only 5% of the footprint (FAO, 2015).

It will come as no surprise that high income regions of the world waste more food than lower income regions, even if data isn’t systematically collected in some countries. In European countries and in the United States, grocery shops have been known to pour bleach over expired commodities, leading France to be the first nation to ban the practice in 2015, unanimously passing a law aimed at cutting down on food waste (Time, 2015). Nevertheless, the Food and Agriculture Organization of the UN reasonably assumed a “larger progress margin” for “developing” countries on what can be achieved in food waste mitigation by 2030 (FAO, 2015).

By Fabio Teixeira

Few behavior changes necessary for handling climate change overlap the issue of poverty and carbon footprint so blatantly. A shift in how food is consumed can combat food insecurity and reduce greenhouse gas emissions at the same time. It should be unimaginable to choose food waste over distributing food for free and sharing basic-need resources. If not at the corporate food industry level, at the very least we can do something in the realms of our own kitchens, those of us who have kitchens. What can we do to ensure no food ends up in our garbage bags? Some of the most intuitive suggestions are: avoid over-buying, avoid over-cooking, store properly, freeze, consciously prioritize your meals based on what will expire first, share meals with other families/your community, and compost.

Discarding food waste in the drain is not a solution, because it not only can negatively affect wildlife, organic material left over from water treatment will end up in landfills anyway (Cary Institute, 2016). Composting is the best solution for disposing of non-edible foods because methane is produced “by microbes in the absence of oxygen”, and the composting process is aerobic, meaning, involving/requiring oxygen (Government of Western Australia, 2021). Many believe that composting is not possible in an urban setting, but that isn’t the case. When executed properly, the process can be done in small places with minimal odor (that is when a community initiative isn’t realistic). It may even be done with cardboard, which can considerably reduce the amount of waste produced in a household by disposing of both organic waste and paper recycling at the same time (Conserve Energy Future).

To live with and handle one’s own waste goes a long way to incentivize members of a household to produce less waste in the first place. And we wouldn’t be painting a clear picture of the issue of food waste management if we didn’t acknowledge the intersectional nature of how many households operate. Gender roles are still a factor in most families, and domestic chores disproportionately fall on women, as well as domestic workers being mostly women (ILO).

A recent U.K. study reveals that the pandemic has exacerbated the gender inequality of domestic chores, as women maintained their social-isolation level of “involvement in housework and childcare” after they went back to work, while fathers did not (Demographic Research, 2022). In this sense, any solution to minimizing food waste should involve the interest, understanding and actions of all household individuals past their pre-school years.

“Solving problems, being creative and getting results for … efforts” are things people as young as grade-schoolers should be experiencing (Healthy Children), especially when it involves such an indispensable and habitual human practice — eating.

“Several studies highlight that if current dietary trends are maintained, this could lead to a significant climate-change emissions from agriculture of approximately 20 GtCO2-eq per year by 2050.” (FOA, 2020)

Clearly, there is a problem to be solved, minimal levels of creativity are required for the solution, and our efforts can not only have measurable results, but can also improve the health of our families, our communities and our planet.

By Fabio Teixeira


Carbon footprint: The total amount of greenhouse gases emitted by an action (Nature Conservancy).

CO2: Carbon dioxide.

CO2e: All greenhouse gases.

Food Loss: Occurs in the production stage of the food industry; at farms, in processing and transport.

Food Waste: Occurs after food arrives at the consumer when it is discarded.

Greenhouse gases: Carbon dioxide (CO2); Methane (CH4); Nitrous oxide (N2O); Industrial gases — Hydrofluorocarbons (HFCs) Perfluorocarbons (PFCs) Sulfur hexafluoride (SF6) Nitrogen trifluoride (NF3). (EIA, 2021)

GtCO2: One billion tonnes of carbon dioxide. (Law insider) GWP 1 (Ecometrica).

GtCO2eq: Carbon dioxide equivalent (CO2eq) stands for a unit based on the global warming potential (GWP) of different greenhouse gases (Climate Policy Info Hub).

GWP: Global warming potential.

Methane: “1kg of methane causes 25 times more warming over a 100 year period compared to 1kg of CO2, and so methane [h]as a GWP of 25.” (Ecometrics). “Methane is emitted during the production and transport of coal, natural gas, and oil. Methane emissions also result from livestock and other agricultural practices, land use and by the decay of organic waste in municipal solid waste landfills [emphasis added].” (EPA, 2022)


Cary Institute (2016) “Stop putting food waste down the drain” <>.

Climate Policy Info Hub <>.

Conserve Energy Future. “Is Cardboard Compostable?” <>.

Demographic Research (2022) “Gender inequality in domestic chores over ten months of the UK COVID-19 pandemic: Heterogeneous adjustments to partners’ changes in working hours” <>.

Ecometrica <>.

EIA, U.S. Energy Information Administration (2021) <>.

EPA, U.S. Environmental Protection Agency (2022) <>.

FAO, Food and Agriculture Organization of the United Nations (2020) <>.

FAO, Food and Agriculture Organization of the United Nations (2015) <>.

Government of Western Australia, Department of Primary Industries and Regional Development (2021) <>.

Healthy Children <>.

ILO, International Labour Organization <>.

Law Insider <>.

Nature Conservancy <>.

Our World in Data (2020) <>.

Time (2015) “French Parliament Unanimously Approves Law to Cut Food Waste” <>.

UNEP, United Nations Environment Programme (2021) Food Waste Index report <>.

WWF <>.


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