Is consumer food waste giving the industry an unfair rap over emissions?

It’s by now a familiar statistic that around one-third of all food produced is lost or wasted each year. So much so that if food waste were a country, it would, due to the release of harmful greenhouse gases into the atmosphere as it breaks down in landfill sites, be the third biggest emitter, behind the US and China.

It’s also often reported that the global food system emits a quarter to a third of global greenhouse gasses. Now here’s a new number: around half of those emissions from food systems come from food loss and waste. What’s more, well over a third of emissions from food wastage is from food discarded by consumers.  

Why is this important? It suggests simple steps from people to prevent food loss and waste in their homes would go a significant way to reduce the much-maligned negative impact that the food system has on the environment.

A study recently published in Nature Food​ looked at 54 food commodities and 164 countries and regions. It estimated that global emissions from food wastage in 2017 totalled 9.3 billion tonnes of CO2 equivalent – more than double that of previous estimates. 

Food wastage is made up of both food loss (which occurs during the production, storage, processing, and transport stages) and food waste (that thrown away by consumers, retailers or food service providers).

That said, food discarded by consumers consisted of around 35.5% of the total food wastage emissions, the study said. These emissions were higher than the food thrown away by wholesalers, retailers and traders, which made up around 11% of the total, with the rest coming from other stages of food production.

First world problem ​

Consumer food waste is a bigger problem in the US and China. A third of the emissions caused by food waste from consumers in China and the US is comparable to the GHG emissions generated from the whole processing and transport stages globally, according to the study. Four non-European countries, meanwhile – Brazil, China, India and the US – are responsible for around 40% of all food wastage emissions, the research added.

But Europe’s consumers are not blameless and consumer food waste is very much a problem for the high-income Western world as whole. Almost half of UK parents, for example, admit to throwing away food which is still edible or able to be eaten safely, recent research from cream cracker maker Jacobs recently found. The main reasons: packets being opened for too long; too much food bought when shopping; people not knowing what to do with their leftover food. Almost half of respondents said they regularly bin leftovers from previous meals. Over a third struggle to eat all the fresh fruit and vegetables they buy.

Other research has warned the problem of food wastage will only get worse, as emerging countries like China and India continue to adopt Western nutrition lifestyles.

The authors of the Nature Food​ study noted that food loss (linked to the production, storage, processing, and transport stages) emissions are lower in countries with a higher per capita gross domestic product due to the availability of advanced and environment-friendly technologies for waste treatment. High-income countries should focus on reducing food waste and promoting plant-based diets (more on this point later), they said. By contrast, low-income countries could prioritise avoiding food loss from production and implementing proper waste treatment using appropriate technologies.

So can we estimate how much less global food system emissions would be if consumer-caused food waste was cut significantly? Indeed, Ke Yin, researcher at Nanjing Forestry University and one of the study’s authors, told FoodNavigator. “It would be a lot less”.​

To reduce food loss and waste at the consumer stage, the study’s authors wrote that “advocating rational food consumption behaviours and advancing technologies may both be helpful”.​ What exactly do they mean by ‘rational’? “In our opinion, ‘rational’ means that when people consume food they are aware of the environmental cost of the food products from production to the shelf and the environmental problems caused by food loss and waste, and weighing their own situation including the amount of food they eat, budget, and consumption time limitation,” ​Yin told us. “We urge people not to hoard and over-consume food.”​

The easiest battle to win?

Yin and his researchers recommend intervention strategies that include halving meat consumption, and deploying technological advances to reduce emissions, such as composting and anaerobic digestion. These interventions could half food wastage and cut around one-quarter of the greenhouse gas emissions from the global food system.

There’s no simple solution, however. For instance, cutting meat consumption reduces supply chain-related emissions (animal-source foods generate much higher greenhouse gas emissions than plant-based foods during production and logistics, the study said) but inherently increases the consumption, loss, and waste of plants and crops. “With the current waste management practice, most plant and crop wastes go to landfills or dumpsites, which generate even more emissions than landfilling meat waste,”​ Fei Xunchang, a researcher at the School of Civil and Environmental Engineering in Singapore and study co-author, also told us.

Tackling in-home food waste from consumers is surely an easier win. The food industry meanwhile is an easy target for popular climate fury. Farmers regularly complain, for example, they are being blamed unfairly for creating a large source of the climate emissions. But where’s the outrage on food waste?

There are further implications. Last year it was mooted that supermarkets and restaurants in Spain could face fines of up to €60,000 for wasting food. Why not fines for consumers too? 

“Our study contributes to better understand the full picture of the food waste problem, which is the very first step to solve this problem,”​ added Fei. “We do not have a perfect solution yet. Everyone should think about it.”     ​

References​

Cradle-to-grave emissions from food loss and waste represent half of total greenhouse gas emissions from food systems

Nature Food​

https://doi.org/10.1038/s43016-023-00710-3

Food Surplus and Its Climate Burdens

The Potsdam Institute for Climate Impact Research​

10.1021/acs.est.5b05088