Food production contributes around 37 per cent of global greenhouse gas (GHG) emissions, showing the huge impact that our diets have on climate change. What’s more, animal-based foods produce roughly twice the emissions of plant-based ones.
“There are many studies that have already been published on this topic, but ours is the first one that quantifies the emissions explicitly from plant-based production and animal-based production on a global scale,” says Atul Jain at the University of Illinois.
Jain and his colleagues used data from more than 200 countries to estimate that food production makes up about 35 per cent of total GHG emissions, rising to 37 per cent when emissions from food-related disturbances, such as burning savannah to clear space for farming, are included.
They looked at the emissions of carbon dioxide, methane and nitrous oxide from the production of 171 different crops and 16 animal products in 2010, as the most recent available data was from 2007 to 2013. The researchers found that rice production had the highest plant-associated GHG emissions, while beef production contributed the most to animal-associated emissions.
According to their estimates, global food production contributes about 17.3 billion metric tonnes of carbon dioxide equivalent per year, almost 19 times the amount from the commercial aviation industry. Of these emissions, 57 per cent were related to the production of animal-based foods and plant-based food production accounted for 29 per cent. The remaining emissions came from agricultural land being converted from non-food crops like cotton to food production.
South and South-East Asia had the highest plant-food-related emissions overall, while South America had the highest animal-food-related emissions. “Some regions are showing much higher emissions. It’s not only because of the consumption side but also the production side,” says Jain. Changing the types of fertilisers used on land for plant-based food production could help reduce production emissions, he says.
Journal reference: Nature Food, DOI: 10.1038/s43016-021-00358-x
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