Study Suggests Food Swaps Could Reduce Greenhouse Gas Emissions from Groceries by a Quarter

A new study in Australia has shown that shoppers making simple food and drink switches could reduce greenhouse gas emissions from groceries by 26%.

Researchers from The George Institute for Global Health and Imperial College London’s School of Public Health conducted the most detailed analysis ever on the environmental impacts of a country’s food buying behaviour. They looked at comprehensive data on greenhouse gas emissions and sales for tens of thousands of Australian supermarket products, typical of the Western diet of many countries.

Their study, published today in Nature Food, also found that making bigger changes – like swapping a frozen meat lasagne for the vegetarian option – could reduce emissions by as much as 71%.

The researchers are calling for more on-pack labelling of greenhouse gas emissions for every packaged food product so that consumers can make informed choices.

Lead author and epidemiologist Dr Allison Gaines, who conducted the analysis for The George Institute and Imperial College London’s School of Public Health, said, “Dietary habits need to change significantly if we are to meet global emissions targets, particularly in high-income countries like Australia, the UK, and US. Consumers are willing to make more sustainable food choices, but lack reliable information to identify the more environmentally-friendly options.”

“Incorporating sustainability targets in national food policies could directly contribute towards reaching global environmental goals, without burdening consumers”Dr Pareskevi SeferidiSchool of Public Health, Imperial College London

The researchers calculated the projected emissions of annual grocery purchases from 7,000 Australian households using the George Institute’s FoodSwitch database and global environmental impact datasets. More than 22,000 products were assigned to major, minor and sub-categories of foods (e.g. ‘bread and bakery’, ‘bread’ and ‘white bread’, respectively) to quantify emissions saved by switching both within, and between, groups.

They found that making simple switches within the same sub-categories of foods could lead to emission reductions of 26% from groceries in Australia, while switches within minor categories of foods could lead to even bigger emission reductions of 71%.

“The results of our study show the potential to significantly reduce our environmental impact by switching like-for-like products,” said Dr Gaines.

It is estimated that around one-third of global greenhouse gas emissions are attributable to the food and agriculture sector, and the combined health and environmental costs of the global food system are around $10-14 trillion (£8-11 trillion) per year.

Research Fellow Dr Paraskevi Seferidi at the School of Public Health, who also worked on the study, says: “This shows that incorporating sustainability targets in national food policies could directly contribute towards reaching global environmental goals, without burdening consumers. This is why we are urgently calling for robust legislation that targets high-emission food products.”

Professor Bruce Neal, Executive Director at The George Institute Australia and Professor of Clinical Epidemiology at Imperial College London, believes that innovative ways of approaching the problem could enable consumers to make a real impact.

The George Institute has developed a free app based on this research called ecoSwitch, currently only available in Australia, which allows shoppers to use their phones to scan a product barcode and check its emissions.

Professor Neal said: “EcoSwitch is a much-needed first step, but our vision is for mandatory display of a single, standardised sustainability rating system, on all supermarket products.”