Food carbon rating system could help reduce our diet’s environmental impact – Science News
Calculating the environmental impact of each item of food we eat is easier said than done.
A chicken on the table at Christmas in South Australia will have a smaller carbon footprint than its counterpart raised in Queensland — mostly because they’re fed different feedstock.
And while some people choose to make broad changes like opting for a vegetarian or vegan diet, there are still big variations between the environmental effects of different vegetables and vegetarian food products.
Fertilisers used in farming, the distance to market, packaging, feedstocks and farming methods are all part of the complex web that determines the environmental footprint of our food.
But shoppers can’t be expected to investigate every item in their trolley before they get to the checkout.
So what if the carbon footprint of our food was clearly labelled, similar to, say, the energy star rating we have on our appliances? Would that encourage consumers to eat a lower emissions diet?
Findings of a study published today in Nature Climate Change suggest it would.
University of Technology Sydney consumer psychologist Adrian Camilleri and colleagues at Duke University in the US asked more than 500 participants to estimate the emissions use, or “energy budget”, of growing or manufacturing different foods.
As a point of reference, they were also asked to guess the energy used in an hour by different household appliances.
Almost universally, the participants greatly underestimated food’s energy budget — especially that of red meat.
“The true carbon footprint ratio between the beef and the vegetable soup was about 10. Beef was about 10 times as bad, [but] without a [carbon] label, people thought beef was about twice as bad.”
What would carbon labelling look like?
Emissions from agriculture account for around 19 per cent of Australia’s total greenhouse gas budget.
But while our appliances typically come with energy ratings and we get electricity bills, the lack of any emissions indicators on food means consumers are less conscious of the issue, according to Dr Camilleri.
“There are a lot of sources of greenhouse gas emissions that people don’t think about — for example fertiliser, which goes into the feed for the animal,” he said.
The researchers gave 120 participants a choice of six soups to purchase — three meat and three vegetable — and each person was allowed to buy three cans each.
Half the group’s soups were labelled with carbon emissions ratings, and the other half without.
Those with the labelling purchased around a third less of the high emissions beef soup.
Additionally, those with emissions labelling on their foods more accurately estimated the relative impact of beef versus vegetables.
Although the research suggests that emissions labelling could help consumers reduce their environmental impact, some issues need to be taken into consideration, according to Michael Polonsky from Deakin University.
He warned that we are already struggling with information overload.
“You have fair trade, fair wages, you have not tested on animals, GM … there’s a new label on sunscreen lotions that says ‘reef friendly’,” Professor Polonsky said.
For the system to work, it would need to be a value that is easy for people to relate to and that we can put in context.
“As an individual piece of information, I think it’s valuable,” he said.
“But … is it going to be information that has real meaning and that people understand, or are we just giving them another number that doesn’t mean anything?”