For fresh fruit and vegetables, transport can add significantly to the emissions associated with food production.

Almost a third of global greenhouse gas emissions are connected to food production. Does where you buy your fruit and vegetables still matter?

ood miles – the distance between farm, factory and plate – gained prominence in the early 2000s. The idea was that longer, more complex supply chains caused higher emissions than food sourced closer to home. The simple solution? Buy locally grown and shop nearby.

The intervening decades have underlined other environmental concerns with the modern food system, from the emissions associated with animal agriculture to the problems of food and packaging waste.

Dr Kimberley Reis, who researches regional and local food resilience at Griffith University, says supply chains in Australia are largely shaped by the grocery sector. Food can travel vast distances across the country – and beyond – to reach supermarket outlets, with freight costs passed on to consumers.

But this year’s war in the Middle East has refocused attention on the role of transport and the importance of self-sufficiency, including the threat of rising food prices as a result of diesel price spikes. It raises the question: do food miles still matter?

Where food miles fit in Assoc Prof Mengyu Li at the University of Sydney says almost a third of global greenhouse gas emissions are connected to the food system through land clearing, raising animals, growing crops, processing and packaging, transport and waste.

“We cannot meet our climate goals if we don’t do anything about [the] food system,” she says. Overall, the largest contributions are connected to livestock and land clearing, but transport and waste are also significant, she says.

Transport – across the entire supply chain – makes up about 19% of food system emissions, a study co-authored by Li in Nature Food found.

The relative importance of transport emissions can vary for different types of food, depending on the distance travelled, mode of transport (truck, plane, ship, rail, car or foot) and whether refrigeration is required, she says.

For some products, such as beef and lamb transport emissions are swamped by other sources, including the methane produced by the digestive systems of cows and sheep, the clearing of land for grazing, and managing manure.

“For those categories, like red meat consumption, it definitely matters more that we reduce them in the first place,” Li says. “To replace red meat consumption with plant-based protein would definitely offer greater opportunity [to reduce emissions] than buying locally.”But for fresh fruit and vegetables, transport can add significantly to the overall emissions, especially when they are flown or trucked long distances in refrigerated vehicles. Li says buying local, seasonal greens is a useful step, and can bring other benefits related to healthy eating, community building and self-sufficiency.

FoodSwitch data – detailed health and environmental information on 25,000 types of supermarket products collated by the George Institute for Global Health – shows similar patterns.

Fraser Taylor, the managing director of FoodSwitch, says analysis of the data shows eating less meat overall, and swapping out beef and lamb for poultry or a vegetarian meal, is the “biggest single thing” people can do to reduce the emissions and environmental impacts of the food they eat.

But food miles still count, particularly for certain products, he says. Chocolate and coffee, for example, are often grown in remote locations. “They’ve got a heck of a lot of food miles associated with getting them here,” he says, and can contribute to land use change and deforestation in the places where they are grown.

Benefits of buying local Ceres Fair Food aims to support the local food system and the farmers and producers within it. The online grocery delivery service mainly sources its fruit and vegetables from market gardens and small farms dotted around Melbourne.

Chris Ennis, the social enterprise executive at Ceres, says supporting local growers and producers is as much about supporting the people working within the food system as it is about sustainability and lowering emissions.

The average age of farmers is getting older, with rising land prices and cheaper imports making it harder for people to get into farming, he says. Supermarket specials have added to the challenge by undercutting the cost of growing food.

“It’s really important to support new farmers, and existing farmers, to stay in the business,” he says. “When you support local, you know where your food comes from, you can have a connection direct to that farmer, you can have confidence that the farmer has looked after their land, you can also know that they look after the people who work for them.”As well as shortening the food supply chain, each Ceres Fair Food van delivers to 40 or 50 households, reducing last-mile emissions from people driving to the shops. Ceres offers reusable, refillable and returnable packaging, and collects customer soft plastics for recycling.

How to support local growers and producers For people wanting to reduce food-related emissions the United Nations guide to climate action recommends eating more plant-based foods, shopping local and organic, reducing food waste and composting.

Buying food closer to where we live supports the capacity of those economies to thrive, and is fundamental to health and wellbeing, Reis says. “This is about supporting local and independent growers, grocers, entrepreneurs, food businesses and food manufacturers to maintain and grow job security and economic prosperity in their regions.

“Support your local and regional food producers by buying their produce. You can look online for box systems and visit local markets,” she says.

“If you want to go very local, then have a look for organised food growing groups that support enterprise in urban agriculture, join a community garden, or supplement your diet with growing some herbs, veggies and fruit in your own back yard.”