Science in Society Archive

Food Miles and Sustainability

What’s behind the statistics and what should be done? Dr. Mae-Wan Ho and Rhea Gala

Food miles an indicator of sustainability

Food transported across the world burns up a lot of fossil fuel and contributes to global warming. “Food miles” - the total distance in miles the food item is transported from field to plate - has become accepted as a convenient indicator of sustainability, and has led to a general movement towards local production and local consumption in order to minimize them. This raises fundamental questions about the sustainability of the globalised food trade and the increasing concentration of the food supply chain and distribution in the hands of fewer and fewer transnational corporations.

UK’s Department of the Environment, Food and Rural Affairs (DEFRA) has commissioned a report to look into The Validity of Food Miles as an Indicator of Sustainable Development, which was published in July 2005.  The company commissioned to do the report was AEA Technology, formerly part of the United Kingdom Atomic Energy Authority and now a private sector company that was floated on the London stock exchange in 1996.  Given the narrow remit of the report, it nevertheless came up with some damning evidence against the dominant food system. The question is whether the political will is there to move forward from the discredited model.

Causes for the increase of food miles correctly identified

The report correctly identified the five most striking changes in the UK food production and supply chain in the last fifty years that have greatly increased food transport.

  • Globalisation of the food industry with increased imports and exports and ever wider sourcing of food within the UK and abroad
  • Concentration of the food supply base into fewer, larger suppliers, partly to meet demand for bulk year-round supplies of uniform produce
  • Major changes in delivery patterns with most goods now routed through supermarket regional distribution centres using larger HGVs (heavy goods vehicles)
  • Centralised and concentrated sales in supermarkets where a weekly shop by car has replaced frequent pedestrian shop visits

These trends all add to food miles.  Since 1978, the annual amount of food moved by HGVs in the UK has increased by 23 percent with the average distance for each trip also up by 50 percent. 

The report stated, “The rise in food miles has led to increases in the environmental, social and economic burdens associated with transport. These include carbon dioxide emissions, air pollution, congestion, accidents and noise. There is a clear cause and effect relationship for food miles for these burdens – and in general higher levels of vehicle activity lead to larger impacts.”

It was against this background that DEFRA commissioned the study.

Scope of the report limited

The study was meant to:

  • Compile a food miles dataset covering the supply chain from farmer (both in the UK and abroad) to the consumer in 1992, 1997 and 2002.
  • Assess the main trends leading to the increase in food miles at home and abroad
  • Identify and quantify the environmental, economic and social impacts of food miles
  • Develop a set of indicators which relate food miles to their main impacts on sustainability

These tasks are narrowly based and treat transport in isolation from the rest of the food cycle.  The energy-intensive globalised industrial model that is accepted as given, and indeed actively promoted by the government and the food and drinks industry, inevitably entails a massive food transport system. 

A more holistic and useful remit for the study would have been one that looked at the energy demands of the whole industrial farming and food model, including its specialized transport needs against those of a localised organic, energy conscious model that prioritises energy conservation and minimizes waste (see “Sustainable Food Systems for Sustainable Development” SiS27). This would have sharpened the focus on the costs/benefits of the two food strategies and allowed the government to choose more rationally the one that is in the interests of the people and the environment that it currently only pays lip service to.

The study finds, unsurprisingly, that a single indicator based on total food miles is inadequate. That’s because some miles such as air miles cost more in energy and carbon dioxide emissions; and others, such as HGV miles, cost more in terms of infrastructure damage.  So a “suite of indicators” is suggested.  Nevertheless, the study does admit that “Food transport has significant and growing impacts”, and goes to some lengths to document these.

Food transport has significant and growing impacts

Food transport accounted for an estimated 30 billion vehicle kilometres in 2002 of which 82 percent were in the UK; it accounted for 25 percent of all HGV kilometres in the UK and produced 19 million tonnes of carbon dioxide, of which 10 million tonnes were emitted in the UK; almost all from road transport.  This represented 1.8 percent of the total annual UK CO2 emissions, and 8.7 percent of the total emissions of the UK road sector.

Transport of food by air had the highest CO2 emissions per tonne, and is the fastest growing mode. Although air-freight of food accounts for only 1 percent of food tonne kilometres and 0.1 percent of vehicle kilometres, it produces 11 percent of the food transport CO2 equivalent emissions.

The direct social, environmental, and economic costs of food transport are estimated at over £9 billion each year, and are dominated by congestion. The social cost of congestion is estimated at £5 billion. Accidents lead to social costs of £2 billion per year, and greenhouse gas emissions, air pollution, noise and infrastructure cost a further £2 billion.

The report is in no doubt that “The total costs are very significant compared with the gross value of the agricultural sector of £6.4 billion, and the food and drink manufacturing sector of £19.8 billion.”

In other words, the £26.2 billion made by agriculture and the food and drink industry involve externalizing £9 billion (34 percent) of the costs, largely to the taxpayer. This is an underestimate, as the report stressed that impacts due to air transport have not been included.

These statistics, dire as they are, only hint at the scale of the real problem both at home and abroad, where identical produce is swapped across Europe and cash crops are flown in from the Third World for the furtherance of ‘free trade’, promoted by the World Trade Organization and other free trade agreements. 

The report should have sounded a warning for the urgent need to decrease these burdens on our environment and society at source.  National and international policies that aim to encourage a comprehensive shift to low input, organic local production and local consumption, and real investments into renewable energies in place of fossil fuels are among the most important options for making our food system sustainable.  This would substantially reduce CO2 emissions at a stroke, as well as wipe out the enormous externalized costs of food transport over long distances.

Recommendations for further work

The report ends with “Recommendations for further work”, the last of which was on policy, pointing out that the “impacts of any changes in food sourcing or food transport depend to a large extent on the policy framework, and on the response of consumers, producers and industry to those policies.”  It suggests a study of potential policies to include:

  • Sourcing food more locally where appropriate e.g. consumer awareness, public procurement, support for local food initiatives, strengthening UK suppliers
  • Reducing car food shopping e.g. home delivery, support for local and in-town shops, provision of safe cycle and pedestrian access
  • Reducing transport impacts e.g. cleaner vehicles, improved logistics, rail freight
  • Internalising the social costs of transport to reflect the costs to society of pollution, congestion, accidents, noise and so on, in the prices paid by transport users
  • Improving the wider sustainability of the food chain e.g. ethical trading, improved energy efficiency in the local food sector

This is a very partial list of useful policies that essentially leaves the existing food system untouched.

Reports commissioned by the UK government from private consultants cost the taxpayers £1 billion annually. They cannot be value for money if all they do is entrench governments in the very policies that have created the problems identified.

It is clear, from the causes of increased food transport identified at the beginning of the report, that policies are needed to minimize food import/export, to promote instead, national/regional food-sufficiency, and to reverse the concentration of food supply chains in favour of local shops and cooperatives run directly by farmers and consumers. In addition, there should be government subsidies and incentives for reducing carbon dioxide emissions on farms, and for farms and local communities to become energy self-sufficient in low or zero-emission renewables.

Article first published 21/09/05


  1. The validity of food miles as an indicator of sustainable development
  2. Final Report produced for DEFRA by AEA Technology, July 2005.
  3. ‘Advice from private consultants costs government £1bn a year.’  Marie Woolf.  The Guardian, 19 August 2005.
  4. Ho MW.  Sustainable food systems for sustainable development.  Science in Society 2005, 27, 33-35.

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