Growing food and bringing it to our tables accounts for about 20% of UK greenhouse gas emissions. Including the impact of the deforestation elsewhere that is driven by UK food demand, the figure may rise to around 30%.(1) If developed countries are to reduce their emissions by four fifths by 2050, it is painfully obvious that food production and consumption habits will have to change dramatically. A recent report on the emissions reductions obtained by people participating in ‘The Fife Diet’, a programme designed to increase willingness to buy only locally-produced food, show just how difficult emissions reductions are likely to be. (2) The two key problems are now well known. Food production systems in the developed world tend to produce about one unit of energy for every ten units of energy input. Therefore the recent - only possibly humorous - suggestion that the UK government should introduce electricity generating treadmills into prisons would therefore add to total energy demand, not reduce it. To remain at a stable weight, prisoners would need to eat more calories and these calories might take ten times as much energy to produce as the maximum amount of electricity generation derived from the treadmill. We need two kilowatt hours or so of energy a day to fuel ourselves but it currently takes 25 kWh to produce this.

Second, the footprint of food is dominated by that of meat and dairy products. Most estimates show that over half the emissions from a Western diet derive from meat. As people get richer, they demand more animal protein, increasing both direct emissions, particularly of methane, and also heightening the pressure to convert forest to food production. Stabilising and then rapidly reducing global emissions from the food production chain is appallingly difficult to reconcile with increased levels of prosperity.

The Fife Diet is a successful and well-regarded experiment to push people in eastern Scotland into thinking actively about the source of the food that they buy. It is similar to the Canadian 100 mile diet. (www.100milediet.org), which asks individuals to commit to only buying food grown in the local area. It therefore isn’t just about local food, but also about buying seasonal produce and so help get a fuller sense of the connection between what we eat and how and where it is produced.

From a small base, the local food movement is gaining strength around the prosperous world. The detailed survey of Fife Diet members showed that the greenhouse gas emissions from the food that they bought, cooked and then disposed of are lower than the national average. But the impact of merely buying locally is small.

Greenhouse gas emissions (CO2e) from food, per year per person

2.8 tonnes 2.1 tonnes

UK adult average Fife Diet members

The lower number comes not from the energy-saving benefits of buying local, which provides only 8% of the reduction, but from the smaller amount of meat and dairy eaten by the survey respondents. The impact of the higher level of organic food consumption, lower wastage and greater food production at home of the Fife Dieters did not produce a significant cut in their emissions compared to the UK average. The lower meat consumption cut emissions by over half of tonne, about three quarters of the total reduction. But at 2.1 tonnes a head, the Fifers still had emissions from food consumption greater than total per capita allowance for 2050. And it has to be said that the greater eco-awareness of the Fife diet people probably meant that they already had a much lower food footprint before becoming members.

The conclusion is a painful one. Getting down to about 0.5 tonnes a head by mid-century will almost certainly require a portfolio of measures that combines near-total decarbonisation of the energy sources in food production (eg the farm tractor runs on electricity or sustainably produced bio-diesel) and a radical change in consumption habits. Vegan food, produced on largely animal free farms, will become the dominant source of nutrition if we are to meet our targets. (Unless, that is, we find a way of artificially producing meat in vats). Importantly, several recent studies show that vegan food that is manufactured to look/taste like meat (such as industrially produced tofu) often has a ‘foodprint’ not dissimilar to its meat equivalent. The food we will eat will have to be largely unprocessed wholefoods, such as complete grains. (3)

In other words we will need both changes in consumption patterns and substantial advances in technology. Neither shifting shopping patterns (eg just buying seasonal food from the region and cutting out most meat) nor relying on technological change will be enough. We need both. The remaining problem is that the eco-greens who support local farming, mild vegetarianism and organic techniques are a very different set of people to the urban techno-greens who lead the drive for total decarbonisation of energy production, perhaps through nuclear power or tens of thousands of wind turbines in the Fife countryside. Building consensus over food is going to be as difficult as over energy supplies.

(1) These are figures from a variety of sources but are in line with the recent report from WWF entitled ‘How Low Can We Go’.

(2) Fife Diet: Carbon foodprint (sic): comparative study and member analysis, August 2010.

(3) As a failed vegan, I find the research and advocacy at www.stockfreeorganic.net to be powerful and highly informative.