The flight of the humble pea
The Undercover Economist – FT Magazine 10 June
I am becoming a dab hand at turnip soup now that Family Harford eschews supermarket mange-tout in favour of a weekly organic box. I have to confess that I miss the marvellous mange-tout, bursting with freshness and rushed to me straight from Nairobi in a battered old 747.
The mange-tout is, sadly, now beyond the pale. My tree-hugging friends condemn the purchase of anything that has travelled what they judge to be excessively long distances – in the jargon, anything with too many “food miles”. The term echoes “air miles” and the distinct impression we get is that anything you buy outside a farmers’ market has been flown first class at terrible cost to the planet.
The truth is somewhat different. Hardly any food miles are, in fact, air miles. Just under half of them are customers driving to the shops, the rest are vans and lorries shipping food around on the roads. Air and sea miles are a rounding error – 0.1 per cent for air and 0.04 per cent for sea, according to a report on food miles commissioned by the Department for Environment, Food and Rural Affairs and published in July 2005.
Admittedly, the tiny proportion of food that is transported long distances by air does generate a disproportionate amount of carbon dioxide, the leading contributor to climate change. According to the same Defra report, 11 per cent of all carbon dioxide emissions from UK food transport comes from long-haul air cargo – that is, the mange-tout and its kin. Another report from Sustain, a campaigning organisation in favour of locally produced food, calculates that flying 1kg of mange-tout from Nairobi produces nearly 4kg of carbon dioxide – a striking and rather alarming figure.
But how alarmed should we be? To answer that, we need to know how much damage 4kg of carbon dioxide is likely to cause. The answer is almost certainly very little. Climate change might be catastrophic, but 4kg of carbon dioxide does not produce much climate change.
Polluters in Europe currently have to pay about 210 per tonne of carbon dioxide as part of Europe’s efforts to meet its obligations under the Kyoto agreement. That is less than one penny per kg of carbon dioxide. Perhaps that price, in a volatile market, is too low. A Government Economic Service paper on the social cost of carbon emissions recommends a cost closer to 225 a tonne of carbon dioxide. Even that is less than 10p for a kilogram of mange-tout, or a penny for a 100g packet. If consumers were forced to meet those costs – as in principle they should be – the sum would barely register. There are good environmental reasons to tax airline fuel, but such taxes are not likely to make food imports substantially more expensive.
No, the real hidden cost of the mange-tout is not the journey from Kenya, packed densely into an airplane hold to minimise costs. It is the journey you take in your people-mover to the high street or supermarket, and back again with a couple of small bags of shopping in the boot. According to the Defra report, more than two-thirds of the social cost of food transport comes from congestion and accidents, with the largest single contributor being the cars we drive to the shops.
Kenyan farmers need all the help they can get. The biggest risk of the outrage over food miles is that it is used to support those who want to protect domestic farmers against competition from foreign farmers who deserve a chance. The environmental case against the mange-tout is slim. I suggest that you buy as many as you like – as long as you cycle to the shops.