London, Feb 7 - Supermarkets are scrambling to capture the millions of "green" pounds spent by increasingly environmentally aware shoppers.
Farmers' markets across the country are buzzing with conscientious customers buying locally grown knobbly carrots and leeks pulled straight from the soil.
With the threat of climate change racing up the global political agenda, Britons are going green when they shop. And their sights are set on food miles.
"The concept of food miles has absolutely rightly entered into people's consciousness in Britain," says Bill Vorley, head of the sustainable markets group at the British International Institute for Environment and Development (IIED) think-tank.
The idea of reducing food miles seems straightforward -- simply buy produce which has travelled the shortest possible distance from farm to plate.
However, just as British consumers' enthusiasm to cut food miles is growing, some experts are warning that an over-simplistic view of the issue risks doing more harm than good.
They are urging policymakers not to rush blindly into formulating "buy-local-only" campaigns for consumers which could prove disastrous for many poor African food producers.
"I'm an advocate of local food, and I do think we need to re-localise our food procurement rather than hauling it up and down the motorways," says Vorley.
"But we are warning against allowing environmental arguments to trump the case for development -- especially when it guides decisions by policymakers or consumers that are going to have very little impact on our overall carbon footprint."
STRAWBERRIES AND SCHOOL RUNS
According to Britain's National Consumer Council (NCC) about 10 percent of the carbon dioxide emissions associated with British food transport come from air-freighted goods.
In a recent paper, the NCC said the carbon damage from air-freighting just one small punnet of New Zealand strawberries to Britain was equivalent to the CO2 emissions from 11 average school runs, made by parents driving their children to school.
The problem, experts say, is that consumers keen to do their bit for the environment but as yet unaware of the complexities of the debate are shopping with a simplistic "local good, foreign bad" attitude.
As long as the apples, carrots, broccoli and leeks are produced in Britain, they can be bought in abundance with a clear conscience, the thinking goes. But if the label says they come from Israel, Kenya or New Zealand, only a carbon criminal would dare take them to the checkout.
However, some argue that fair miles, not food miles, should be the criterion by which consumers judge the contents of their shopping trolleys. Specifically, fresh fruit and vegetables from sub-Saharan Africa, on which Britons spend more than a million pounds a day, should be considered more carefully.
"Many products which come to us from Africa are giving some of the poorest people in some of the poorest countries in the world a chance to earn a decent living," said Harriet Lamb, executive director of the Fairtrade Foundation, an independent certification body that guarantees poor producers in the developing world a fair price for their goods.
"People have to be careful in assessing the carbon footprint of a product, because it may well be that some products (from Africa) may actually have a smaller carbon footprint and a greater social impact than the same product grown in commercial greenhouses in Britain or the Netherlands."
A MILLION LIVELIHOODS
Lamb and Vorley warn consumers against feeling a false sense of environmental virtue if they avoid air-freighted products.
Cutting out products from sub-Saharan Africa would reduce Britain's overall contribution to global carbon dioxide emissions by just 0.1 percent, they say.
"And it's something like a million livelihoods that depend on us (in Britain) enjoying fresh fruit and vegetables from sub-Saharan Africa," says Lamb. "Let's make sure we're not making poor people in poor countries pay the price."
According to Stephen Mbugua, vice-chairman of the Fresh Produce Exporters Association of Kenya, that is not happening yet, but it is a great fear for the future.
"So far so good, we've not had any serious impact from this, (but) if there was a serious campaign, it certainly would affect our sales," he told Reuters in Nairobi.
Lamb quotes John Kanjangaile, export manager of a group in Tanzania called the Kagera Cooperative Union (KCU), speaking at a public meeting in Britain where he was asked about the potential environmental damage caused by his export business.
His reply was unequivocal: "With the deepest respect, the farmers in the villages where I come from don't have televisions, they don't have refrigerators, they don't have even one car, let alone two, they don't have motorbikes, they've never even been to our country's capital let alone flown all over the world on holiday -- so don't ask those farmers to pick up the cost of environmental problems you in the industrialised West have caused."