Shoppers should not assume that buying food from abroad is worse for the environment than buying from the UK. It's not that simple. Furthermore, the livelihoods of a million African farmers are threatened by misunderstandings about the "food miles" debate.
Certainly, the environmental footprint of what people consume does matter, but so does the development footprint. It seems a dilemma: whether we in rich countries should help poor countries trade their way out of poverty by buying their exports, or boycott them and only buy local.
But even if the debate is muddied, the facts are clear. In Kenya, for example, carbon emissions are 200kg per head of population, while in the UK they are almost 50 times that. Air-freighted fruit and vegetables from Africa account for less than one-tenth of 1 per cent of the UK's greenhouse-gas emissions. Why should developing countries be punished for the damage that our lifestyles cause?
If we boycott goods flown from developing countries to the UK, we jeopardise one of the best chances these countries have to earn their way out of poverty. This would seem to fly in the face of what the public vocally demanded three years ago, when the world pledged to make poverty history. Not only that, but it runs counter to global efforts in the so-called Doha round to lower trade barriers for the world's poorest countries.
Food miles do have an environmental and social cost, but most of that cost - about 85 per cent - comes from UK roads. We have to consider the entire life cycle of a product in order to assess its environmental impact, and not just the transport element. To this end, the UK is working towards a global system for pricing carbon so that the price of food and other products will fully reflect their impact on the environment.
Many products flown in from developing countries such as those in Africa have lower carbon emissions than produce that relies on energy-intensive farming techniques used in Europe, such as heated greenhouses. Producing roses in the Netherlands, for example, can use more energy than producing them in Kenya. Driving six miles to shop may emit more carbon than the cost of flying food to the UK.
A few months ago, the Soil Association sought opinions on whether it should remove organic status from air-freighted foods. But 80 per cent of the trade affected would be from developing countries, so such a move would harm business from African countries whose organic production is on the rise. Such exports to the EU now represent $100m a year.
The result has been a sad compromise. While the good news is that air-freighted produce from developing countries can keep its organic status, it must also meet "Fairtrade" standards, adding extra costs of certification.
I recently met Ernest Abloh of Blue Skies Ghana, who is against a ban. He provides support to more than 150 farmers, over half of them organic, and claimed damage had already been done by focusing on only one stage of production, airfreight, and not the wider issue.
It is clear that consumers and industry want to help boost developing countries' trade. The rise of fair trade and membership of the Ethical Trading Initiative are positive trends. Another very positive trend is the commitment of the Co-op "to reduce carbon but never at the expense of the world's poorest''.
The government, too, is stepping up our work on ethical trade. As well as supporting ethical and fair-trade initiatives, it is nurturing business partnerships between the UK and Africa.
Last month, directors from the UK's main supermarkets and food manufacturers got around the table, apparently for the first time, to discuss their role in tackling global poverty. The Department for International Development set up this series of meetings with the aim of getting discussions going on opportunities to scale up trade with poor countries that is both sustainable and fair. Another DfID initiative is its new £2m fund to nurture UK-African retail and food partnerships. This should also serve to stimulate investment, ideas, and better information for shoppers about food miles.
One idea this fund might test is a "low-carbon pineapple" from Ghana. Pineapple farmers such as Kweku Ayuba are worried about the impact of the food miles debate on their trade. Such a project would aim to show that the pineapple export business can measure and reduce its carbon footprint, saving costs and improving competitiveness.
There is clearly consumer and industry support for farmers like Kweku. But we need more. Developing countries cannot afford to be silenced or lose out from a misinformed food miles debate. The development, environmental and ethical advantages of trade with Africa need to be heard. Otherwise, helping our neighbours fight poverty, rather than doing right, will be perceived as wrong.
Gareth Thomas is minister for trade, consumer affairs and development