There is a debate about whether we should buy food from poor countries – which helps farmers, but might damage the environment. Well-meaning people are torn.
Ideally, the price of food in the shops would reflect the full social marginal cost of producing it and transporting it. So beans from Kenya would be more expensive if they use up more of the world's resources – including carbon emmissions from transport – than beans from a Spanish hothouse. If taxes were levied at levels and in ways that reflected externalities such as pollution, then we could let the market decide.
In the meantime, should we be buying food imported from Africa? I think we should, for three reasons.
First, it is not clear that food that has travelled a long way is worse for the environment than food grown locally. For many products, the energy needed to grow food locally – such as tomatoes in a hothouse – is more than the energy needed to grown them where the sun shines, even when you take into account the energy needed to transport them. Flowers grown in European greenhouses result in more CO2 emmissions than flowers grown in Africa and flown in.
Second, the energy needed to transport food is a tiny proportion of greenhouse gas emissions. It is way less important than, for example, putting your appliances into standby mode, or making one fewer business trip a year.
Third, millions of people depend for their livelihoods – and that of their children – on growing and selling food and flowers for the UK market. UK consumers spend a million pounds a day on food and vegetables from African farmers. If we deny Africans the opportunity to trade their way out of poverty by refusing to buy their agricultural products, then we will consign another generation of Africans to poverty and handouts from the rich. In Kenya, where half the population lives on less than 50p a day – Kenyan farmers can earn £1000 a year by growing fine beans. Tanzanian famers earn twice as much selling baby corn to UK supermarkets as they do selling maize locally.
More than two thirds of Africa's poor depend on agriculture for their livelihoods. In our determination to tackle climate change and reduce carbon emissions, let us start with sacrifices we can easily make ourselves, before we deny them the chance of a decent life.