Duncan Green, Head of Research, Oxfam

Professor Tim Lang, who invented the idea of food miles, is a gifted campaigner. Lang has effectively challenged consumers to take action to curb the environmental destruction caused by daft practices like shipping bottled water to markets on the other side of the world. But what if you're one of the 1.5 million African farmers and labourers who grow flowers and vegetables for export, mainly to the UK?

In October, the Soil Association responded to concerns about food miles by saying it would only certify airfreighted products as organic if they also carried the fairtrade mark. Good for fairtrade, which we should all support, but wrong in terms of development, both on the grounds of equity and proportionality.

First equity: African farmers are amongst those least responsible for climate change, and yet they are being hit first and hardest by its effects - where's the justice in making them pay first to correct the results of our own carbon profligacy?

Second proportionality: While we acknowledge the impact that a growth in airfreight will have on carbon emissions, it's important to keep things in perspective. If everyone in the UK switched one 100W light bulb to a low energy equivalent it would, over a year, reduce CO2 emissions by five times the amount that would result from not purchasing fresh fruit and vegetables from sub-Saharan Africa. We should (literally) put our own house in order before boycotting African produce in the name of climate change.

Duncan Green, Oxfam's Head of Research