Archbishop Dr Rowan Williams is living in cloud cuckoo land if he thinks we can make the UK self sufficient in food production and still allow consumers to enjoy the wide variety of fruit and vegetables they want. His call to mobilise Britain's gardeners and transform our gardens and parks into vegetable plots to feed the nation is ridiculous.

Around 60% of fruit and vegetables are imported into the UK, providing us with produce outside the UK season as well as varieties that simply cannot be grown in the UK. Research shows that some imported fruit and vegetables are grown in less greenhouse gas-intensive ways than the same products in the UK, with savings from greater efficiency outweighing the potential negative impacts of additional transport. While we would encourage greater production of indigenous foods in the UK, there's no need to restrict choice by excluding imported produce on the basis of its carbon footprint. We can enjoy a wide variety of fresh produce all year round, irrespective of its origin. The consumption of fruit and vegetables accounts for only 2.5% of the UK's greenhouse gas emissions in total.

With rising levels of obesity, we should not be doing anything that limits choice. Agricultural growth is essential to economic growth in Africa; imports to the UK from Kenya alone are worth £100m, with trade directly employing 135,000 people. There is no evidence fewer aircraft would fly if less fruit and vegetables were imported, as at least 60% of air-freighted fresh produce comes to the UK in the bellyhold of passenger aircraft. Air-freighted imports of fruit and vegetables account for 0.2% of total UK greenhouse gas emissions.

We do need to look at ways of tacking climate change, but the concept of 'food miles' is confusing and generates a false sense of eco-security. Instead let's look at the carbon footprint of the whole product supply chain and give consumers meaningful advice with which to make informed decisions.

Nigel Jenney, chief executive, Fresh Produce Consortium