Every morning, cargo planes filled with carnations and roses depart from Nairobi and land in Amsterdam to be sold at the world's largest flower market. The 21 million flowers then journey on to destinations as scattered as London, Moscow, Beijing and San Francisco.

Flowers, food and drink - meats, fruits, vegetables and even wines - now criss-cross the globe to an extent unimaginable just 50 years ago. Billions of poor people can only eat whatever is grown locally, but the relatively affluent enjoy seasonal produce like strawberries, tomatoes and peas all year round. South African grapes, Australian lamb, Guatemalan bananas and Argentine beef regularly end up on supermarket shelves and dinner tables, alongside Chilean apples and Moroccan beans.

Transport is faster and more reliable nowadays. But it is also subsidized by a lack of taxes on airline and shipping fuels. The environmental costs of pollution - including greenhouse gases that cause global warming - are not included in the prices paid for much of the food in the shops.

There are 25 million milk-producing animals in Mongolia, but the shops used by wealthier people there mainly sell German butter. Britain imports 430,000 tonnes of butter from its neighbours in the European Union (EU) - while exporting roughly 470,000 tonnes to those same countries.

The EU imports 72 per cent of all apples on the world market, and its supermarkets generally stock just four or five types of them. Yet more than 2,300 regional varieties of apple grow there.

One study, looking at a typical Sunday lunch near Leicester, England, found that the beef had travelled 21,462 km from Australia, the potatoes 2,447 km from Italy, the carrots 9,620 km from South Africa, the beans 9,532 km from Thailand and so on, through the courses, for a total of 73,448 km. Every continent contributed to the lunch table, but all the food could have been produced and bought locally.

People are starting to question the logic of all this. We could live just as well and interestingly using more locally produced goods. Drives to buy locally have sprung up - from Governor Arnold Schwarzenegger's urge to 'Be Californian: Buy California Grown' to the 'Proudly South African' campaign and farmers' market movements across Europe and the United States. Favouring local consumption as a way of returning to regional pride and cultural roots, as well as good environmental practice, is growing rapidly.

Buying foods locally can also build community and reawaken understanding of connections between people, land and harvest cycles. Cooking fresh ingredients - as advocated by the Italian-founded Slow Food Movement - encourages 'taste, tradition and the honest pleasures of food'.

There is an old environmental slogan: 'Think globally, act locally'. Maybe it is time to supplement it with a new one: 'Think globally, eat locally'.