Why going organic could cost the earth

A government report claims that, despite its eco-friendly image, some organic farming creates greater pollution and contributes more to global warming.

According to the study, certain organic foodstuffs — such as milk, chicken and tomatoes — produce more greenhouse gases, create more soil and water pollutants and require more energy and land for their production than those farmed by conventional methods.

As the first major report on the environmental impact of organic food production, the document will reignite the debate over the £1.6billion industry, which grew by almost a third last year alone and now accounts for four per cent of farm produce.

The market is forecast to be worth £2.7billion by 2010.

"You cannot say that all organic food is better for the environment than all food grown conventionally," said Ken Green, professor of environmental management at Manchester Business School, who conducted the research with the Department for Environment, Farming and Rural Affairs.

"If you look carefully at the amount of energy required to produce these foods, you get a complicated picture.

"In some cases, the carbon footprint for organics is larger."

The report looked at Britain's 150 top-selling foodstuffs, as identified by supermarkets, and assessed energy use, the effect of by-products from farming, and the impact of processing and packaging of both methods.

It concluded that there was "insufficient evidence" to prove organically farmed food was better for the environment.

"In particular, organic agriculture poses its own environmental problems in the production of some foods, either in terms of nutrient release to water or in terms of climate change burdens," the report said.

For example, because organic chickens were reared for longer than battery hens, they had a larger environmental impact.

The study comes as organic farmers reel from last month's comments by Environment

Secretary David Miliband, who suggested organic food was simply a "lifestyle choice" and there was no evidence it was a healthier option for consumers.

Even the Government's chief scientific adviser, Professor Sir David King, has previously expressed his reservations about its overall benefits compared with chemically treated produce.

The findings of the report are, however, unlikely to sway advocates of organic farming, who maintain that it is still better for "biodiversity" than intensive farming.

The Soil Association, the country's main organic certification body, conceded that organic farming was not always energy-efficient, citing as examples poultry farming and growing vegetables out of season.

However, it claimed these disadvantages were vastly outweighed by other factors not assessed in the Defra study, such as animal welfare and soil conditions.

Around 350 pesticides are allowed in conventional farming, and an estimated 4.5billion litres of chemicals are used on British farms each year. Many consumers say organic food tastes better but it is, of course, more expensive.

For example, an organic chicken costs about £8.50 in a supermarket, almost three times the price of its non-organic counterpart.