Organic's footprint

The quantity of cereals harvested in the world has trebled in 40 years [correction: nearly trebled in 50 years!], but the acreage planted to cereals has hardly changed at all.

(graph from my book)

That remarkable achievement is mostly down to the fact that most farmers now get extra nitrogen straight from the air, via ammonium factories, rather than from plants, dung and dead fish -- the `organic' way.

If the world was fed with organic food, it follows, we would need to cultivate or otherwise exploit far, far more land to get the plants, dung and dead fish to produce the same amount of food. As I submit to being preached at by organic farmers about their virtue, this fact keeps creeping into my head. Wholly organic farming means no rainforests or it means hunger and high food prices.

The organic folk usually reply by saying that their farms are better for wildlife on a local level. Well, now comes a comprehensive study of British farmland that says they are not even achieving that:

While there were more plants and butterflies on organic farms, there was no difference in the number of bees and there were 30 per cent more hoverflies on conventional farms. Organic fields contained more magpies and jays but 10 per cent fewer small birds such as yellowhammers, corn buntings, linnets, skylarks and lapwings.

(More magpies, fewer songbirds: Duh! Magpies predate songbird nests.)

The study (original paper behind a paywall, but abstract here) also confirms that organic farming uses up more land to produce the same amount of food:

It concludes that organic farms produce less than half as much food per hectare as ordinary farms and that the small benefits for certain species from avoiding pesticides and artificial fertilisers are far outweighed by the need to make land more productive to feed a growing population.

Last year saw another organic myth laid firmly to rest, when Alan Dangour did a huge survey of all studies purporting to test the health benefits of organic food and found:

Our systematic reviews found that there was no evidence of any important differences in the nutritional composition of foodstuffs grown using conventional and organic farming methods. There was also no evidence of nutrition-related health benefits from consuming organically produced foods.

Bruce Ames long ago (here and here) laid to rest the myth that pesticide residues in conventional food pose a risk to human health:

The pesticides in our diet are 99.99% natural, since plants make an enormous variety of toxins against fungi, insects, and animal predators. Although only 50 of these natural pesticides have been tested in animal cancer tests, about half of them are carcinogens. About half of all chemicals tested in animal cancer tests are positive. The proportion of natural pesticides positive in animal tests of clastogenicity is also the same as for synthetic chemicals.

Given that organic farms use crushed fish, flame-throwing weed control, copper sulphate pesticides, poorly paid labour, and given that it still it takes just about the same calories of fossil fuels to get an organic lettuce from a Californian farm to a plate in New York -- 4,600 versus 4,800 (numbers from Michael Pollan's Omnivore's Dilemma) -- can we please have a little less preaching of organic's holiness?

By all means eat organic food if you want to. But be honest and admit that, as far as the health of the planet is concerned, you are being selfish, rather than virtuous.