Credit: Jim Wehtje/Photolibrary

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PESTICIDES HAVE ALSO grown safer as regulatory authorities raise the bar and chemical companies oblige. In August 2006, after a 10-year review of pesticide safety, the U.S. Environmental Protection Agency (EPA) recommended cutbacks on the use of several pesticides – but these were overwhelmingly to protect against accidental workplace poisonings. "For the chemicals that are currently listed, I'm very confident that there is no risk to the general population through the diet," says Jim Jones, director of the agency's pesticide program.

There was also relatively little concern about the impact of pesticides in the environment. One exception was lindane, an organochlorine which accumulates in animal fat and is now largely restricted. This was deemed to pose a risk to indigenous people living above the Arctic Circle because of their high-fat diet. As far as the agency is concerned, the current batch of allowed agricultural chemicals are safe for consumers and the environment.

It's almost an axiom that pesticides are to blame for our major ecological problems. But once again, finding the evidence turns out to be a little difficult. Like many of today's environmental warriors, the University of Melbourne's Richard Roush was called to arms after reading Carson's Silent Spring. But after 30 years working in land management and sustainability, he thinks it's finally time to admit victory in the war on pesticides. "We've come a long way since Silent Spring… I am hard-pressed to think of a case where we can now attribute an environmental disaster to pesticide use."

In fact the only one that sprang to mind for Roush was a case of pyrethroids and fish abnormalities (pyrethroids are a synthetic version of plant-derived pyrethrins; the source turned out not to be not agriculture, but urban gutters. The finding stunned Roush. "Farmers have been trained for 20 years not to use chemicals where they could wash into streams; the problem was city people using pesticides to control household pests in a frivolous way."

Some of the blame for frog declines is often laid at the feet of agricultural pesticide run-off, but nailing such a link has proved elusive. In fact, frog losses from California's high Sierra have been much more convincingly linked to trout introductions. And chytrid fungus has proven the more likely culprit in many other cases of frog declines (see "Amphibian annihilation", p72). "[As far as frog extinctions go], I am much more concerned with global warming and the encroach of exotic species than pesticide run-off from farms," says Roush.

Environmental groups such as the World Wide Fund for Nature seem to have tacitly acknowledged that the judicious use of chemicals is the sustainable way to go. In 1996, they formed the non-profit group Protected Harvest with Wisconsin potato growers and the University of Wisconsin. Its goal: to develop ecologically sound principles for potato farming. The farmers reduced their use of chemical and natural pesticides using the principles of IPM and they also became better custodians of their non-farmed land by introducing native species and maintaining biodiversity.

"We're just starting to see market penetration as larger corporations get interested," says Deana Knuteson, a former University of Wisconsin entomologist who is now an education officer for Protected Harvest. With their high yields and good economic returns, she says they are confident about being able to expand to other vegetables.

ACCORDING TO VACLAV SMIL, an agronomist at Canada's University of Manitoba and an expert on the history of nitrogen fertiliser production, about 60 per cent of people today are fed thanks to the use of artificial nitrogen fertiliser.

Take that away, and all that nitrogen has to be produced organically – effectively using land to produce manure rather than food. Alex Avery, director of food research and education at the Hudson Institute, a conservative U.S. think tank, estimates that this would require doubling the amount of land now in cultivation. That would mean tearing down our remaining forests, he argues.

Even so, the poor yield of organic farming means that food production would be a major problem. In Australia, for instance, organic farming yields 50 per cent or less per square kilometre because of pest problems and phosphate-depleted soils. (Phosphate is locked away in the ancient clays; conventional farmers help themselves to highly soluble chemically-made superphosphate. Organic farmers can't use a chemical, so they use poorly soluble rock phosphate.)

In the late 1990s, Denmark seriously considered converting to 100 per cent organic agriculture. A report chaired by Svend Bichel, a former president of the Danish Society for the Conservation of Nature, concluded that should this occur, food production would drop by half.

There is one way the world can feed all the billions alive today with organic farming: we all go vegetarian. Half the world's grain is grown for cattle, and this is undeniably a highly inefficient use of soil, farming land and resources. But the reality is that the demand for meat, is – thanks to the growing wealth of developing nations – forecast to double by 2030.

Popular or not, it's clear that organic food is not necessarily healthier, nor more sustainable or better for the environment. With the Earth's climate changing fast, and the human population heading for nine or 10 billion, we need solutions based on scientific evidence rather than faith and good intentions.

The boutique organic foods café is a great place to enjoy the romantic idyll of traditional farming and natural foods, but when it comes to the reality of feeding the world, one would have to agree with Roush: "If improving sustainability and reducing the environmental footprint is the goal, we need to be prepared to use the best tools we have."

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