Can GM crops feed the hungry?

The initiative is under the supervision of Richard Sayre from the Donald Danforth Plant Science Center in the United States.

Sayre rejects Gurian-Sherman's argument: "We know our cassava can help people," he says. "Initial estimates are that, in the first round of production, 35,000 lives will be saved in Nigeria. The long term impact is millions of lives saved."

Such claims are beguiling, but what about the cost when there's a limited international pot from which to fund nutrition?

Gurian-Sherman argues that the costs are so high that efforts should go elsewhere. A new biotechnology crop, he says, could cost up to US$100 million to produce (excluding regulatory costs) while the same crop improved through traditional methods would cost US$1 million.

In the case of C4 rice, the development costs are vast, says Sage.

"It is extremely expensive work," he told the AAAS meeting. "In order to create a sustained programme it needs US$10 million a year."

But, he argued, "it's cheap compared with the benefits". C4 rice could, he says, increase yield by 50 per cent - and the benefits of that are in the trillions of dollars.

The C4 project must therefore be viewed in the long term to understand its benefits. It will take two to three decades to come to fruition but could help solve the food challenges of 2050, he said.

So perhaps by 2050, with biosafety frameworks in place, resistance to GM subdued by the growing trouble of world hunger, and comprehensive GM solutions that solve a host of deficiencies in a single plant, GM might solve the problem of malnutrition?

Is GM a crude solution?

But there is still one major objection - that the problem of poor nutrition is so complex that it is crude to think it can be solved by GM.

The poor don't get enough food for a number of reasons: infrastructure, such as poor roads along which to take their goods to market; lack of fertiliser; lack of training in farming methods.

The rise of monocultures has reduced the variety of their diets. Land is distributed inefficiently or unfairly with the poor pushed onto unproductive land - and this requires legal reform followed by implementation. Popping a gene into a tomato is not going to solve these problems, it is argued.