At the Oxford Farming Conference, last week, the concerns over the growth in the global population and how to feed growing numbers at a time of climate change and diminishing land and water resources were at the forefront of the debate.

The question of the acceptability of GM foods was first raised by the UK Environment Secretary Owen Paterson who told the conference: "GM needs to be considered in its proper overall context with a balanced understanding of the risks and the benefits.

"We should not however be afraid of making the case to the public about the potential benefits of GM beyond the food chain, for example, significantly reducing the use of pesticides and inputs such as diesel."

He added: "I believe GM offers great opportunities but I also recognise that we owe a duty to the public to reassure them that it is a safe and beneficial innovation."

While the Environment Secretary embraced the potential of genetically modified products, it was a former leading anti GM campaigner, Mark Lynas (pictured) in the Frank Parkinson lecture, who openly attacked the anti-GM lobby for not basing their arguments on scientific fact.

Mr Lynas, who in the early days of GM trials had actively ripped up crops and destroyed test fields, had his moment of enlightenment while researching the effects of global warming and climate change.

His research led him to base his climate change arguments on scientific studies and papers but the opposition lobby "denied the scientific reality of climate change".

Taking the scientific approach to GM he said: "I discovered that one by one my cherished beliefs about GM turned out to be little more than green urban myths.

"I'd assumed that it would increase the use of chemicals. It turned out that pest-resistant cotton and maize needed less insecticide.

"I'd assumed that GM benefited only the big companies. It turned out that billions of dollars of benefits were accruing to farmers needing fewer inputs.

"I'd assumed that Terminator Technology was robbing farmers of the right to save seed. It turned out that hybrids did that long ago, and that Terminator never happened.

"I'd assumed that no-one wanted GM. Actually what happened was that Bt cotton was pirated into India and roundup ready soya into Brazil because farmers were so eager to use them.

I'd assumed that GM was dangerous. It turned out that it was safer and more precise than conventional breeding using mutagenesis for example; GM just moves a couple of genes, whereas conventional breeding mucks about with the entire genome in a trial and error way."

He added: "We are going to have to feed 9.5 billion hopefully much less poor people by 2050 on about the same land area as we use today, using limited fertiliser, water and pesticides and in the context of a rapidly-changing climate."

He said it has been estimated that there will have to be a 100 per cent increase in global food production to feed this increase in population.

"To quote Norman Borlaug: "I now say that the world has the technology - either available or well advanced in the research pipeline - to feed on a sustainable basis a population of 10 billion people. The more pertinent question today is whether farmers and ranchers will be permitted to use this new technology? While the affluent nations can certainly afford to adopt ultra low-risk positions, and pay more for food produced by the so-called 'organic' methods, the one billion chronically undernourished people of the low income, food-deficit nations cannot," Mr Lynas said.