Professor Lord Krebs, Principal of Jesus College, told the Oxform Farming Conference that organic farming does not necessarily equate to environmentally friendly farming. He explained that organic farming is generally less productive per hectare meaning more land is needed to produce a certain amount of food.

"Converting land to agriculture, especially arable farming, results in the release of large amounts of carbon, so from the point of view of reducing greenhouse gases, organic farming might actually be a worse option than conventional farming," he added. Thus, he suggested that other forms of agriculture could also be harnessed to mitigate the effects of climate change. "Some evidence suggests that genetically modified, herbicide tolerant crops, facilitate minimum tillage agriculture, a further reason for encouraging their acceptance by the food industry," he said.

"But if we look at the big picture, there's no doubt that we are going to need all the appliance of science that we can muster, if agriculture is to rise to the challenge of feeding the world in a changing climate with diminishing resources. In short, we are going to have to produce more with less," he stressed.

Prof. Krebs served as Chief Executive of the UK Natural Environment Research Council and was the founding Chairman of the UK Food Standards Agency.

Read the complete transcript of his speech at http://www.ofc.org.uk/files/ofc/papers/frank-parkinson-lecture.pdf.