GM debate looms large at City Food Lecture

* The world needs to increase food production 50% by 2030 to feed a rapidly expanding population
* Global warming is real and will hit food production capacity, even in the northern hemisphere
* Water depletion is as big an issue as oil depletion, and better global governance will be needed as the tensions mount
* The commodity price hike of 2007/08 was driven to a large extent by the push to convert grain into ethanol
* Using wheat or maize to produce fuel creates as much carbon as fossil fuel and makes little sense
* Soil erosion is a massive problem in some parts of the world, though relatively simple responses can correct it
* These challenges are all interlinked

And then there was the old argument about GM technology versus organic farming.

Not surprisingly, Sir David was adamant that there was a "desperate need" for GM technology to help boost food production. He stressed that we need all the tools in the box, including good soil management as advocated by the organic lobby.

But rejecting one particular technology, especially one with such enormous potential as GM, made no sense at all. Had GM technology been used to develop flood resistant rice, rather than relying on conventional plant breeding, he said, numerous lives could have been saved in the past three years.

Not surprisingly, Patrick Holden of the Soil Association took a very different view, describing the dominance of a few varieties of GM crops in North America as "dangerous". We did not know how many people had been damaged by GMs "because the trials have never been done", GMs had not produced any yield gains and farmers had had to increase pesticide use after planting GM crops, he claimed.

I have to admit, I was far from convinced.

Patrick Holden may claim that GM foods could be damaging to human health, but where is the evidence? US citizens have been eating the stuff for the best part of 15 years and seem to be doing alright - better than the millions of people in Third world countries who go to bed hungry every night because they don't have enough rice to eat.

And while GM's may not yet be delivering specific yield increases, they have certainly been effective at protecting crops from insect and foliar diseases, so preventing yield losses. And farmers I've spoken to in the USA and Spain consistently tell me their dependence on pesticides overall is reduced as a result of growing GMs.

The Soil Association also points to the fact that GM seeds cost more than conventional seeds and this should serve as a warning to British farmers. But couldn't that just be because, like an Aston Martin compared with a Ford Mondeo, they are better?

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