Correction on land to feed the world

I have been in the habit of quoting something I recall Geoff Lawton saying to me in an interview along the lines that with permaculture we would only need 2% of the current arable land to feed the world. I have written this here and here. Most people tend to conclude from that statement that we only need 2% of the land to produce the same tonnage of food. By my own admission this seems pretty astounding so I emailed him for a clarification and he said that in fact we can “produce the same amount of nutrition on 2% of the equivalent area now used by the global industrial agricultural system”.This is a crucial difference and makes a lot more sense- especially when you consider the many over-fed but under nourished members of western civilisation.