This is a guest post by Peter Goodchild, author of Survival Skills of the North American Indians published by Chicago Review Press. His email address is odonatus@live.com. This piece was previously published at countercurrents.org.

Only about 10 percent of the world’s land surface is arable, whereas the other 90 percent is just rock, sand, or swamp, which can never be made to produce crops, whether we use “high” or “low” technology or something in the middle. In an age with diminishing supplies of oil and other fossil fuels, this 10:90 ratio may be creating two gigantic problems that have been largely ignored.

The first is that humans are not living only on that 10 percent of arable land, they are living everywhere, while trucks, trains, ships, and airplanes bring the food to where those people are living. What will happen when the vehicles are no longer operating? Will everyone move into those “10 percent” lands where the crops can be grown?

The other problem with the 10:90 ratio is that with “low technology,” i.e. technology that does not use petroleum or other fossil fuels, crop yields diminish considerably. As David Pimentel showed in 1984 in his “Food and Energy Resources,” with non-mechanized agriculture, corn (maize) production is only about 2,000 kilograms per hectare, about a third of the yield that a farmer would get with modern machinery and chemical fertilizer. If that is the case, then not only will 100 percent of the people be living on 10 percent of the land, but there will be less food available for that 100 percent.