I picked up One Billion Hungry by Gordon Conway with the hope of some reasonable analysis of the world’s population problem. To any reasonable person the quantity of food must be balanced with the number of individuals needing sustenance from that food. That being an obvious necessity for feeding a population — any population — it makes sense to check the index for the author’s links to that discussion. In a ten-page fine print index there was exactly this: “population growth, 8-9, 30.” In a 439 page book that is a red flag to any serious inquiry into balancing the need for food to the supply of food. This is especially a serious flaw when we consider that in the last one hundred years the human population has grown (really I should say exploded but I will remain calm) from under two billion to an excess of seven billion. That is roughly three and a half times more people living on exactly the same Earth. Where did all of the food come from to feed 3½ times as many people? The usual answer is the Green Revolution, which means that a given species of plant was producing more edible food for humans. That excess can be created when a small percentage of a plant’s resources are used to generate food, but at present a large percentage of plant resources are being eaten. That means we won’t be having a second Green Revolution because the plants can’t convert more than all of their biomass into something edible. Another problem with an unlimited increase in supply of food coming from the same soil is that a large percentage of that food energy comes into being because of petroleum products: farm equipment, fertilizer, transportation to market, and the infrastructure to do these things. There is talk of peak oil production, which means that our oil supply isn’t going to last forever, and in fact is unlikely to last at anything approaching our present prices for fifty years. That is optimistic and doesn’t take into account the increasing stresses caused by atmospheric pollution and other pollutions. If we can’t maintain the food production for the expected lifetimes of people now living, how can the author of this book expect to feed the additional billions he expects to inhabit the Earth in a few decades. With these worries in mind I dipped into those two pages where population problems are discussed.
On page 9, “This optimism is based on the experience of recent decades.” I will be eager to grant the last few decades have been wonderful in terms of food for humanity, and in fact will agree that it has been wonderful ever since the great bubonic plague of 1348. Furthermore, the overall quality of life for people is accelerating in a positive way and will continue to do so for a while, and all I am claiming is that it can’t and won’t last forever. The much touted demographic transition based on increased income and increased educational level of women is trotted out as a reason for our prosperity and decreasing the population explosion. But that argument is simply finding correlations with things that have happened recently, but it is unlikely to be predictive over a few decades of anything whatsoever. They could have made absurd comparisons, such as with the oil becoming used up over the last fifty years as a correlation with increased human prosperity. The Global Hunger Index (GHI) may be a reasonable way to measure the number of hungry people in the world, but measuring the number of hungry people for the last fifty years and observing that by their measure it has usually remained under one billion people doesn’t mean much when trying to estimate what will happen in the next fifty years. The next five decades must not only include more people, it must include the degradation of resources and the increasing cost of fuel to power the farming economy.
Meaningful prediction is based on causal factors and not on past trends.