Falling grain stocks and rising population spell disaster and demand debate

We humans are facing a new problem. As is inevitable within any closed system, our rapidly increasing impact on Earth's natural environment is beginning to cause systemic strain.1 In a remarkable “first” in human history, we have begun to change the composition of the atmosphere; and as a sign of planetary strain, the productivity of our main food producing ecosystems has apparently plateaued.2 3 4 5 Meanwhile, in absolute terms, world population is growing faster than ever.

Fertility rates have recently declined in most countries. But in a substantial and provocative article, King et al argue that this decline in fertility is too slow for the circumstances of today's world.6 The result, they say, is that some of the poorest nations are becoming “demographically entrapped”: the weight of their current or projected numbers exceeds the carrying capacity of their environment, and because they lack trade and migratory safety valves they face starvation, disease, or fratricide.6

The authors believe that officialdom and academia are blind to, or frightened by, the stark implications of entrapment. The topic, they say, is taboo. The official paradigm maintains that a steady global convergence towards the norm of a two child family will achieve an eventual balance between food and mouths. But King et al read the situation differently. After three decades of Green Revolution, dependent on high inputs of energy, water, and chemicals, the per capita production of grain (by far the world's dominant food item) has, since the late 1980s, begun to …