Global population growth, food security and food and farming for the future

Abstract

At the start of agriculture 10 000 to 15 000 years ago, the estimated world population was between 1 and 10 million. It then grew to 300 million about 2000 years ago, and after a further 1600 years it doubled to 600 million; it has since risen from about 1.5 billion at the end of the nineteenth century to the present level of about 7 billion (Figure 2.1) (OECD, 2011). This recent rapid growth in population began in 1950, with reductions in mortality in the less developed regions; this resulted in an estimated population of 6.1 billion in the year 2000, nearly two-and-a-half times the population in 1950. However, with the recent declines in fertility in most of the world, the growth rate of the global population has been decreasing since its peak of 2.0% in 1965–70. There are significant international differences in the historic and predicted population trends according to the state of each country’s economy. During the transition from a subsistence rural economy to that of more developed economy, most countries’ populations go through a ‘demographic transition', a shift from high fertility and mortality rates to lower mortality, followed by declining fertility and a stable or even shrinking population. Global data show that people under the age of 25 now comprise 43% of the world’s population, reaching as much as 60% in some countries (Population Action International, 2011).