Contemporary global population change

Abstract

The twentieth century can be characterised as the demographic century. The world’s population grew more than three fold from 1.8 billion in 1900 to 6.07 billion in 2000. The current century will see the stabilisation of the global population and the speed with which this will occur will be of considerable significance for the environment, resources and the levels of living enjoyed by the world’s population. The slow down in the rate of growth of the world’s population from a peak of over 2 percent in some years of the 1970s to a current level of around 1.3 percent has been one of the most profound global changes of the last three decades. As Table 1 shows, it took several million years for the globe’s population to increase to one billion but each successive billion took increasingly fewer years until the last (sixth) billion was added in 12 years. However, the seventh and later billions will take increasingly longer periods. This paper summarises the findings of the latest biannual revision of world population projections made by the United Nations Population Division (2003a). It is worth noting that these projections are not intended as forecasts but indicate the population outcomes of a number of well defined and plausible (but hypothetical) scenarios of demographic change.