Wolfgang Lutz and his group at the Wittgenstein Centre for Demography and Global Human Capital in Vienna have suggested a different way to project the population. They call them multi-dimensional projections because instead of using just age and sex they also build in projected changes in other aspects of society--especially education--that can influence birth and death rates. In the 13 December 2016 issue of the Proceedings of the National Academy of Sciences (PNAS) they published projections that were built with the idea of the world meeting the United Nations' Sustainable Development Goals (SDGs). Several of those SDGs, if fully implemented, will lower both birth and death rates in predictable ways.
In the context of sustainable development, world population growth is sometimes called “the elephant in the room.” Many view it as one of the most important factors in causing environmental degradation and in making adaptation to already unavoidable environmental change more difficult (16–18). At the same time it is widely perceived as a politically sensitive topic (19), and indeed the 1994 International Conference on Population and Development explicitly opposed the setting of “demographic targets.” Fertility decisions are considered a private matter, with the role of the state being only to assure reproductive rights and to provide reproductive health services. It is presumably for this reason that the new SDGs do not mention population growth or fertility explicitly in any of the 169 targets. However, many of the goals and targets deal with factors that directly or indirectly influence fertility and thus population growth.Their projections produce the following results:
In this paper we endeavor to translate the most relevant of these goals into SDG population scenarios and thus quantify the likely effects of meeting these development goals on national population trajectories. The results show that meeting these goals would result in the world population peaking around 2060 and reaching 8.2–8.7 billion by 2100, depending on the specific SDG scenario (Fig. 1). This analysis quantitatively demonstrates that demography is not destiny and that policies, particularly in the field of female education and reproductive health, can contribute greatly to reducing world population growth.
In other words, there are strong positive reasons to make sure that all countries successfully implement the SDGs. It may help to save the planet (well, the planet will survive with our without humans--you know what I mean). That is a positive way in which demography might shape the destiny of human life on Earth.