Adapted from an article titled “Meeting the Sustainable Development Goals Leads to Lower Population Growth” by IIASA – International Institute for Applied System Analysis See http://pure.iiasa.ac.at/13348/1/WP%2016-007.pdf.
In September 2015 the leaders of the world under the umbrella of the United Nations in New York subscribed to an ambitious set of global development goals, the Sustainable Development Goals (SDGs) which unlike earlier goals give specific targets which apply to all countries of the world. If pursued, several of these targets, particularly in the fields of health and female education will have strong direct and indirect effects on future population trends mostly working in the direction of lower population growth.
An analysis by the International Institute for Applied Systems Analysis (IIASA) quantitatively illustrates that demography is not destiny and that policies – such as the recently agreed Sustainable Development Goals (SDGs), particularly in female education and reproductive health, can greatly contribute to reducing world population growth.
Based on a multi-dimensional model of population dynamics that stratifies national populations by age, sex and level of education with educational fertility and mortality differentials, we translate these goals into SDG population scenarios resulting in population sizes between 8 and 9 billion in 2100.
Today, the future of world population growth looks more uncertain than a decade ago, due to a controversial recent stall of fertility decline in a number of African countries and a controversy over how low fertility will fall below replacement level, particularly in China.
In 2008 projections by Lutz, Sanderson, et al. gave a 95% interval for the global population ranging from 5.2 to 12.7 billion in the year 2100.
In 2015 a different approach by the UN Population Division gave a much narrower 95% interval ranging from 9.5 to 13 billion in 2100.
Another recent set of world population projections defined in the context of the work of the IPCC (Intergovernmental Panel on Climate Change) showed in the medium scenario a peaking of world population around 2070 at 9.4 billion, followed by a decline to 9 billion by the end of the century with high and low scenarios reaching 12.8 and 7.1 billion respectively (Lutz et al. 2014; O’Neill et al. 2015).
In this paper the most relevant of these goals were translated into SDG population scenarios to quantify the likely effect of meeting these development goals on national population trajectories. This method shows the world population peaking around 2060 and reaching 8-9 billion by 2100, depending on the specific variant of the SDG scenario.
World population growth is sometimes called the elephant in the room due to its capability to cause environmental degradation as well as in making adaptation to already unavoidable environmental change more difficult (Ehrlich & Ehrlich 1990; O’Neill et al. 2001; The Royal Society 2012).
Population is widely perceived as a politically sensitive topic: the 1994 International Conference on Population and Development explicitly opposed the setting of “demographic targets” saying that the role of the state is 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.
There is increasing evidence that education, particularly in countries in demographic transition, has a direct causal effect on lowering desired family size and empowering women to actually realize these lower fertility goals with availability of reproductive health services also helping to enhance contraceptive prevalence. Universal primary and secondary education of all young women around the world is a prominent goal in its own right (SDG 4) and is politically unproblematic.
Lowering child mortality and decreasing adult mortality from many preventable causes of death are also politically unproblematic policy priorities. For child mortality the SDGs give precise numerical targets which could be directly translated into demographic trajectories and could be complemented through estimates of the indirect effects of better education of survival at all ages.
The population growth trajectories that would result from the successful implementation of the SDGs will come to lie far outside the 95% uncertainty range given by the 2015 UN probabilistic population projections.
The extrapolation model used by the UN gives all national fertility trends given equal weight, irrespective of whether they summarize the experience of just a few thousand couples or hundreds of millions of couples. In fertility, couples and not states are the relevant units of decision making and couples rather than countries should be given equal weight, which would greatly change the projection results.
The world community under the leadership of the UN launched an unprecedented global effort to strongly accelerate global efforts in development within the framework of the SDGs. Many of these goals, if reached, will have important effects in lowering future fertility and mortality rates, particularly in the least developed countries. Leaders of all countries and the entire UN system have committed themselves to do whatever it takes to reach the specified targets. This new global effort is a discontinuity of past trends and hence cannot be captured by statistical extrapolation of past trends.
Policies in the field of reproductive health and female education can have very significant longer term impacts on global population growth. Progress towards reaching the SDGs can result in accelerated strictly voluntary fertility declines that could result in a global peak population already around mid-century. These strong effects of the SDGs on lowering global population growth in a politically unproblematic and widely agreed way provides an additional rationale for vigorously pursuing the implementation of the SDGs.
See http://pure.iiasa.ac.at/13348/1/WP%2016-007.pdf for the full article.
Note: This article does list not the benefits of a lower population in any family, community or region. Smaller families means parents are more able to feed and care for their children. Fewer people mean fewer cattle to compete with wildlife over forage. Fewer people means less competition for livelihoods such as beadwork or bee keeping and less competition for jobs. Fewer people means governments are less likely to run out of funds for schools and road building.