KEY FORESIGHT AND PREPAREDNESS FUNCTIONS IN THIS CHAPTER
CONTEXT AND CHALLENGES
To prepare for the future, it is essential for policy makers to understand the current demographic situation and how it may change in the next 5, 10 or 15 years and beyond. With appropriate planning, least developed countries could reap a “demographic dividend,” consisting of faster economic growth per capita thanks to a working-age population that is growing in size relative to the population of children and older persons. However, as the population distribution continues shifting towards older ages, financial pressures rise due to the high costs of providing pensions and especially health care for the burgeoning older population.
Urban population increase, driven in part by migration flows from rural to urban areas, is helping to make cities the engine of growth in developing countries. Meanwhile, it is expected that international migration will be the main driver of population growth in high-income countries over the next few decades. And while the issue of migration remains politically sensitive, there is greater recognition that migrants make a positive contribution to inclusive growth and sustainable development in countries of origin and destination.
The need for reliable population data has increased in the wake of the COVID-19 pandemic. With rising uncertainty around future trends amidst multiple global crises, reliable and timely data and internationally coordinated action are needed now more than ever to set the world back on track, to build resilience, and to make sustainable choices that can benefit both people and the planet.
FORESIGHT AND PREPAREDNESS FUNCTIONS
1.
Delivering robust population foresight
UN DESA produces comprehensive and internationally comparable population data and analysis to inform future-oriented policy making. The Department provides global population estimates and projections, including fertility and mortality rates, disaggregated by age and sex and looking ahead as far as 2100. World Population Prospects 2024, the twenty-eighth edition of the United Nations estimates and projections of global population, concluded that the global population would reach 8.2 billion people in 2024, 8.5 billion in 2030, 9.6 billion in 2050 and 10.2 billion in 2100, according to the “medium” projection scenario and taking into account the impact of the pandemic on all three components of population change (fertility, mortality and international migration). The dataset also provides 80 and 95 per cent prediction intervals, which illustrate the increasing uncertainty of these projections as a function of time (figure 1). It includes 12 additional scenarios to illustrate the sensitivity of the projections to changes in the underlying assumptions.
Figure 1.
World population, estimates, 1950–2023, and projections (medium scenario), 2024–2100, with 95 per cent prediction intervals.
Source: World Population Prospects 2024.
NOTES: Prediction intervals represented by coloured lines around central projection; for a given year, the future trend is expected to lie in the predicted range with a probability of 95 per cent.
Collaboration with the UN system on mortality indicators
The Department promotes coordination across national statistical systems and produces estimates of mortality and life expectancy at the global, regional and national levels. WHO provides a breakdown of total mortality in terms of causes of death. Similarly, the Statistics Division of UN DESA has worked with WHO to encourage closer cooperation between health ministries and national statistical offices and to support the development of comprehensive international standards for the regular production of complete and reliable vital statistics. A technical advisory group convened by WHO and UN DESA and comprising over 30 global experts provided expertise and technical resources to support estimation of the excess mortality associated with the COVID-19 pandemic (figure 2). UN DESA also collaborates on estimation of child mortality and maternal mortality indicators with partners including UNICEF, WHO, the World Bank and UNFPA.
Figure 2.
Global life expectancy at birth (as observed) and counterfactual scenario without COVID-19 excess mortality, 2010-2023.
Source: World Population Prospects 2024.
UN DESA provides reliable estimates and projections of trends in fertility rates and patterns of marriage and union formation and dissolution for all countries of the world. Fertility levels and trends are a key predictor of population growth or decline and the principal determinant of changes in the population age distribution. In the World Population Prospects advanced statistical methods are used to project fertility trends (figure 3). The Department’s work on fertility extends beyond the reproductive behaviour of individuals and provides insights into wider social and economic changes such as increases in women’s educational attainment and labour force participation.
Figure 3.
Global total fertility rate (live births per woman), estimates, 1950-2023, and projections (medium scenario), 2024--2050, with 95 per cent prediction intervals.
Source: World Population Prospects 2024.
NOTES: Prediction intervals represented by coloured lines around central projection; for a given year, the future trend is expected to lie in the predicted range with a probability of 95 per cent.
Data on early childbearing
Early childbearing affects social and economic outcomes for girls, women and their families, while complications from pregnancy and childbirth are the leading cause of death among adolescent girls. The Population Division of UN DESA is the custodian agency of SDG indicator 3.7.2, the adolescent birth rate for ages 10-14 and 15-19 years, which is used for the global monitoring of progress towards achieving SDG target 3.7 on ensuring universal access to sexual and reproductive health-care services. Every two years, the Division updates a global data set that includes information for over 200 countries and areas on birth rates among women aged 15-19 years and, since 2022, also for girls aged 10-14 years. Estimates and projections of adolescent birth rates at the global, regional and national levels are available from the World Population Prospects, providing information on the progress made in reducing early childbearing (see Figure 4). In the 2024 edition, the World Population Prospects included, together with the projections of adolescent birth rates based on historical trends, three additional scenarios of an accelerated reduction of adolescent birth rates, showing the impact on future numbers of births and population growth.
Figure 4.
Adolescent birth rates, world and SDG regions, 1994 and 2024.
Source: World Population Prospects 2024.
The most recent edition of the World Population Policies in 2021 draws attention to the fact that population growth driven by high fertility remains a concern for some countries, while others are faced with population ageing and, in extreme cases, population decline driven by low fertility. The report also provides a review of trends in global fertility levels from the early 1960s and details the evolution of national fertility policies – thus providing an important historical record as well as lessons for future policy making. Since 2020, reports assess the impact of the COVID-19 pandemic on fertility patterns and trends and offer policy options for governments to consider strengthening sexual and reproductive health care and services.
UN DESA’s tools and analytics deliver trusted resources on family planning. Publications and data sets on family planning produced with support from the Making Family Planning Count initiative bring methodological and technical rigour to improving the availability and quality of key family planning indicators and related population data. The Programme of Action of the International Conference on Population and Development affirmed the basic right of couples and individuals to decide freely and responsibly the number and spacing of their children and to have the information, education and means to do so. Global data sets and analyses of contraceptive use and family planning fill critical data gaps, providing information to help governments and other stakeholders with the design, implementation and monitoring of national health and family planning policies and programmes and with assessing progress towards the national and global commitments of the Programme of Action and the SDGs. A comprehensive data set of key family planning indicators, World Contraceptive Use, contains empirical data on the prevalence of contraceptive use and on the unmet need for family planning among women of reproductive age (15-49 years), drawn from more than 1,600 surveys. Such data are used to generate annual estimates and projections of family planning indicators from 1970 to 2030, published biennially as Estimates and Projections of Family Planning Indicators, and for the global monitoring of SDG indicator 3.7.1 and of the family planning component of SDG indicator 3.8.1 on universal health coverage.
The report World Family Planning 2022 presents the latest information about family planning at the global, regional and national levels. The report assesses levels and trends in contraceptive use and the demand for family planning among women of reproductive age between 1990 and 2021, including the proportion of women of reproductive age (aged 15-49 years) who have their need for family planning satisfied with modern methods of contraception (SDG indicator 3.7.1). The report also presents trends in contraceptive use by type of method, including regional variations in the use of specific methods, and examines how contraceptive use and needs vary by age, highlighting gaps in meeting the need for family planning among adolescents and young women.
2.
Helping Member States to anticipate trends in urbanization and migration
The Department prepares estimates and projections of the size of the urban population at the global, regional and national levels. According to World Urbanization Prospects 2018, by 2050 more than two thirds of the global population may be living in cities (figure 5). Urban population growth, driven in part by migration from rural to urban areas, will increase pressure on cities to provide basic services for their residents and will increase their exposure and vulnerability to natural disasters and climate change. Achievement of the SDGs requires the effective management of urban growth and the creation of sustainable cities in both developed and developing countries.
As global levels of migration intensify, UN DESA’s publications and data sets capture credible data at scale, deepen understanding on the plight of people on the move, share lessons, and offer policy recommendations. The International Migrant Stock dataset provides disaggregated estimates on the number (or “stock”) of international migrants at global, regional and national levels. It includes information for 232 countries and areas, obtained primarily from national population censuses. The dataset provides the latest estimates of the number of international migrants by age, sex, country of origin and country of destination. The latest report on the topic, International Migration 2020 Highlights, shows how the pandemic impacted millions of migrants and undermined progress on the SDGs. These products are useful not only for analytical purposes but also to raise awareness about various issues, including the challenges of comparing statistics across countries due to differences in concepts and definitions.
Figure 5.
Proportion urban, world and regions, 1950-2050.
Source: World Urbanization Prospects 2018.
