Focus on Demographic Pressure.

 

The ETR demographic pressure indicator is based on projected population increases between 2025 and 2050. It is a forwardlooking measure that aims to capture the ways in which rapid population growth could exacerbate existing stresses in social and natural environments. Population growth has been strongly linked to environmental degradation, particularly in areas that are already overpopulated and suffering from stretched natural resources. Of the 3,125 subnational areas assessed in the 2025 ETR, 304 have very high levels of demographic pressure, with population growth projected to exceed 50 per cent in the next 25 years. A further 337 subnational areas are facing high demographic pressure, with projected growth of around one-third. The total population in these two categories is projected to increase by more than 646 million, representing over half of the world’s population projected increase by 2050, despite comprising only around 15 per cent of the global population in 2025. As shown in Figure 1.19, demographic pressures are most concentrated in sub-Saharan Africa and the Middle East and North Africa, where populations are projected to grow by 49 and 28 per cent respectively by 2050. The ten countries projected to record the fastest population growth will collectively add more than 339 million people, accounting for over a quarter of global population growth between 2025 and 2050. 

As Table 1.6 highlights, eight of these ten countries are in sub-Saharan Africa, led by Niger, Uganda, and Malawi, where populations are expected to nearly double. This rapid expansion will intensify stress on food systems, water resources, and infrastructure in regions already facing high ecological and social vulnerabilities.

At the same time, population dynamics are diverging in other parts of the world. The Asia–Pacific region is projected to contract by 2.7 per cent by 2050, largely due to an eight  decline in China’s population, equivalent to more than 114 million people. Japan and Taiwan are also projected to shrink by 11 and nine per cent respectively. In Eastern Europe and Central Asia, several states are projected to experience some of the steepest contractions worldwide, including Moldova, Georgia, and Lithuania. Collectively, the ten countries projected to see the largest declines will lose more than 20 million people by midcentury, with seven of them located in this region. In general, lower population pressure reduces competition for finite resources such as food, water, and land. With fewer mouths to feed, global food demand would decline over time, potentially shrinking the farmland area required. This would in turn ease pressure on rivers and aquifers, helping to stabilise groundwater levels and curb over-extraction. While slowing or negative growth may ease direct pressure on ecological resources, it brings new challenges. Ageing societies will face shrinking labour forces, rising old-age dependency ratios, and mounting demands on health care, pensions, and other public services. By the 2050s, older adults will far outnumber children, reversing a demographic balance that has persisted for centuries. This transition risks constraining economic growth and fiscal capacity, making it harder to finance adaptation and resilience measures at the very moment when ecological threats are intensifying. Demographic pressure, therefore, is not only about growth in fragile regions but also about the vulnerabilities created by decline and ageing in wealthier ones.

The United Nations publishes its World Population Prospects report biennially, providing demographic estimates from 1950 to 2100. The most recent edition, released in 2024, projects that the global population will peak at nearly 10.3 billion in 2084 before declining slightly to around 10.2 billion by 2100.46 The report also forecasts that the global fertility rate will fall below the replacement rate of 2.1 births per woman by 2050, the threshold required for each generation to replace itself. As shown in Figure 1.20, UN projections of future population size have been revised downward over the past decade, driven largely by faster-than-expected declines in fertility rates, particularly amongst many Asian and European countries. Falling fertility has substantially reduced the annual rate of global population growth, which peaked in 1963 at around 2.3 per cent and has since declined to an estimated 0.8 per cent in 2024. Growth is projected to turn negative in 2085, with the global population expected to contract by around 0.13 per cent annually by the end of the century.

The number of people aged over 60 is projected to keep rising throughout the century, eventually surpassing three billion people. During much of the 20th century, children under five outnumbered adults over 60, but this trend reversed in 2002, as shown in Figure 1.21. Global life expectancy is currently estimated at around 73 years but is projected to rise substantially in the coming decades. By contrast, the population of children under five peaked in 2017 at around 698 million and is expected to decline by nearly 27% by the end of the century. This inversion of the age pyramid will create new vulnerabilities. Labour shortages may undermine productivity, while pension and health systems face unprecedented strain. At the same time, fiscal space for climate adaptation and resilience could narrow. While sub-Saharan Africa and South Asia contend with the pressures of rapid population growth, wealthier regions must manage the fragilities of shrinking and ageing populations – two divergent trends that together highlight why demographic change is central to future ecological and social stability.