Diverging global population trends (GMT 1)

Changing age structures

Declining fertility levels, coupled with gains in life expectancy, are increasing the world's median age, which is expected to increase from 28 to 36 between 2010 and 2050, and raise the percentage of over 65s from 8–16 % of the global population by 2050.^[2]

Contrary to the aging population of developed regions, some developing-world countries are or will soon experience substantial youth bulges (Figures 2, 3). Providing educational and employment opportunities for these young people will be challenging, but critical if political and social stability is to be ensured.^[11]

Figure 2: Share of population under age 20 and over age 65 by regions in 2010, 2030 and 2050^[2]
 

Source: UN World population prospects: The 2012 revision

Shifting migration patterns

Since the 1960s, there has been a trend of migration from less developed to more developed regions. In 2010, however, the growth rate of the international migrant stock in developing countries surpassed that of developed countries for the first time. Several countries in developing regions (e.g. Kuwait, South Africa and Thailand) have been attracting significant numbers of migrants, including refugees from neighbouring countries.^[12] China, India and South America could attract more migrants as growth in their working-age population slows and wages rise.^[11]

Although economic and social motives are still key drivers for migration, environmental degradation and climate-change impacts are becoming increasingly important due to increased exposure to natural hazards and the corresponding threats to livelihoods.^[13][14] In some instances, however, climate change impacts and environmental degradation can actually deter migration if communities lack the resources to meet the costs of relocating.^[14] Due to the high degree of complexity and uncertainty in calculations, projections for climate change-induced migration by 2050 vary from 25 million people to one billion people.^[15]

Implications

Environmental pressure

UNEP assesses population growth and patterns of production and consumption as the main drivers of environmental and land-use change. Population growth and related economic development boost humanity's use of and competition for non-renewable resources while escalating the consumption of biotic resources, the production of harmful emissions and waste, and the disruption or destruction of natural habitats (GMTs 8, 10). Environmental damage may become particularly significant in sub‑Saharan Africa and parts of south-east Asia, where high population growth rates coincide with a direct dependency on natural capital – forests, fisheries, freshwater etc.^[15][16]

In the longer term, changing patterns of consumption, in part driven by the development of a growing, increasingly affluent middle class in developing regions (GMTs 2, 5) are likely to boost unsustainable practices that erode essential and irreplaceable natural resources and increase pollution, processes which will undermine the very basis for economic growth and social progress.^[17] 

Economic impacts of expanding work-forces

Population trends directly influence economic activity, shaping the size and age structure of working populations (Figure 3). In many countries, strong growth in the working-age population, alongside improvements in health and education, and investment in infrastructure and technology, have contributed to rapid economic growth.^[11][18] The share of the population with secondary and tertiary education is projected to increase everywhere by 2050, particularly in Asia and Africa, potentially boosting further economic growth (Figure 3). China, for example, is expected to have more educated people of working age than Europe and North America combined by 2030.^[19][20] This trend is already apparent. While advanced economies dominated growth during the 20th century, emerging economies are rapidly gaining prominence, partly by providing a production centre for developed economies. Brazil, Russia, India, Indonesia, China and South Africa (BRIICS) accounted for 21 % of global output in 2000, 32 % in 2010 and, according to projections, their economic production will exceed the GDP of OECD members by around 2030, and will account for 56 % of global GDP by 2050.^[19]

Social cohesion

The world reached a peak in its share of 15–24 year-olds around 1985, but in the least-developed countries it only occurred in 2005 and the proportion of young people will remain high in the coming decades with the largest youth bulges likely in sub-Saharan Africa and the Middle East (Figure 2). Failing to create employment opportunities for young people is both a waste of human resources and a source of potential conflict.^[11]

Policies supporting an increase in choices and opportunities, including the provision of contraceptive services, can support desirable population trends and mitigate negative effects in the future.^[7] In developed countries, social cohesion is more likely to be threatened by an aging population and population decline (Figures 1, 2, 3). These may alleviate some of the demands on ecosystems, and the right policies could ensure that the growing number of older but active people provide an economic dividend.^[4] Nevertheless, an aging population can threaten social security, taxation, and public health systems. Policy-makers will have to make difficult trade-offs, some of which can be mitigated by early action on structural reforms.^[19]

Immigration may alleviate some of these pressures by putting more people of working-age, often with higher education, into employment. It is estimated, for example, that 30 % of migrants in the OECD have tertiary education.^[21] In developing regions, however, the emigration of highly skilled people is a major concern; for example one in nine tertiary-educated people born in Africa now resides in OECD countries.^[21] Migration of young workers can, nonetheless, deliver economic benefits to their native countries; the World Bank estimates that remittance flows to developing countries in 2013 were nearly three times the size of official development assistance and will increase.^[22]

Implications for Europe

Europe's population is aging rapidly (Figure 2), and is likely to stagnate – significant increases in some Member States balancing declines in others. This may ease, though not curb, environmental pressures, but much depends on environmental policies to address such issues as urban sprawl and production and consumption habits. One environmental concern is the decline of household size, which has accelerated since 1900.^[23]

Furthermore, likely demographic trends will create other challenges – an expanded workforce during recent decades has underpinned improvements in living standards and the development of the welfare state. Sustaining these may be difficult in the light of population dynamics.^[4] EU Member States may be able to pre-empt some challenges, for example through integrated urban management or effective support structures for older populations. Nonetheless, keeping the global nature of environmental issues in mind, Europe should persist, both through its own policies and engagement in international dialogue on environmental issues, with efforts to decouple natural resource use and the production of pollution from economic development in the move towards a green economy.^[4]