A growing population can place stress on the environment, transportation, and the provision of natural resources like water, food, and energy in situations when governments fail to think strategically or are late to implement adequate adaptive reforms.
The ineffective management of natural resources can result in their scarcity and environmental damage, both of which are detrimental to initiatives aimed at encouraging sustainable development.
At the same time, if appropriate policies are adopted, an increasing population can also spur economic expansion and result in a larger labor force which is advantageous for sustainable development. And yet it is crucial to ensure that environmental conservation and the safeguarding of natural resources go hand in hand with economic progress.
Population growth forecasts
On November 15, 2022, the global population reached a milestone of 8 billion people. However, according to experts, this number is expected to increase even further.
Based on data from the United Nations, the global population will continue to grow over the next five to six decades, reaching its peak of around 10.3 billion somewhere around the mid-2080s.
After that, the number of people in the world will start to decline. By 2100, forecasts show that there will be around 10.2 billion people on Earth.
Today, according to experts, one in four people resides in a country where the population has already reached its peak.
Fertility rates and life expectancy
Fertility rates around the world are going down – in 2024, there were 2.3 births per woman registered, which is one child fewer compared to 1990.
As for life expectancy, this will continue to increase after hitting 73.3 in 2024 and is expected to reach 77.4 years by 2054.
Furthermore, by 2080, there will be more people aged 65 or older than the number of children aged below 18.
Low- and lower-middle-income nations will be the primary driver of population growth.
With some of the highest birth rates worldwide and declining mortality, Africa has seen an almost tenfold growth in its population.
Population growth forecast across continents (2024-2070)
Source: Our World in Data
The number of people in sub-Saharan African countries is predicted to climb by 79%, reaching 2.2 billion by 2054.
Africa’s current population is around 1.5 billion, and by 2100, it is predicted this will rise to 3.3 billion people.
Currently, Nigeria is the continent’s most populous nation with over 228 million residents, and by the end of the century, it could surpass the USA, which currently has a population of over 340 million.
The positive and negative effects of population growth on sustainable development
In a nutshell, global population growth can have both positive and negative effects. For instance, an expanding population can result in higher costs and potential obstacles to sustainable development but, at the same time, it can increase demand for goods and services which can boost economic growth.
The negative effects of growing population:
A growing number of people means more emissions, but at the same time, it also means economic growth and more innovation potential.
Let’s check out some of the worst impacts that a growing population can bring, and then analyze the benefits of this trend.
1. Climate change
Increasing consumption (especially in high-income nations) and the results of this contribute to an increasing level of greenhouse gas emissions, which trigger the warming of the atmosphere and, in consequence, a changing climate.
2. Environmental degradation
More people require more food, which means an increase in agricultural output. With outdated technology in agriculture this means deforestation to ensure more agricultural land is available. Logging and infrastructure development impact biodiversity and lead to more CO2 emissions.
Loss of habitat threatens ecosystem services by increasing the pace of species extinction.
In addition, overfishing damages ecosystems and reduces the number of marine fauna and flora species.
3. Resource shortage
Water scarcity worsens as demand exceeds supply, which is particularly visible in areas that are vulnerable to drought and poor regions that have outdated or absent infrastructure.
Food shortages intensify amid increased demand, the effects of climate change, and unsustainable farming practices.
5. Increase in municipal solid waste
The amount of municipal solid waste is expected to register an increase of nearly 100% from 2.1 billion tons per year in 2025 to 3.8 billion tons by 2050.
6. Higher pressure on urban infrastructure
More people within an urban region that has poorly planned infrastructure will result in traffic jams, degraded land, as well as issues with water, sanitation, and housing systems.
7. Pressure on social services and healthcare
Population growth exceeds economic capacity in low-income nations, placing a burden on the social safety net, healthcare system, and educational system.
The positive effects of growing population:
1. Larger workforce
More people could fill the void in industries that require a qualified workforce. If this is coupled with investments in education, health, and decent jobs, this can spur economic expansion, innovation, productivity, and entrepreneurship.
2. Innovation and economic growth
A larger market means more potential inventors and researchers, who can work on solutions for sustainability challenges (e.g., renewable energy, sustainable farming). This, in turn, will stimulate innovation and contribute to economic growth.
3. Diversity
An increasing population may bring together people from various racial, ethnic, and cultural origins, fostering greater diversity and a greater exchange of opinions.
4. Domestic market growth
Growing populations can potentially boost local economies and attract investment by increasing the domestic demand for products and services.
5. Better urban planning with increased sustainability
If properly controlled, rapid urbanization can lead to decreased per-capita emissions and better transport systems.
6. Potential for healthy aging economies
Healthy aging programs can keep older people in the workforce, generating social and economic benefits as they live longer lives.
The impact of upper-middle-income and high-income countries on sustainable development
Upper-middle-income and high-income nations tend to have lower rates of population growth and an extremely high amount of per capita resource use, including energy, water, and raw materials. This may put a strain on the world’s limited resources and harm other nations’ efforts to achieve sustainable development.
A growing population results in rising emissions and, combined with the industrial revolution and modern consumption patterns, these three issues are at the heart of the massive levels of CO2 and methane emissions that are causing climate change.
It is important to note, however, that the nations with most CO2 emissions at this point in time are not those with low average incomes and rapidly expanding populations, but rather those with high average incomes and populations that are currently growing gradually or not at all, or, to put this simply – wealthy nations.
CO2 emission by income level, 1980-2023 (in billion tons)
Source: Our World In Data
Since upper-middle-income and high-income nations rank among the major contributors to global warming, some low-income nations could face serious issues that are linked to sustainable development, and these countries are already at risk since most have limited adaptability and resilience to the effects of climate change.
Top 10 countries by CO2 emissions (2010 and 2023 comparison, million metric tons)
Source: Statista
Even though, as of 2023, China is the world’s biggest carbon dioxide polluter, the United States has historically emitted significantly more million metric tons of CO2 during its history (more than 400 GtCO₂ since 1750). China’s emissions have primarily been generated over the last 20 years, which accounts for the large difference between the two nations. China and the United States together have emitted nearly 40% of all CO₂ emissions since the Industrial Revolution in the late 18th century.
That is the total amount of emissions, but what if these were estimated per capita?
Top 10 countries by carbon dioxide emissions per capita
Based on data from the World Bank, the number one nation in terms of CO2 emissions per capita is Palau. With a population of 17,695 (as of 2024), the country tops the list mostly due to its two diesel-fired power stations.
The high per capita numbers are also a result of the use of private vehicles, boats, and airplanes which enable Palau’s many small islands to be explored.
Top-10 nations by Carbon dioxide (CO2) emissions per capita (t CO2e/capita)
Source: World Bank
*The combustion of fossil fuels is the primary cause of carbon dioxide emissions. The data in this graph covers fossil CO2 emissions from transportation, power generation, and heating, but does not include CO2 emissions that are linked with changes in land use (i.e., deforestation, reforestation).
*The graph also does not take into account emissions from international aviation and shipping, since these are considered in the global total.
*This data focuses on territorial emissions, which are emissions generated inside a nation’s boundaries rather than emissions from imported commodities.
Growing population leads to increased demand for resources
One of the consequences of population expansion is the rise in food demand which puts pressure on land, water, and energy. In addition, it leads to more chemical fertilizers and pesticides being used which ultimately leads to soil deterioration.
- In regions where people depend on subsistence farming (when farmers cultivate crops for their own consumption and that of their families), more land must be cleared for crops due to the lack or absence of irrigation, seed, and soil improvement. As a result, deforestation impacts biodiversity and soil health and affects the balance of carbon on the planet.
- Population growth and its impact on agriculture can also lead to habitat loss and can have a negative effect on biodiversity. Sustainable agricultural techniques can help to preserve biodiversity by using less hazardous chemicals and fostering ecosystem-supporting methods.
- As consumption patterns change, so do people’s diets. With a rise in average incomes, the change in the food that people eat has been shifting towards the consumption of more calories and a wider variety of resource-intensive foods (beef, dairy, poultry, pork, eggs).
Such changes have a detrimental effect on the environment causing a rising level of greenhouse gas emissions, a loss of biodiversity, and contamination of the water and soil due to poor environmental mitigation.
If governments want to put an end to hunger and deal with the problem of food insecurity, they could consider devising a comprehensive strategy that prioritizes boosting agricultural output through a sustainable approach, rather than an intensive strategy, and reducing food loss and waste, as well as improving the infrastructure and supply chains of food systems.
Growing population puts pressure on healthcare
Without a doubt, an increasing population puts pressure on healthcare and social care services, and several reasons back this claim:
- Overcrowding in healthcare facilities can result in longer queues, delayed care, and a shortage of medical staff.
- Communicable diseases spread more easily in dense populations.
- Overpopulation puts pressure on infrastructure, including waste management, clean water, and food supply.
Thus, population growth and diversification demand:
- Strategic planning, innovative care models, more personnel, better infrastructure, and investment in technology (which may put financial strain on providers and governments).
- A greater need for specialized services (such as mental health, long-term care, and care for the elderly).
- Flexibility of healthcare systems to meet changing needs to guarantee fair access and high-quality treatment.
Growing population and reproductive health
Ensuring that women have the freedom to choose when and how many children to have can significantly boost well-being and help to break cycles of poverty among generations.
According to the UN, if more people have access to excellent reproductive health services, this could help to manage fertility rates and accelerate social and economic growth. This mainly concerns lower-income countries.
Reproductive health is also in line with a number of the Sustainable Development Goals (SDGs), notably SDG 3 on health and well-being, SDG 5 on gender equality, and SDG 17 on partnerships for the goals.
Final word
The continuously growing population could lead to the depletion of natural resources, environmental degradation, and overcrowding. It is evident that if everyone continues to consume at levels comparable to those of today’s developed nations, with the technologies available today, the world will be unable to sustainably maintain the existing population. At the same time, however, population growth can increase economic growth and technological innovation.
Considering the positive and negative outcomes, maintaining the balance between population growth and sustainable development calls for careful planning, investment in sustainable technology, and international cooperation.
