Eight reasons to be concerned about our population reaching 8 billion

Our population has reached a major milestone today: 8 billion people. While many may see this as an occasion to celebrate, our large and growing population presents some serious challenges.

The latest projections by the United Nations Population Division revealed that our numbers will continue to rise until well into the second half of this century, crossing the 8.5 billion mark in 2030, hitting 9.7 billion in 2050, and peaking around 10.4 billion people in the 2080s, with no further change before 2100.

On this year’s World Population Day (July 11), UN Secretary-General António Guterres noted that reaching 8 billion “is an occasion to celebrate our diversity, recognize our common humanity, and marvel at advancements in health that have extended lifespans and dramatically reduced maternal and child mortality rates.”

We should indeed take a moment to reflect on the amazing progress that has made this astounding population size possible. However, we cannot shy away from its serious implications for the environment, sustainable development, and humanity’s future on this planet.

The United Nations Population Fund (UNFPA) was set up in 1969 to address rapid population growth, which was recognized at the time as a major hindrance to countries’ development and poverty alleviation. In light of these origins, it was somewhat surprising that UNFPA’s current Executive Director, Natalia Kanem, recently told The Guardian,

“Some express concerns that our world is overpopulated, with far too many people and insufficient resources to sustain their lives. I am here to say clearly that the sheer number of human lives is not a cause for fear.”

Citing historical human rights abuses in the name of population control, she stated that “population alarmism” risks a repeat of these violations and “distracts us from what we should be focused on.”

UNFPA’s webpage to commemorate the milestone reinforces this message and paints a (literally) rose-tinted picture of “A world of 8 billion possibilities,” claiming overpopulation concerns are unfounded and that the planet can sustain this many humans.

There is never any justification for coercion, and UNFPA’s focus on empowering women to choose their family size is absolutely right. This does not mean, however, that we should turn a blind eye to the wider social and environmental implications of population growth. Fortunately, the UN Department of Economic and Social Affairs (DESA) took a more factual approach and addressed some of these implications in its policy brief. Here are eight important reasons we should be concerned about sailing past 8 billion.

1) Rapid population growth indicates extreme gender inequality

One major reason not to celebrate our continued population growth is that it reflects much too slow progress on women’s rights. The areas with the highest fertility rates (the average number of births per woman) are those where girls and women lack access to education, career opportunities, and bodily autonomy. Wherever women have the power to decide what happens to their bodies and lives, and are free to choose their family size, fertility rates have plummeted below the replacement level of 2.1 births per woman.

2) More humans, less nature

Human population growth is a key driver of biodiversity loss, a widely neglected crisis that is still accelerating. A major 2019 UN report found that one million species are now threatened with extinction, and only one quarter of all land and one third of marine areas remain relatively undisturbed by human activities.

The WWF’s latest Living Planet Report shows that vertebrate wildlife populations declined by an average of 69% between 1970 and 2018. During that time, the human population doubled. Biodiversity loss and ensuing ecosystem collapse are tragic in their own right, but they also pose a huge threat to food and water security, public health, and resilience to climate change impacts.

3) Climate targets moving out of reach

Unsustainable burning of fossil fuels in wealthy nations is largely responsible for the climate crisis, but global population growth is an important driver of rising emissions, especially in light of growing incomes and consumption in emerging economies thanks to poverty alleviation.

Research by Project Drawdown found that slowing population growth by removing barriers to family planning and education represents the third most powerful available climate solution to limit warming to 2°C, after reducing food waste and switching to plant-rich diets.

Limiting climate warming to 1.5 or 2°C as laid out in the Paris Agreement will become ever harder with ever more consumers striving towards a comfortable life and requiring the conversion of more natural carbon sinks to cropland and urban infrastructure.

4) More lives and livelihoods at risk

The fastest population growth is occurring in some of the areas facing the worst impacts of the climate crisis — this phenomenon of more people and infrastructure moving into harm’s way is known as the “expanding bullseye” effect.

Disasters such as floods, storms, droughts, and wildfires are increasing in severity and frequency and will destroy more and more lives and livelihoods without ambitious action to limit emissions and population growth. Almost a quarter of the global population is already at risk of severe flooding.

5) Worsening resource scarcity

The combination of climate change and population growth is also a major threat to natural resources, as well as food and water supplies. We are collectively already using resources 1.8 times faster than they can regenerate, meaning we would need two planets to sustain the demands of our current population without destroying nature.

Areas that are hard-hit by both climate change and population growth, like the Sahel region of Africa, are also struggling with high poverty rates, which creates a recipe for disaster. After decades of hard-won progress in alleviating hunger and malnutrition, they are on the rise again. An estimated 768 million people were affected by hunger in 2021, an increase of 150 million since 2019.

Thirty-eight percent of the global population (more than 3 billion people) live in a country where domestic food production is less than what the population consumes, and with a lower-than-global-average income per person. This creates a high risk of food insecurity, especially as populations continue to grow. Human demand for water has increased six-fold over the past century and is still rising by around 1% per year, while a third of the global population lives in water-stressed countries.

6) Increasing conflict

Worsening water shortage is leading to escalating conflict in drought-stricken areas, including the Sahel. Deadly violence over access to water has created a flood of refugees from some countries, such as Cameroon. Rapid population growth also creates a ‘youth bulge,’ which can lead to civil unrest and religious or political extremism in developing countries with insufficient infrastructure and public services to provide young people with education and incomes.

According to the new UN projections, half of the projected increase in the global population up to 2050 will be concentrated in just eight countries, none of which are well-equipped to handle this dramatic expansion: the Democratic Republic of the Congo, Egypt, Ethiopia, India, Nigeria, Pakistan, the Philippines, and Tanzania.

7) Public health implications

A more crowded world increases the risk of disease transmission and the emergence of new viruses with pandemic potential. All recent pandemics, including SARS, Ebola, bird and swine flu, and most likely Covid-19, were zoonotic, meaning the pathogen originated in an animal and was then transmitted to a human host, often via an intermediate livestock host. A 2020 UN report stated,

“The underlying causes of pandemics are the same global environmental changes that drive biodiversity loss and climate change. These include land-use change, agricultural expansion and intensification, and wildlife trade and consumption.”

All of these drivers are amplified by human population growth. Population growth is also correlated with increasing air, water, and noise pollution. According to the World Health Organization (WHO), polluted air causes 7 million premature deaths every year. Overreliance on dirty fuels is a major source of air pollution, but the number of consumers matters too — some of the most densely populated areas, including South Asia, are the worst affected. Additionally, many studies have found that high population density is associated with worse mental health.

8) Population action key to meeting the SDGs

The UN’s 17 Sustainable Development Goals (SDGs) aim to achieve a good quality of life for all on a healthy planet, yet we are far off track to meeting them by their 2030 deadline, with many progress indicators worsening instead of improving. As noted by UN DESA,

“Rapid growth poses various challenges to the achievement of SDGs related to schooling, public health, housing, water and sanitation, employment and poverty. Rapidly growing numbers of children and youth in low-income countries can hamper progress towards ensuring inclusive and equitable education and healthy lives and well-being for all.”

Continued population growth is also incompatible with achieving the environmental SDGs, including ending climate change and biodiversity loss on land and in seas. Without drawing the links between population growth and environmental and development crises, it is unfortunately hard to increase adoption of policies aimed at empowering women and improving access to family planning and education. For example, the advancement of reproductive rights is unlikely to be included in countries’ climate budgets if influential groups deny that this is a climate mitigation measure.

We need to be concerned about our large and growing population. Refusal to acknowledge the critical interconnections between environmental and social challenges will hold back progress and much-needed funding.