Fisher on a small boat in Semporna, Sabah, Malaysia

Population and Climate Change

Climate change is humanity’s most critical challenge, and the risks are multiplying. By burning fossil fuels and deforesting vast areas, humans have increased concentrations of greenhouse gases in the atmosphere to levels unprecedented in at least 800,000 years. As a result, the Earth’s average temperature is rising, endangering food security, the availability of fresh water, and human health. Demographic trends play an important role in understanding and confronting the world’s climate crisis.

Regardless of future emissions trends, the warming that has already resulted from the pre-industrial period to the present will continue for hundreds to thousands of years. These changes will continue to impact people in many ways, but specifically in terms of our capacity to use and manage land, adapt to extreme weather events, produce food, and access vital resources like fresh water. Limiting the global temperature rise is imperative to humanity’s survival.

Preventing further climate change requires ending the burning of fossil fuels for energy, industry, and transportation. This is especially imperative for high consuming regions such as Northern America, Europe, Australia, and China. Stopping forest loss, planting new forests, and managing land to conserve soil carbon are additional important steps to limiting warming that both industrialized and developing countries must prioritize.


People living in the United States, Australia, and Canada have carbon footprints almost 200 times larger than people in some of the poorest and fastest-growing countries in sub-Saharan Africa—such as Chad, Niger, and the Central African Republic.


Just 10 countries account for over two-thirds of current annual energy-related greenhouse gas emissions.

According to the UN, the world’s 47 least developed countries are the fastest growing and will continue to experience rapid population growth between 2019 and 2050. Nine out of the ten most climate vulnerable countries are in sub-Saharan Africa, which is expected to double in population by 2050—accounting for half the world’s population growth.

Traffic in Masina, Kinshasa, Democratic Republic of the Congo

Climate change is closely linked to population growth. In high-income countries especially, population growth directly causes climate change because each additional person causes significant emissions throughout their lifetime. High consuming lifestyles in the most affluent countries result in much higher per capita emissions than in middle- and low-income countries, where most of the world’s population lives and is projected to grow. In contrast, people living in low-income regions contribute very little to overall emissions but are disproportionately vulnerable to the weather extremes, water stresses, and food production challenges associated with a warming climate. In the center of the spectrum are middle-income countries, home to 75% of the world’s population. In these places, industrialization will increase consumption over the coming decades. Without changes to how economies tend to grow, carbon emissions will rise. One of the many unjust realities of the climate crisis is the unevenness of development trajectories across the world: The very processes of industrialization that have historically facilitated increases in living standards, overall health, and economic growth for affluent nations now also act as environmental threats for which consequences are more immediate and life-threatening than ever before.

Many of the world’s floodplains and coastlines are densely populated. Low-elevation coastal zones represent 2% of the world’s land area but contain well over 10% of the world’s population. Of the world’s 31 megacities (a city with a population above 10 million), 21 are along a coastline, and migration to the coasts is increasing. The World Resources Institute projects that the number of people affected by flooding will double between 2010 and 2030.

Aerial view of densely populated shoreline, Belas, Angola. Photo by Hermenegildo Sebastião on Unsplash


The UN’s medium variant projection shows that the global population will likely grow to 8.5 billion in 2030, 9.7 billion in 2050, and 10.4 billion in the 2080s. The fastest growth occurs among the 46 Least Developed Countries (LDCs). In these regions especially, rapid population growth exacerbates climate vulnerability and puts more people at risk.


Nine out of the ten most climate vulnerable countries are in sub-Saharan Africa, which is expected to double in population by 2050—accounting for half the world’s population growth. People in Somalia, Burundi, and the Democratic Republic of the Congo are among those facing frequent droughts, severe floods, extreme heat, and soil erosion, amidst rapidly growing populations. 

Currently, almost 1.8 billion people across 17 countries—a quarter of the world’s population—live in regions of extremely high water stress. Of these countries, 11 are located in the Middle East and North Africa, where annual average population growth of 1.7% is higher than the global average of 1.1%. Population pressures increase the threats posed by the decreasing availability of fresh water.

Aerial view of people surrounding water well in rural India

Population pressures compound the negative effects of climate change. Both population growth and climate change contribute to resource depletion, economic insecurity, and decreased overall health. Growing populations increase demand for these diminished natural resources, furthering environmental degradation and posing challenges for equitable resource allocation. Additionally, population pressures undermine food security, poverty alleviation, access to education, the status of women, and climate adaptation.

As there is no panacea for combating climate change, a wide variety of options needs to be exercised. An integrated approach includes educating girls and empowering women to make their own childbearing decisions.

Worldwide, many of the same regions that experience high fertility, low economic status, and high climate vulnerability also have a high unmet need for contraceptives and reproductive health services. Recent research from Project Drawdown shows that family planning, together with girls’ education, could prevent emissions of 85 gigatons of CO2 equivalent by 2050—equivalent to what could be achieved by shutting down 22,000 coal-fired power plants.

Investing in family planning is an extremely cost-effective climate change solution—both in terms of upfront cost and return on investment. The emissions averted through investments in family planning are also much cheaper (about $4.50 per ton of CO2) in comparison to other options such as solar power ($28 per ton) or carbon capture and storage.

Picture of different contraceptive methods: birth control pills, an injection syringe and condom, IUD. Adobe Photos

There is currently a $5.3 billion funding gap for meeting family planning needs worldwide; yet, family planning programs receive less than one percent of international development aid. Increasing spending to fill the unmet need for family planning services will help address a variety of global challenges, ranging from development and human rights to climate change mitigation and adaptation. Healthy and educated populations are also better equipped to weather the effects of climate change.

African Mother And Two Children Walk Alone In Red Clay Road In Village As A Family

Relevant SDG Targets

Strengthen resilience and adaptive capacity to climate-related hazards and natural disasters in all countries

Integrate climate change measures into national policies, strategies and planning

Improve education, awareness-raising and human and institutional capacity on climate change mitigation, adaptation, impact reduction and early warning

Implement the commitment undertaken by developed-country parties to the United Nations Framework Convention on Climate Change to a goal of mobilizing jointly $100 billion annually by 2020 from all sources to address the needs of developing countries in the context of meaningful mitigation actions and transparency on implementation and fully operationalize the Green Climate Fund through its capitalization as soon as possible

Promote mechanisms for raising capacity for effective climate change-related planning and management in least developed countries and small island developing States, including focusing on women, youth and local and marginalized communities

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Climate Change Info Brief

Demographic trends and variables play an important role in understanding and confronting the world’s climate crisis. This resource provides a comprehensive analysis of the ways in which population growth and dynamics intersect with climate change. The brief concludes by arguing that efforts to address climate change must include increasing access to reproductive health care services, education, and voluntary family planning options.

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Climate Change Slide Deck

This presentation explores the connections between population dynamics, access to comprehensive health care, and climate change. Through an historical examination of global population dynamics, the slide deck will help clarify the links between poverty, marginalization, women’s rights, and environmental pressures made worse by climate change. The presentation concludes by showing how access to family planning and reproductive health care services is critical to women’s empowerment and can play an impactful role in climate adaptation and mitigation efforts.

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Recommended Readings

Browse literature on population growth and climate change. This resource provides academic sources, research published by NGOs and government agencies, and relevant news articles—perfect for curating a course reading list for college students.

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