In today’s demographically diverse world, population issues abound, creating different and important social, economic, and political implications. World Population Day (observed each year on July 11) offers an opportunity to reflect on why population is so important. Understanding the implications of population growth and decline, as well as population age structure and migration—is essential to strengthen our abilities to plan for a more sustainable future.

Growing vulnerability from climate change adds even greater urgency to the challenges posed by these looming population issues. In a new report, Population Growth and Climate Change Vulnerability: Understanding Current Trends to Enhance Rights and Resilience, the Population Institute asked researchers to analyze population and other indicators in the 80 most climate-vulnerable nations, as rated by the Notre Dame Global Adaptation Initiative (ND-GAIN). They found that the average population growth rate in the most vulnerable countries is double the global rate, and concluded that such growth also has important—yet often overlooked—implications for climate change adaptation and resilience.

Tracking Intersections of Growth and Vulnerability

Any discussion of the challenges that come with a warming world demands that we acknowledge two key points. The first is that human-induced climate change has been driven by disproportionate consumption patterns in the Global North. The other is that the countries most vulnerable to the impacts of climate change—most of which are in the Global South—bear little responsibility for creating the current climate crisis.

Action to address climate change requires political commitment and significant investment from countries in the Global North to shift their patterns of production and consumption. It also demands robust support for a clean energy transition and resilience in countries that are most vulnerable.

Population trends intersect in important ways with these multiple dimensions of vulnerability. The ratings provided by ND-GAIN measure a country’s vulnerability to climate change through the collection of data that encompasses their exposure, sensitivity, and adaptive capacity to these trends—all of which are affected by population growth.

Assessing exposure helps us understand the extent and severity of projected physical factors such as freshwater availability and sea level rise. At the most fundamental level, a growing population means that the number of people exposed to such impacts will increase over time.

Sensitivity reflects the degree to which people and the sectors they depend upon are affected by climate perturbations. For example, in many of the most vulnerable countries, large majorities of the population work in agriculture, and many households’ food security is linked to small-holder farming, much of which is rain-fed.

Food security already poses a significant challenge for vulnerable countries. In the 80 countries assessed in the report, the average proportion of the population experiencing severe food insecurity is 20 percent. Population growth will further challenge efforts to effectively address hunger, water scarcity, and other challenges that are directly tied to climate-sensitive sectors.

Lastly, tracking a country’s adaptive capacity measures the ability of society and its supporting sectors to adjust to reduce potential damage and respond to the negative consequences of climate events. The ND-GAIN rankings incorporate multiple indicators to measure adaptive capacity, including access to improved sanitation, electricity access, and disaster preparedness. Under conditions of rapid population growth, governments will be further strained in their ability to provide basic services that are already insufficient in many of the most vulnerable countries.

Gender Inequity and Climate: A Common Theme

In many of the 80 most climate-vulnerable countries, population growth is tightly linked to persistent gender inequity, including a lack of meaningful access to family planning and reproductive health services. The new Population Institute report also incorporates findings from the Gender Inequality Index (GII), which reflects gender-based disadvantage in three dimensions—reproductive health, empowerment, and the labor market. The index ranges from zero (where women and men fare equally) to 1 (where women fare as poorly as possible in all measured dimensions).

The report’s analysis reveals that the average GII in the 80 most vulnerable countries is 0.521 (GII in the United States, by contrast, is 0.179). This suggests that greater investment in gender-responsive adaptation strategies—those that seek to promote gender equality and tap into the potential of women and girls as powerful agents of change—is warranted.

A broader embrace of sexual and reproductive health and rights (SRHR) is also critical to advancing gender equity in the face of climate change challenges. Access to voluntary family planning and other sexual and reproductive health services fosters gender equity by improving women’s health, empowering women, and freeing them to pursue education, employment, and other life opportunities. One key component is the ability to achieve one’s desired family size and avoid unintended pregnancy, and yet, nearly half of all pregnancies worldwide are unintended—a trend that the UN Population Fund has called a “neglected crisis.”

The ability to plan and space births better equips individuals and families to navigate and survive shocks and stressors in their lives, including the impacts of climate change. Over the long-term, it will also slow population growth by enabling people to avoid unintended pregnancy and achieve their desired family size. Yet the report’s analysis also indicates that among the most climate-vulnerable countries for which there is data, the average unmet need for family planning among women who would like to delay pregnancy or end childbearing is nearly double the global average.

Finding Hope in Multisectoral Global Initiatives

These investigations into gender inequity and deficits in sexual and reproductive health and rights demonstrate how they intersect with climate trends to exacerbate vulnerability and limit people’s adaptive capacity. With these connections in mind, however, it is also possible to imagine climate change adaptation strategies that both incorporate their consideration and include interventions designed to tackle them.

The report highlights significant efforts made by communities and organizations in five countries to pioneer approaches that integrate population, reproductive health, and gender equity to foster resilience to climate change.

As a nation made up of more than 7,000 islands, the Philippines is highly vulnerable to sea level rise, extreme weather, and fisheries degradation that threaten its residents. For more than two decades, PATH Foundation Philippines (PFPI) and other organizations in the Philippines PHE Network have developed integrated strategies to improve natural resource management, deliver greater reproductive health services, and enhance food security.

“Residents and policymakers alike believe that with sexual and reproductive health and rights, families and communities are healthier,” says PFPI’s Joan Castro. “This contributes to building climate change resiliency and allows more time and resources for conservation and community initiatives–all of which increase resilience to climate change and slow population trends that exacerbate poverty and climate change impacts.”

Uganda is the 13^th most vulnerable country in the world, but Regenerate Africa works with other organizations and multiple government agencies to foster multisectoral policies and programs to bolster its climate change adaptation. Their advocacy efforts have resulted in a clear articulation of the need to strengthen gender equity and reproductive health in national climate policies, including the Ugandan government’s climate commitments in its most recent Nationally Determined Contribution.

“Across Uganda, families and communities experience intertwined challenges of rapid population growth, gender inequity, and climate change vulnerability,” says Charles Kabiswa of Regenerate Africa. “In this context, multisectoral strategies offer hope for long-term, collective benefit.”

In Guatemala, the conservation NGO FUNDAECO pursues climate change activities, including a REDD+ project that supports women’s reproductive health and empowerment, as well as a girls’ scholarship program. “Once women have access to health and family planning services, and they are empowered in their rights, it is a natural next step that they are willing to participate in natural resources management and income-generation activities,” says FUNDAECO’s Ingrid Arias.

A team from the Center for Biological Diversity conducted an analysis of 21 municipal climate plans across the United States in 2022, seeking to understand how municipalities account for the gendered impacts of climate change. While the results of their analysis were disappointing (only two plans acknowledged that women face unique climate-related vulnerabilities), their research sheds light on what is needed for the future.

“The status of women is inextricably linked to the health of our environment and climate,” says Kelley Dennings of the Center. “Through empowerment strategies like gender justice, reproductive freedom, education, and equity, women are better able to adapt to climate change and become more engaged in climate solutions.”

And in Niger (the world’s most climate-vulnerable country as ranked by ND-GAIN), the population is growing at about 3.7 percent annually—a growth rate that, if it remained unchanged, would result in a doubling of the population in just 19 years.

With recurring challenges linked to environmental degradation, pervasive poverty, political instability, and climate change, the youth-led climate advocacy organization Juenes Volontaires pour l’Environnement (JVE) has much to tackle. Yet Sani Ayouba of JVE is encouraged by local leaders who understand that increasing their budgets for voluntary family planning makes sense as a climate resilience strategy. “Their perspectives need to be heard,” says Sani. “Frankly, they know better.”

Today’s Investments Will Shape Our Future

World Population Day encourages us to take a step back and consider a long view of how population issues will shape our future. Climate change is a long-term challenge to which humanity must respond—and, over the long term, the size of the human population will be among the decisive factors that ease or complicate that response.

But population numbers can’t tell the story on their own. We also must know where people live, how they live, the agency they have in their lives, and what access they have to resources and opportunities. Understanding these factors—and how they combine—is critical to developing a vision of how population growth will affect our future and our abilities to manage the climate crisis. The initiatives highlighted in this report demonstrate promising possibilities for multisectoral approaches that respond to these complexities. While small in scale, they suggest what could be accomplished if governments and societies develop and scale up initiatives based on similar integrative strategies.