Does Population Growth Impact Global Climate Change?

Most informed people know that the global population is growing at a rapid rate — putting added pressure on our already limited supply of resources. But it remains difficult to communicate the sheer scale of the population challenge. Moreover, quantifying the extent of population growth’s influence on global climate change can be both difficult and controversial.

But, just because something may be controversial does not mean we should ignore it. It’s clear that as more people are added to the planet, climate change only intensifies, and its devastating effects become more harmful to all of humanity.

Population Growth’s Impact on Global Climate Change

Looking back over the last several centuries, global population trends show continuous expansion, both in terms of volume and rapidity. Even now, humanity is near its all-time highs.  As Global Population Speakout explains: “It is estimated that the world population reached 1 billion in 1804. It was another 123 years before it reached 2 billion in 1927, but took only 33 years to reach 3 billion in 1960. Thereafter, the global population reached 4 billion in 1974 (14 years), 5 billion in 1987 (13 years), 6 billion in 1999 (12 years), and 7 billion in 2011 (12 years).” We are expected to pass 8 billion in early 2023 — adding a billion in the 13 years since 2011.

Today, the global population grows by about 80 million people each year, or nearly 220,000 people every day. That’s 220,000 new people who will add their own unique carbon footprint to the planet for the duration of their lives. Of course, richer people tend to have a greater carbon footprint than the less affluent, but the latter are most likely to disproportionately bear the brunt of the damage.

With every new human comes a greater likelihood for greenhouse gasses to flow into the atmosphere. Interestingly, humankind breathes out about 140 billion carbon dioxide breaths every minute. But more importantly, with each new human, we drive more cars, build more residential and commercial structures, and eat more food. In fact,  the global food production system is one of the most significant drivers of global warming. As human population grows, our overall demand for food increases, and already the global food production system contributes roughly 30% of greenhouse gas emissions.

Our current industrial civilization almost wholly depends on fossil fuels, and not just for powering our vehicles. We use fossil fuels, especially oil, to manufacture vehicles, farm equipment, fertilizers and pesticides, agricultural plastics and so much more. Then, we use fossil fuels to propel cars and trucks, tractors, airplanes, and ships. Our current industrial agriculture system—like so many other aspects of modern life—couldn’t function without fossil fuels. 

Climate Change Is Already Here

It can be easy to think of climate change as a threat that will only impact us in the future. But in reality, it’s already here. 

As a result of our unmitigated population growth and reliance on fossil fuels, we’re seeing the dramatic effects of global warming play out before our very eyes. Global average temperatures have already increased by more than one degree Celsius since pre-industrial times, and carbon dioxide levels in the atmosphere are higher than they’ve been in more than 800,000 years. 

For clarity, let’s explore the difference between the terms “climate change” and “global warming.” Although sometimes used interchangeably, important distinctions exist between the two concepts. According to NASA’s definitions of the terms:

• Global warming is “the long-term heating of Earth’s climate system … due to human activities, primarily fossil fuel burning, which increases heat-trapping greenhouse levels in Earth’s atmosphere.” 
• Climate change refers to “both human- and naturally produced warming and the effects it has on our planet,” and it is typically measured as the average increase in global surface temperature.

At Population Media Center (PMC), we are primarily concerned with human-forced global warming, because that’s where the opportunity lies for change. The need for change is urgent: NASA reports that human activities are increasing the global average temperature by 0.36 degrees Fahrenheit, or 0.2 degrees Celsius, every 10 years. 

We are already seeing many signs that global warming is happening. For example, in June, a small Siberian town that sits within the Arctic Circle recorded its hottest-ever temperature, hitting 100.4 degrees Fahrenheit. It’s likely a record high for the Arctic Circle and a disturbing glimpse into the future.

Another example of climate change in action is the thousands of species that are shifting their habitats northward in an attempt to flee warming temperatures. Analysis of animal migration patterns has shown that marine species are moving closer toward the Earth’s poles by six kilometers a year, on average. Amphibians are moving 12 meters a year, while insects are shifting north by about 18.5 kilometers. These troubling trends indicate that vast regions are becoming uninhabitable for certain species—a reality that many humans could soon face, as well.

Improving Sustainability by Empowering Women and Girls

Lifestyle changes, such as driving less and committing to recycling, aren’t enough to stop climate change. As the authors of an Oregon State study explained, our best chance for addressing global warming is to solve the problem of overpopulation: “The potential savings from reduced reproduction are huge compared to the savings that can be achieved by changes in lifestyle.”  

A 2017 study by the Universities of Lund and British Columbia found that the “single most effective measure an individual in the developed world” could take to reduce their carbon emissions is to have one fewer child. 

Sadly, the decision to have fewer children is not available to everyone. Millions of women around the world do not have the choice of whether or when to have children, or how many to have.

In many countries, women cannot achieve reproductive autonomy because of a variety of obstacles, including:

• Gender-based violence, such as domestic violence and rape
• Harmful traditional practices, such as child marriage and female genital mutilation
• Economic discrimination
• Reproductive health inequities

Of course, protecting and empowering women and girls is an ethical imperative. Working toward greater gender equity, and undoing the damage of the practices above, is a goal in its own right. But empowering women and girls also has important parallel benefits, including the chance to slow human-caused global warming. 

We can improve sustainability by promoting behavior changes that help improve the status of women and girls. When we empower women and girls, they are better equipped to determine their futures—which includes their reproductive destinies. 

When women can choose to have fewer children, population trends will become much more sustainable. According to the United Nations, the global population in 2050 will be somewhere between 8.96 billion and 10.58 billion, depending on fertility rates. If global fertility rates decrease by just 0.5 children per woman, we will have 3.5 billion fewer people by 2100, lessening the impact of climate change. 

Behavior Change in Action

At PMC, we harness the power of well-crafted educational entertainment to generate positive behavior change. To help solve the big, long-term problem of population growth, we focus on the here and now: improving knowledge and attitudes that will lead to greater empowerment for women and girls. 

An example of our work in action is the radio show Agashi (“Hey! Look Again!”), which reached more than 2 million residents of Burundi. The show served as a valuable educational resource, teaching listeners about important topics such as how to avoid unwanted pregnancies and disease. Agashi achieved widespread change in Burundi for a relatively modest price: just $0.74 USD to reach each listener.

When we explore the level of change brought about by Agashi, we can calculate the cost of individual changes attributable to the show:

• The estimated number of listeners with improved knowledge of family planning methods was 248,000. Accounting for the costs to produce the show, the Cost per Attributable Knowledge Change comes to approximately $6.70 US.
• The estimated number of listeners who were voluntarily tested for the AIDS virus within 24 months of the survey was 293,091. That amounted to a Cost per Attributable Behavior Change of $5.67 US.
• The estimated number of listeners with increased agency to negotiate condom use during sexual intercourse was 270,546, which amounts to a Cost per Attributable Change in Agency of approximately $6.14 US.

When you combine the numerous social issues that were impacted by one show, the cost per overall change lowers dramatically. 

Now Is the Time to Act

As we explored above, we are in the era of climate change, and we must pay attention. Our civilization is facing an existential crisis that requires remediation today and building a new tomorrow. 

Evidence all around us indicates that we are barrelling toward a catastrophe, but we must respond carefully in order to be effective. It’s important to be judicious with our investments and programs so we don’t simply put band-aids on deep, systemic problems. 

We all must advocate for social and ecological sustainability and shine a spotlight on our world’s systemic challenges. We must encourage innovation, movement building, and creative partnerships for progressive programming and public education. 

As part of these efforts, educational entertainment and behavior change communications are measurable, cost-effective interventions that enhance human rights. Shows like Agashi and other PMC programming attend to the immediate needs of audiences while also creating long-term systemic change—exactly what this moment calls for.