8 Billion of Us! – Population Growth and Climate Change

Sometime on November 15th, according to demographers, a baby was born somewhere in the world who brought the number of humans living on the planet to 8 billion. That’s a lot of us!

How does population growth relate to our efforts to solve the climate crisis? This is a sensitive subject. It can bring up differing viewpoints and strong feelings about everything from women’s rights to religion to racism.

There’s no question that, all other things being equal, more people means more consumption; and more consumption means more stress on multiple global systems, including the climate. However, population growth does not have as large an impact on the climate crisis as one might suspect.

First of all, worldwide population growth has slowed significantly and is now less than 1% per year.

Greatest population growth is where per capita emissions are low
Secondly, most population growth is occurring, and will occur in the coming decades, in sub-Saharan Africa and south Asia–areas of the world where per-capita greenhouse gas emission rates are very low. Population growth in these areas contributes to climate change, but the contribution is extremely small compared to the amount of climate change driven by the consumption patterns of people in the wealthy nations. In other words, our over-consumption problem in the wealthy nations is far greater than the population growth problem elsewhere.

Kenya, for instance, has a population of 55 million people–about 95 times the population of the state of Wyoming. Yet Wyoming emits 3.7 times more carbon dioxide than Kenya. According to APNews, “Africa as a whole has 16.7% of the world’s population but historically emits only 3% of the global carbon pollution, while the United States has 4.5% of the planet’s people but since 1959 has put out 21.5% of the heat-trapping carbon dioxide.”

Per capita emissions
Among the populous nations the highest per capita emissions are in Canada (15.4 metric tons), Australia (15.2t), the U.S. (14.7t). The world average is 4.7t. One might think that high standard of living and high per capita emissions inevitably go hand in hand. However, some countries with high standards of living have much lower per capita emissions than the U.S. For example: the UK (5.2t), France (4.5t), Portugal (4.3t) and Sweden (3.4t). These countries are growing their economies while reducing their emissions. Much, but not all, of the difference between these European countries and the U.S. is the result of their greater use of renewable energy. (Since I mentioned Kenya above as one of the poor, low-emitting nations, I looked up its per capita emissions. Answer: 0.4t.)

Scientists at Climate Interactive ran computer simulations to determine the effect of population rise on global temperature increase. They found only a 0.2°C difference between the scenario in which global population increased to 10.4 billion and one where the increase was only to 8.8 billion people. For comparison, they ran simulations of the effect of enacting a global tax on carbon of $100/ton and found it made more than 3 times more difference (0.7°C).

What matters most
So, if we want to make a difference in global emissions of greenhouse gases, and we do, of course, it makes more sense to focus on reducing the emissions of high-emitting nations than it does to try to pursue population control in the poor nations of African and Asia. As Somini Sengupta wrote in the New York Times, “Actually, what matters most is not how many we are. It’s how we live.”

Project Drawdown
That said, universal access to voluntary family planning for women, girls, and couples is an essential human right. So is universal access to education for all children. It turns out that when these things are both available, a great many people make good use of them. Education and the availability of family planning service tend to lead to “improved livelihoods, better economic opportunities, delayed onset of marriage, and delayed childbearing” (Project Drawdown). There are many benefits and one of them is slowed population growth.

Project Drawdown has examined how much increased investments in universal education and universal access to voluntary family planning services could slow global population growth. Then they looked at the difference that reduced population growth would have on greenhouse gas emissions. They found that the effect could be a reduction of 68.9 gigatons of CO2 equivalent emissions between 2020 and 2050. That’s enough to make “Family Planning and Education” one of their top ten “solutions” for solving the climate crisis.

In the wealthier nations
Almost half (45%) of this reduction in emissions is projected to come from reducing births in the wealthy nations, where per capita emissions are high and many pregnancies are still unwanted. It’s estimated that in the United States, for instance, nearly half of all pregnancies are “unintended”, with 27% “wanted later” and 18% “not wanted”.

Obviously, we should be making education and access to family planning universal as a matter of basic human rights and for all the other benefits that come from them. It is serendipitous that they also have such a beneficial effect on global emissions.

We can pursue both strategies
While population growth is not one of the major drivers of global warming in the coming decades, it is one of many areas where some wise policy and investments can make a significant difference. Even larger differences can be made by reducing the per capita emissions in all the wealthier nations. We don’t need to choose between these strategies, we can pursue them all as part of our caring for our planet and all its inhabitants.

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The photo above was taken in Arches National Park, Utah, USA, by Amy Vernon-Jones

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