On November 15, the 8 billionth person on the planet was born. Well, more or less. That was the date selected by United Nations demographers as the moment the world crossed its latest population milestone. The exact date is probably wrong—perhaps off by months or more—but there are roughly a billion more humans alive today than there were 11 years ago.
I hadn’t been paying close attention to the Day of 8 Billion. Milestones make good headlines, but concentrating on a few big numbers can obscure more revealing trends that really explain how the world has changed since there were just 7 billion of us. Here are two examples. The proportion of people living in extreme poverty has steadily declined over the past decade. (In 2010, 16.3 percent of the world lived on less than $2.15 a day, while today only 9 percent of people live on such a paltry amount.) And in India and China—which contributed the most new births in the past decade—GDP per capita and life expectancy have risen even while populations boomed. To put it simply, more people are living better lives today than at almost any other point in human history.
As the Day of 8 Billion rolled around, my inbox filled with a steady drip of press releases warning that the milestone represented a planetary crisis point. I have a hunch as to why I was getting these stories sent my way. A couple of months earlier, I’d written an article about why Elon Musk is wrong to worry about falling populations. In the near term, demographers pointed out to me, the world’s population is only heading upward. Managing that increase is the real challenge facing the planet right now. In the eyes of NGO press officers and certain angry people on Twitter, this put me firmly in the camp of “journalists who are convinced that we should be less afraid of talking about ‘overpopulation’ and its effect on the environment.”
A lot of online coverage about the Day of 8 Billion came from the same perspective. “It should not be controversial to say a population of 8 billion will have a grave impact on the climate,” read one headline in The Guardian. On a basic level, that’s completely true. If everything else stays the same, more people on the planet will mean higher carbon emissions. The climate solutions charity Project Drawdown estimates that providing better family planning and education will help avoid 68.9 billion metric tons of CO2 emissions by 2050—roughly equivalent to two years of emissions from fossil fuels and industry.
We need to tread carefully when we talk about population and climate change. It’s easy to look at a world of 8 billion and conclude that there are “too many” people on the planet. But who do we really mean when we talk about overpopulation? Someone living in the United States is responsible for about 15 metric tons of CO2 emissions per year. But in the eight countries where the majority of population growth by the year 2050 will be concentrated, per capita emissions are just a fraction of US levels. In the Democratic Republic of Congo (DRC), which is projected to grow by more than 120 million in the next 20 years, each person produces just 30 kilograms of CO2 each year. Emissions are a consequence of consumption, not just population.
The world’s richest people are the biggest emitters. One study from the World Inequality Lab found that as emissions have fallen for the middle class in rich countries, those from the top 0.001 percent have risen by 107 percent. “When I see rich people with massive families I think, no, we don’t have the capacity to have more rich people on the planet,” says Lorraine Whitmarsh, a psychologist at the University of Bath who studies behavior and climate change. If we really want to reduce emissions, then starting with reducing consumption in the developed world, where populations are stagnant, makes the most sense.
But reducing people to their per-capita emissions comes with its own problems. Humans aren’t tradable carbon chips, and climate interventions aren’t just about reducing emissions.