“Worrying” population declines are actually a hopeful sign
This article first appeared in Newsweek on June 12, 2024.
Human population is in the news, but not for the reasons we are used to. At one time, our growing population was seen as central to wildlife extinctions, resource depletion, pollution and environmental destruction. But today, we are more likely to hear that there are too few of us, not too many. As women across the world have gained greater reproductive choice, birth rates have declined.
This is a positive development in large part due to a decline in teen pregnancy, but you would never know it from news coverage of the topic that ranges from anxious to apocalyptic. The birth rate "crisis," we are told, will have dire consequences for our economy and especially for seniors. Lost in the conversation are the many positive aspects of an aging society, which is the result of people living healthier and longer lives, and common-sense realities like reduced needs for infrastructure and lower ecological impacts. Also lost is the fact that our population still grows by 80 million people every year, from places in the world where women and girls lack reproductive choice and face powerful pronatalist pressures, whether to carry on a family line, grow a religious denomination, or fuel economic growth with more consumers and cheap labor.
And the consequences are dire. Among them is global warming, which the Intergovernmental Panel on Climate Change warns is driven by both population and economic growth. In fact, increased emissions from population growthhave canceled more than three quarters of the emissions saved through energy efficiency and renewables over the past three decades.
Yet, no matter how well documented the link between population and climate, lowering our population is conspicuously absent from the conversation on solutions. Instead, the focus is on technology that will supposedly allow our entire growing population to enjoy the energy-intensive lifestyles now enjoyed by the rich, and with no climate impacts.
But "green" technology is not the solution it is cracked up to be. Its buildout to the degree needed to power a growing population at a decent standard of living would itself require a staggering investment in fossil fuels. It will also require massive mining operations. Batteries for electric vehicles use lithium from places that cannot spare the enormous quantities of water required for its extraction, places like parts of Nevada sacred to Native Americans and the deserts of Bolivia. Other mining for lithium, as well as for copper, nickel, and cobalt needed for wind turbines and electric cars, takes place on the backs of low-wage workers, many of them children, in Africa where it is driving destruction of rainforests critical to the survival of great apes. The next frontier for mining these minerals is the deep seabed, where extraction threatens endemic and undiscovered species. And the minerals are destined for renewable energy infrastructure and transmission capacity with impacts of its own: it requires 10 times the land area as fossil fuel plants for the same amount of energy generated.
And of course, it bears remembering that electricity is only 20 percent of global energy demand—the rest is devoured by air travel, shipping, steel production, and other sectors whose "decarbonization" is difficult to imagine.
In short, providing even "green" energy for 8 billion and counting will have ecological impacts that are seldom discussed. The impacts of feeding that many are even more chilling. At our current population and rates of consumption, agriculture takes up 40 percent of Earth's ice-free land area. Primarily through deforestation and habitat destruction, it is the leading threat to 86 percent of species at risk of extinction and consumes 70 percent of the planet's freshwater. These impacts are not just from industrial agriculture; globally, subsistence agriculture is responsible for 33 percent of deforestation while large-scale commercial agriculture drives 40 percent.
It is difficult to imagine how food production can expand to feed the additional 2 billion people projected by 2100 without further devastating Earth's biophysical systems. The rapidly growing global middle class and its preference for meat-heavy diets has dire ecological implications, as animal agriculture uses the vast majority of farmland and is responsible for 60 percent of the greenhouse gas emissions from agriculture.
The extraordinary ecological impacts of expanding animal agriculture are not surprising when you consider its scope: in the past 50 years, as the world's population has more than doubled, the number of land animals slaughtered globally has increased from 12 billion to 80 billion. Today, of the total biomass of terrestrial vertebrate species, 60 percent is livestock, 36 percent is humans, and 4 percent is all living wild mammals, birds, reptiles, and amphibians.
While the mass of living creatures is dominated by humans and our livestock, the sheer mass of human-made things, from cellphones to interstate highway systems, has exceeded the weight of all living things and grows by 30 billion tons annually. One of the side effects of our massive technosphere is pollution on a scale that threatens what living biomass remains. Pollution can be difficult to ignore, like the great Pacific garbage patch whose area is twice the size of Texas and which is largely made up of discarded fishing gear, or the toxic air pollution that jeopardizes human health in densely populated cities like New Delhi. Or it can be more insidious like the agricultural nutrient runoff causing 78 percent of global ocean and freshwater eutrophication—degradation of freshwater that is becoming perilously scarce due largely to animal agriculture, which uses 1,800 gallons of water to produce one pound of beef.
When global heating threatens to push billions outside of temperature limits compatible with human life, it is no time to panic that we are adding fewer to those billions. In fact, declining birth rates should be cause for celebration for all they signify about gender equality, children's wellbeing, and easing our burden on Earth. Rather than lamenting low birth rates and strategizing about pronatalist coercion that might reverse them, we should embrace and adapt to this positive trend and celebrate what it means for our planetary future.
