Scientists: Defusing the Population Bomb Won’t Save the Planet
A new study claims that even the strictest fertility controls can’t solve issues of global sustainability, and even a catastrophic plague event wouldn’t put a dent in the inevitable human population growth at this point.
We’re “virtually locked in” to a population expansion of between 5 billion and 10 billion people by 2100, according to the study’s coauthors, Corey Bradshaw and Barry Brook of the University of Adelaide in Australia.
The study, published on Tuesday in the Proceedings of the National Academy of Sciences, examined nine models of population growth, ranging from “business as usual” to estimates that accounted for global pandemics and a war resulting in billions of deaths. In every scenario, the human population inevitably rose.
“We were surprised that a five-year WWIII scenario mimicking the same proportion of people killed in the First and Second World Wars combined, barely registered a blip on the human population trajectory this century," Brook said in a statement.
Blame the baby boom. The post–World War II population explosion accelerated the birth rate to such a degree that reversing our growth has become almost impossible, at least through 2100, the authors wrote.
“Had humanity acted more to constrain fertility before this enormous demographic momentum had developed (e.g., immediately following World War II), the prospect of reducing our future impacts would have been more easily achievable,” the study states.
Even a worldwide one-child policy such as China’s wouldn’t stop population growth over the next century.
“Global population has risen so fast over the past century that roughly 14 percent of all the human beings that have ever existed are still alive today—that’s a sobering statistic," Bradshaw, an ecologist, said in a statement. "This is considered unsustainable for a range of reasons, not least being able to feed everyone as well as the impact on the climate and environment."
Environmentally, this is bad news. Since 1800, the world’s population has grown sevenfold to 7.2 billion. The global population will reach 9.2 billion by 2050 and 10.9 billion by 2100, according to United Nations estimates. In that same period, carbon dioxide emissions have grown by 150 times.
The controversial silver bullet of population control appears to be a blank.
"Often when I give public lectures about policies to address global change, someone will claim that we are ignoring the 'elephant in the room' of human population size,” Brook said. “Yet, as our models show clearly, while there needs to be more policy discussion on this issue, the current inexorable momentum of the global human population precludes any demographic 'quick fixes' to our sustainability problems.”