A recent article in the Proceedings of the National Academy of Sciences (PNAS) has ignited a small firestorm of criticism. As reflected by its title, "Human population reduction is not a quick fix for environmental problems," the authors argue that reducing projected population growth rates, by itself, would not have an immediate impact on environmental threats like climate change. In a broad sense that's true, but it is sort of like saying that "Reducing fossil fuel emissions is not a quick fix for climate change."
While fossil fuel consumption is one of the primary drivers of climate change, even the most optimistic scenarios for reducing fossil fuel consumption over the next 5-10 years would have little or no effect on global warming over the next two or three decades. Scientists, in fact, are now warning that an increase of 2 degrees Celsius is virtually locked-in. But anyone who is truly concerned about climate change is not giving up on reducing fossil fuel consumption. It's late in the climate change game, but not so late that we should give up on curbing carbon emissions.
The same is true with respect to population growth and its environmental impact. Humanity, with 7.2 billion people on the planet, is already over-utilizing planetary resources. With respect to our use of renewable resources, the Global Footprint Network asserts that we will need two Earths by 2030 to sustain us for the long haul. And if, as many demographers now predict, world population grows to 9.6 billion by 2050 and to 10.9 billion by the end of the century, the environmental impact with respect to climate change, loss of biodiversity, deforestation, and the acidification of the oceans could be severe and, in many areas, irreversible.
In their article the authors conjure up various demographic scenarios to determine the likelihood of a significant decline in global population by the end of the century. They found that even with a "draconian fertility reduction to a global one-child per woman by 2100" world population would still rise to 8.9 billion by 2050 and subside to only 7 billion by the end of the century.
The authors, thankfully, were not advocating for a global one-child policy; they were simply using the scenario to illustrate the difficulty of slowing population's momentum. But coercion, in addition to being morally wrong, is not necessary to achieve a rapid reduction in fertility. Women in China today have an average of 1.6 children. Three of its neighbors have achieved lower total fertility rates without a coercive mandate: Japan (1.4), South Korea (1.2), and Taiwan (1.1). And other countries in Asia, like Thailand, Iran, and Vietnam, have achieved comparably sharp reductions in fertility without resorting to mandates.
Corey Bradshaw, the lead author of the PNAS article, insists that he and his co-author were not dismissing the benefits of family planning. In his blog he writes, "On the contrary, we should implement global-scale family planning. Hundreds of millions fewer people stressing our planet's resources and biodiversity could result if we do, and if we don't start somewhere, slowing the speeding car in the future will be even more difficult than it already is."
Their article, however, plainly argues that the short- and intermediate-term benefits of family planning are quite limited. While acknowledging that there are "environmental and societal benefits" to expanding the availability of contraceptives, the authors conclude that, "It is a solution long in the making from which our great-great-great-great grandchildren might ultimately benefit, rather than people living today." And that is where the authors go terribly, terribly, terribly wrong.
Family planning is enormously consequential in developing countries and the benefits do not take long to materialize. Enabling women to space and limit their pregnancies reduces maternal and child mortality. In turn, smaller, healthier families improve food security, boost educational attainment levels, promote gender equality, and help to fight poverty.
In poor, population-stressed environments, family planning can have a transformative impact in a generation or less. In rural areas where women currently have five to six children on average, the introduction of family planning services and information can cut average family size in half within two decades. By doing so, they can help slow rates of deforestation, avert the depletion of underground water resources, and give sanitation and waste management efforts a fighting chance. Family planning is certainly not a "silver bullet," but it can contribute to the preservation of critical bio-habitats and improve the odds that endangered species will survive. Population is, and will likely remain, a significant environmental factor at the local level.
And the same is true with respect to climate change. An earlier study, which was published in PNAS four years ago and authored by Brian C. O'Neill, concluded that "slowing population growth could provide 16-29 percent of the emissions reductions suggested to be necessary by 2050 to avoid dangerous climate change." That may not qualify as a quick fix, but it demonstrates, once again, that population matters.
The authors of the recent study contend, and rightly so, that family planning, by itself, is not going to save the planet; we still must curb pollution and rein in our consumption of scarce resources. And we must use technology to preserve the natural world, rather than exploit it. But no one should diminish, intentionally or not, the central role that family planning must play in reducing the escalating demands that we are currently placing on the planet.