A 'baby bust' may be welcome in a hot and hungry world

The 2020 census reported the lowest rate of population growth in the U.S. since the post-Depression decade, inspiring a chorus of economic Cassandras who want to reverse this trend. To shore up economic growth, they argue, we need to "raise fertility" and "avoid becoming yet another graying, stagnating wealthy society," perhaps even tripling our population to "one billion Americans."

But while the census numbers do offer a solid argument for immigration, the case for boosting birthrates fails to acknowledge the increasing difficulty of nourishing a more populated world.

Before clamoring for more mouths to feed, we need to recognize the dire realities of world hunger today and the gravely concerning predictions for famine and malnutrition in the decades to come. Let's get a plan in place to ensure climate stability and greater food security going forward. Until then, a slowdown in population growth not only eases pressures on a stressed planet, it will make it possible to feed more people more intelligently and sustainably, with higher-quality food.

Let's first establish that declining population trends are occurring well beyond the United States. Researchers at the University of Washington's Institute for Health Metrics and Evaluation reported that as of 2017, the global fertility rate had fallen by nearly half since 1950, to 2.4 births per woman from 4.6. They expect the world to reach a peak population of 9.7 billion inhabitants around 2060 before dipping to 8.8 billion by 2100.

Twenty-three nations — including Italy, South Korea and Japan — are expected to see their populations reduced by more than half within that 2017-2100 time frame.

For now, though, even feeding 9 billion people by midcentury looks like an iffy prospect.

Birthrate declines are occurring alongside a concurrent trend: hunger. After falling for decades, global food insecurity is rising again, driven by extreme weather, political conflict and economic slowdowns intensified by the COVID-19 pandemic. Roughly 700 million people in the world are undernourished — a surge of 60 million in five years and almost 10% of the world population, according to a new report from the United Nation's World Food Program.

While we're adding 2 billion people to the planet in the next 30 years, global crop yields are expected to plummet. Climatic models show a decline in global crop yields every decade going forward as the pressures of global warming intensify, punishing food producers with drought, heat, flooding, superstorms, invasive insects, shifting seasons and bacterial blights.

In the U.S. alone, powerful "derecho" storms damaged 10 million acres of Iowa's cornfields last summer. The previous year, drenching rains wiped out billions of dollars of corn and soy production when the fields were too wet for machinery to run. Wildfires devastated wine and cattle producers in northern California, and blights and hurricanes wiped out citrus and nut production in the American southeast.

By midcentury, the world may reach a threshold of global warming "beyond which current agricultural practices can no longer support large human civilizations," the International Panel of Climate Change has warned. U.S. Department of Agriculture scientist Jerry Hatfield put it to me this way: "The single biggest threat of climate change is the collapse of food systems."

Yet I'm hopeful about our food future — and about the health and future of the global population. I know that "current agricultural practices" will give way to smarter and more sustainable food production. I've traveled from apple orchards in Wisconsin and tiny cornfields in Kenya to massive Norwegian fish farms and computerized foodscapes in Shanghai to investigate new ideas, including robotics, CRISPR and vertical farms.

Old ideas can make a difference, too, such as edible insects, permaculture, and a revival of ancient plants. I know that farmers and entrepreneurs are radically rethinking national and global food systems to make them resilient and sustainable.

The current population slowdown is appropriate given the realities of food insecurity that are now upon us. The U.N. now says its global target of Zero Hunger by 2030 is looking impossible to reach. Only when we — in the U.S. and as a global collective — come up with achievable goals for feeding humanity responsibly and sustainably should we commit to the goal of boosting birthrates.