In an article in Wednesday’s paper, we conveyed the highlights of a new report from the United Nations population division projecting that the global population will keep growing throughout this century and eventually pass 10 billion. And we mentioned that the population is expected to surpass seven billion this year.
It turns out the United Nations has settled on an official date by which it expects the world to hit that seven-billion mark: Oct. 31. Nobody really knows for sure, of course — our sense of the world’s population at any given moment is an estimate at best. Still, perhaps it’s appropriate that the chosen date falls on Halloween, given how scary the population problem looks to many people.
The new calculations, based on improved methods and the most recent demographic trends, essentially add a billion people to the population projection for 2100, and about 150 million to the projection for 2050. If these projections are borne out, the world’s environmental challenges, already profound, will only deepen.
The United Nations population estimates are fed into an array of computer models, in institutes around the world, that try to project future economic and environmental trajectories. Expect a flurry of updates in coming months on projections for climate change, land use, water availability and many other issues as the consequences of these revisions work their way through the world of scientific prognostication.
Even before the new estimates were issued, it was not at all clear that global agriculture could keep up with demand, which is rising both because of population growth and income growth. Even if food production does keep up, many experts worry that the environmental damage from agriculture, already substantial, will grow worse; it is already one of the biggest contributors to the greenhouse gases that are causing global warming.
On top of that, an extra billion people will demand energy, much of which may need to come from burning fossil fuels, thus adding to the greenhouse problem.
The big question is how far the population curve can be bent.
Recent decades offer evidence that a sustained focus on the issue could yield dividends in the relative handful of countries that are still growing fast — chiefly in Africa and South Asia. For instance, the mullahs of Iran figured out a way to offer family planning in a culturally sensitive way, and the result has been a sharp decline in fertility in that country. By varied methods, countries as diverse as Mexico and Sri Lanka have accomplished the same thing.
In the past 15 years or so, international family-planning programs fell victim to a series of ideological battles over abortion, sex education and the social role of women. Budgets stagnated. More recently, in the United States, the Obama administration has pushed to expand financing for such programs, especially in Africa.
But in the budget battles on Capitol Hill, that has been a hard sell, and the programs took a 5 percent cut in the recent budget deal. Prospects for the budget year that begins Oct. 1 are cloudy.
In an interview on Tuesday in Johannesburg, Rajiv Shah, who heads the United States Agency for International Development, sought to make the best of a difficult political environment for foreign aid and family planning. While acknowledging that family planning has long been a neglected priority, he said that President Obama was personally committed both to Africa and family planning and had done his best to protect the budget for such programs.
Mr. Shah’s agency, known as USAID, is the principal government agency that helps to fund global development. He said he himself was aiming to make taxpayers’ money go further with reforms to the agency’s procurement practices, rigorous evaluation of programs to measure results, and the restoration of the agency’s expertise with the hiring of hundreds of foreign service officers.
During the Clinton administration, the agency had increasingly turned to contractors to deliver services and had lost much of its in-house ability to manage its sprawling global programs. Mr. Shah said the agency was also collaborating with the British development agency and the Bill & Melinda Gates Foundation in an effort to prevent 100 million unwanted pregnancies in coming years in 21 countries with the greatest need.
In the long run, he said, recent success in reducing infant and child mortality across the continent would help bring down the number of children couples feel they must have.
In many poor countries that have no social security system for the aged, children are their parents’ insurance. Until couples have confidence that their children will survive into adulthood, they will be likely to have more children as a hedge against the death of some. And it takes time to trust in the improved odds your children won’t succumb to diarrhea, measles, malaria or other common killers.
John May, a World Bank demographer and expert on Africa’s population patterns, estimated that it could take 10 to 20 years for declines in infant and child mortality to translate into reduced fertility for women.
“It’s the expectation of survival you have to change,” Mr. Shah said. “That takes a longer period of time.”
Despite worries about fast population growth in the poorest countries, the new United Nations report highlights a sort of paradox in the population estimates: some of the world’s wealthiest countries are worried not about growth but about the opposite problem: stagnant or falling populations.
That’s because fertility in many of these countries has dropped below replacement level. It’s not clear they will have enough young workers in future decades to support retirement programs for the elderly.
The contrast between the situation of these post-industrial societies and that of fast-growing poor countries is hard even for demographers to fathom. “It’s stunning, and I don’t use that word a lot,” said Carl Haub, a demographer with the Population Reference Bureau in Washington. “There’s a chasm between much of the developing world and the industrialized countries.”
Coupled with longer life spans, the trend means that societies like Japan, Russia and South Korea are expected to age rapidly. The Japanese population is projected to decline from today’s 126 million to 91 million by the year 2100. The Russian Federation is projected to decline from 142 million to 111 million. “A lot of countries are in panic mode — South Korea, Taiwan, Germany,” Mr. Haub said.
He pointed out that fertility in Taiwan had fallen below one child per woman on average, less than half the rate required for a population to replace itself. “Who ever would have expected that?”