polis: a collective blog about cities worldwide

Should We Worry About a Global Population Explosion?

by Katia Savchuk

Sometime this year, the global population will reach 7 billion, according to United Nations estimates. Twenty-one cities now hold more than 10 million people, and many more will join their ranks by mid-century. Robert Kunzig, senior environment editor of National Geographic, shares his views on the impacts of the explosion and whether alarmism is warranted.  His feature on the population boom, the beginning of a year-long series on our crowded planet, appeared in the magazine this month.
The demographic tools at our disposal have presumably matured since Leeuwenhoek's estimate based on cod milt. What are the best tools we have today to measure population growth and fertility rates, and how accurate are they?

Demographers still don't have a scientific theory that would allow them to predict in advance how many babies will be born and thus how population will grow. What they have is decades' worth of data on how population actually has grown in many countries. They use those observations of the past to project the future, country by country and for the planet as a whole. The UN's global projections have been pretty accurate lately, but the farther out you go, the more uncertainty there is. So we know we're going to hit 7 billion soon. Whether there'll be 9 or 8 or 10 billion in 2050 is less certain.

If leading demographers think that concern about a global population explosion is "passé", should we worry at all? Who should be the most concerned?

I'm glad you asked that. Those demographers aren't saying that population isn't a problem—that things wouldn't be easier with fewer people, especially in certain places. They're saying that the end of the global population explosion is in sight. That globally, fertility rates are already falling much faster than anyone would have thought possible a few decades ago. And that therefore there probably isn't much that could be done—and that one would feel ethically comfortable doing—to bring the global numbers down faster. None of the demographers I talked to were against the idea of making contraception more widely available to women who wanted it. And that would be an especially good thing to do in some countries in sub-Saharan Africa or the Middle East, where fertility rates are still very high and the population is still exploding.

You make the critical points that while population matters, the way we use the Earth's resources matters even more, and there is hope in human ingenuity. What ideas or initiatives to you see as most promising in addressing the problems associated with rapid population growth and climate change?

We're talking about a decades-long project that's going to take a million ideas. Right now the global economy is based on using up fossil fuels to power our machines and make our stuff, and using up topsoil and groundwater and the fish in the sea to feed ourselves. Having more people accelerates all those processes, but the fundamental problem is finding ways to convert from an extractive economy to a renewable one.  I like to hope that what's really happening in this period is not that we're simply burning through our natural capital, but that we're slowly, haltingly, but surely investing it in the new way of doing things. If I were king, I'd help the process along by phasing in a big tax on carbon.

You write that in the world's growing slums, "the problem that needs solving is poverty and lack of infrastructure, not overpopulation." Are there such things as overpopulated cities, or only unplanned cities?

There are certainly cities that don't have the resources to support the population they have. But people choose go to cities because that seems the best option to them, maybe the best of some very bad options—which means they'd have a resource problem if they hadn't migrated to the city. So yes, speaking very broadly, I think the problems of the cities have more to do with lack of planning than with overpopulation per se.

Do you have a sense of how population change will influence immigration between countries?

Globally, it will create a strong pressure toward increased immigration—from poor countries with lots of young people looking for work, to rich countries with lots of old people.

Will the exigencies of population pressure on food production and natural resources encourage more autocratic regimes?

Food shortages, whether caused by overpopulation or not, can create crises that lead to regime change. But the new regime doesn't necessarily have to be more autocratic. Here's the real answer though: I don't know.

China and India have at times deployed coercive population control measures, as you describe. Do you know of examples of effective and humane family planning initiatives?

China and India have also had humane and effective family planning—in the Indian state of Kerala for instance. There have been lots of humane family planning initiatives. Giving women and men access to contraceptives as part of generally improved health care is a good idea and I'm all for it.  

Credits: Photo of India by Randy Olson for National Geographic.  Photo of Robert Kunzig from The Aspen Institute.