SARAH MCCAMMON, HOST:
For many young people thinking about starting a family, worries about climate change or depletion of the Earth's natural resources are often a reason for thinking twice, like Annie Platt and Ryan Holley from South Carolina.
ANNIE PLATT: It's daunting.
RYAN HOLLEY: Yeah, if we're in a climate crisis that...
PLATT: Yeah.
HOLLEY: ...Is only going to get...
PLATT: Get worse.
HOLLEY: ...Accelerate. And that's something that...
PLATT: Yeah.
HOLLEY: ...That child would have to deal with long after...
PLATT: Yeah.
HOLLEY: ...I don't have to deal with it. It's like, well there's...
PLATT: Yeah, and then their children would have to deal with it and their children after that.
MCCAMMON: Or Emma Brennan and Lauren Wright, a couple in Maryland, who wonder if their city will be livable for future generations.
UNIDENTIFIED PERSON: I feel like that's the thing we talk about a lot, just 'cause Baltimore will be underwater, potentially.
MCCAMMON: Some environmentalists and climate scientists have argued that potential parents should consider smaller families as one way of taking pressure off the environment. But other researchers argue that depopulating the planet won't actually do much to solve those challenges. One of them is Dean Spears. He's an economist at the University of Texas, Austin and coauthor of the new book, "After The Spike: Population, Progress, And The Case For People." He says having fewer children isn't the solution to the climate crisis and that birth rates have been declining for years.
DEAN SPEARS: All along, even when we were hearing these overpopulation stories, global birth rates were falling from a worldwide average around five in 1950 to 2.3 today. And in fact, 1968 was the year when the world population grew its fastest. The speed has been slowing since then. The basic reason why is that people are having fewer children. The number that matters is whether there's an average of two children in the next generation to replace two people in the last. Two-thirds of people worldwide now live in a country where the birth rate is below this two-for-two that would stabilize the population. And the U.S. is at 1.6. So pretty soon, after the whole world crosses that two-for-two threshold, global depopulation will start. But it's a path we've been on for not just decades but centuries as birth rates have been falling.
MCCAMMON: Now, you and your coauthor argue that, quote, "falling birth rates are not the answer to our world's problems," including what experts agree is the biggest environmental problem of our time, which is climate change. Why not? I mean, doesn't fewer people mean fewer carbon emissions?
SPEARS: Well, yes, humans pollute, destroy and cause environmental harm. But global depopulation starting in a few decades won't solve our important climate challenges or other environmental challenges because the timing is too slow and too late. You know, the population is a large ship slow to turn. The U.N. doesn't expect depopulation to begin until the 2080s, and that's long after urgent climate deadlines. No matter what changes in near-term birth rates, the size of the population over the coming few decades is unlikely to deviate much from this most likely course.
So we shouldn't really hope for depopulation starting six decades from now to get us off the hook for decarbonization or to let it distract us from the environmental progress we need to make today. There's no serious option other than confronting and reducing per person environmental harms, emitting less carbon per person, implementing the technologies and policy changes that will continue progress against our environmental challenges. And we need to do that long before the peak in the size of the world population.
MCCAMMON: On that note about technology and finding solutions, finding ways to pollute less and emit less, you've pointed to China as an example of a place where the population has grown, and some solutions have still been found to environmental problems like air pollution. But even with cleaner technology and regulation, carbon production in China continues to rise, and the country still faces some really significant environmental problems like industrial contamination of drinking water. Is China a success story?
SPEARS: China is a story in progress. The climate challenge and environmental challenges for the world is a story in progress. But in China - you know, in 2013, China had terrible particulate air pollution. It was known around the world as their airpocalypse (ph), on a - a 700 on a scale of air pollution from zero to 500, the U.S. embassy reported. And, you know, over the decade after 2013, the size of the Chinese population grew by 50 million people. And so if more people were always worse for the environment, you might think that particle air pollution in China would have gotten worse. But, in fact, particle air pollution in China fell by half, even while the population grew.
And for the world as a whole, particulate air pollution has been falling even as the population grew - not everywhere, not, for example, in India, but importantly, in China. And, you know, how did it do it? Well, by enforcing regulation, by implementing new technologies and shutting down coal plants - by deciding to clear the air by changing what people do.
MCCAMMON: But don't more people arguably also mean - to put it sort of crassly - more potential problems. I mean, you've more brilliant thinkers but also more consumers of resources and more people producing pollution. Explain why more people necessarily equals a net gain when it comes to solving big problems.
SPEARS: A surprising part of this, just as you ask, is that other people are good for us even when they're wanting and needing things, even when they're on the demand side of the economy because other people wanting and needing what you want and need is part of how and why you get it. That's why rare diseases are less likely to have good medical treatments, for example. No one can - it's not feasible to do the sort of research to find cures if there aren't enough people who need it.
And, you know, that's why something like public radio has important scale effects. So public radio, like, you know, new vaccine recipes or like cures for new diseases, has this important property where once you have something, many, many people can use it. But if there aren't enough people who need it or want it or demand it, then it might never exist in the first place. So in a depopulating future, less public goods, innovation and health care will be feasible, and it'll be harder to continue to make progress against poverty and disease and towards better living standards.
MCCAMMON: And I just feel like I need to say that we did not put you up to using that example.
SPEARS: (Laughter).
MCCAMMON: I feel like I hear in some of your comments almost a worry that we've collectively become too negative about children and about the future. Is that fair?
SPEARS: Well, one of the things that we've definitely done is haven't done a good enough job sharing the burdens and costs of creating the next generation. We've created a society where we - you know, some people do important work, and some people do care work. And frankly, we put a lot of the burden of parenting on women, and so it's no surprise when a lot of people choose not to do it. You know, we're not here to say - I'm not here to say that anybody's making a mistake when they look at the world as it is and decide not to or decide to have children. But we might all be making a mistake together if we're not looking ahead to building a future where parenting is fairer and more feasible, and so more people who want to be parents can choose to be.
MCCAMMON: Dean Spears is an economist at the University of Texas Austin and the coauthor of the new book "After The Spike: Population, Progress, And The Case For People." Thanks so much for being with us.
SPEARS: Thanks for having me. Transcript provided by NPR, Copyright NPR.
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