7 Billion And Counting: Can Earth Handle It? The planet's population stands at nearly 7 billion, and demographers project we may reach 9 billion by the middle of this century. Already, forests are vanishing, glaciers are melting and almost 1 billion people go hungry each day. When experts look to a world with 2 billion more people, they see India as a vision of that future.

7 Billion And Counting: Can Earth Handle It?

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NEAL CONAN, Host:

This is TALK OF THE NATION. I'm Neal Conan broadcasting, today, from the Grosvenor Auditorium at National Geographic in Washington, D.C.

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CONAN: Seven billion people will inhabit the Earth by the end of this year, a number that's difficult to fathom. Over the past 50 years, our numbers have grown at a clip never before seen in the course of human history.

Farmlands became towns, cities mushroomed into megatropolises, and humanity now occupies once-remote places, to the extent that some scientists now refer to this as the Age of Man.

And all this change comes as glaciers melt, forests dwindle, many species struggle to survive, and millions of people go hungry every day and live without clean water.

TALK OF THE NATION: 800-989-8255 is the phone number. The email address, talk@npr.org. You can join the conversation on our website. That's at npr.org. Click on TALK OF THE NATION. We'll also take questions from members of the audience here at the Grosvenor Auditorium.

Joining me on stage is Robert Kunzig senior editor for the environment for National Geographic magazine, author of the January issue's cover story. Nice to have you with us today.

ROBERT KUNZIG: Nice to be here, thank you.

CONAN: And your article is filled with amazing charts and graphs and numbers and statistics. Is there one place you visited for this story that emblemizes for you the growth of population?

KUNZIG: I guess that would have to be India. I spent a few weeks there researching the story, and there's really no place like India to get the experience of being immersed in a crowd.

You - most Western visitors have the same experience of leaving their little hotel oasis and getting hit by a brick of heat and dust and just the people everywhere.

CONAN: Any particular place in India?

KUNZIG: Well, I spent - I went to two very different places, and that's something that I think people are not aware of, just how - or people over here, anyway - just how complex India is - India's population is.

I went to the south of India, where population growth has really been arrested. And then I spent some time In Delhi, and that's a very different story. Delhi is growing. It's a typical developing-country, megacity, 20 million people, people streaming in every day.

CONAN: Describe one of the - there are many places where people stream in. Of course, there's no sewage or housing or water ready for them.

KUNZIG: No, there really isn't. They - it's - the government tries to plan, but it's really just sort of overwhelmed by events. So people make their own way. And there are outright slums that are shantytowns.

But then we visited a neighborhood that was something different. It was - you would call it a lower-middle-class neighborhood, I guess, but people are actually building their own apartment buildings and making their way, stealing electricity from the electric company.

So it's just - it's a hodgepodge of worlds, cows in the streets, satellite dishes on the roofs.

CONAN: And that sounds like it is a recipe for gloom.

KUNZIG: It is, in some sense, but it's also something more. There's just a tremendous energy there that I found very hopeful. I met people in that neighborhood I was telling you about, on the other side of the Yamuna River, from the center of town, that are just - that have come in from the countryside, have built their own homes and are now devoting themselves to the education of their children.

And I just - I felt the energy is actually - to me, it gave me more optimism than not.

CONAN: Interesting, also, if those children are educated, especially the girls, demographers suggest they will have fewer children, many fewer children, than their mothers did.

KUNZIG: That's exactly right, and that's the pattern in India today. As I said before, in large parts of India, women are already having what's called below-replacement fertility. They're not having two kids, basically. So in time, that means the population will stabilize.

And in that southern state of Kerala that I went to, that has been the key. The literacy rate of girls is one of the best predictors of future fertility.

CONAN: Robert Kunzig's cover article in this week's, this month's National Geographic, says, well, we'll be seven billion by the end of this year. The bad news is we will be nine billion by mid-century. But the demographers expect population at that point to be leveling off and a very different shape to that population than the one you might expect.

More on that later, but let's get some questions in. We'll start here in the audience at the Grosvenor Auditorium. Is this Amelia(ph)?

AMELIA: Yes.

CONAN: Go ahead.

AMELIA: I'm from College Park, Maryland, and why are there more people listening - or why are there more people living in cities than rural areas?

CONAN: Well, that was one of the charts that you demonstrated in the magazine, as people move from rural areas into cities, but why, Rob?

KUNZIG: I guess the first answer is that life in rural areas is very hard. And when people get a chance to move on to a different life and city and get a job there, they often take it.

In India, we went to a place where just that was happening, where people - subsistence farmers are living in a place with no plumbing, no electricity and so on.

So you visit places like that, and you see the appeal even of some of those not-so-luxurious neighborhoods in Delhi.

CONAN: As tough as those neighborhoods are, they are better than the places that those people left.

KUNZIG: That's right.

CONAN: Let's bring another voice into the conversation. With us onstage, also at the Grosvenor Auditorium, is NPR science correspondent Richard Harris, and Richard, always nice to have you with us.

RICHARD HARRIS: Great to be here, Neal, thanks.

CONAN: And this is all going on, as we mentioned, amid climate change, and climate change is going to be affected not just by the previous effects on the Earth's atmosphere but by the effects all of these people are going to have on the Earth's atmosphere.

HARRIS: That's absolutely true, and it's not just numbers of people, but it's how they use energy that really matters. Most - I mean, when you look at it, we in the United States are about five percent of the world's population, but we are responsible for something like 20 percent, more than 20 percent of the world's emissions.

So it's not just body counts. It's our lifestyles and how much resources we can consume. So there are two trends going on, and some people think population is maybe even the less important of the trends at least in the short run, but clearly both are playing a big role.

And of course, as populations grow, and as places develop better ability to live the lifestyle that we like to live, of course then they start consuming more energy, too. So even though today we, you know, we're sort of off the charts in the amount of energy we consume, the truth is that most people around the world would like to be where we are. So...

CONAN: And as those people, perversely, as places like India succeed and develop more of a middle class, they're going to want to drive cars and eat meat and do a lot of the things, as you mentioned, that we in the West do. And of course, those are very intensive in terms of the carbon footprint and then accelerate climate change.

HARRIS: Right, and then let's not forget that if you have more people on Earth, you also need to be able to feed them better, which means that you need to develop agriculture. I mean, it's - and emissions increase as a result of that, as well.

So it's - it works both directions, that population feeds energy needs energy needs make the planet more uncomfortable and in some places more difficult to grow crops, and so yeah, we're heading towards an uncomfortable future if we continue on this current trend.

CONAN: Let's go to - I'm sorry, Rob, you were going to say?

KUNZIG: Yeah, if I could just jump in there. I mean, I think the key thing to think about there is all these problems that Richard mentioned, the - chiefly among them the energy problem, are problems we're going to have to solve anyway, no matter what the population level.

So one of the reasons we decided to do this series at National Geographic was because we get so much mail from our readers, telling us, you know, why aren't you tackling population. It's the real problem, the fundamental problem.

But when you look at it more closely, it isn't really the best way to get at all of these real environmental problems like energy, like how do we save the oceans, prevent deforestation, all of that stuff. All of those things have to be tackled whether we're eight billion people on Earth or seven or nine, and the scale of them is large in any case.

So in terms of a strategy for surviving on Earth, focusing on the number of people is really not the wisest one. That was what I was trying to get across in the article.

CONAN: Let's get another question from here in the audience at Jim Grosvenor Auditorium.

KAYLA: I'm Kayla, and I'm also from College Park. I was wondering if the population was going to be nine billion 2045, how many babies would the average person have??

KUNZIG: Well, according to the projections of the United Nations, by about 2035, the average woman on Earth will be having only two babies. And so at that point, that's the level that you have to have for population to be stable, and population will keep growing after that for a little while under its own momentum.

By 2045, something less than two babies is what people imagine, 1.8 baby per woman. How they're going to manage that, I'm not sure...

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KUNZIG: But these are averages.

CONAN: It's interesting. You were in India, you mentioned, for the story for Geographic. One of the places you visited was a vasectomy clinic where men are paid a fee, I think adding up to about $25, to have a vasectomy.

KUNZIG: Yeah, the government has started encouraging this again. There was a long period where they didn't dare because there were some really kind of sordid experiences in India in the '70s with people being coerced into being sterilized.

But now what they're doing is they're offering essentially, it's 1,100 rupee payments to men who will get a vasectomy. It's about a week's wages. It's much easier and less risk than sterilizing a woman, which is still - which is the dominant form of birth control in India.

CONAN: Let's see if we can get a caller in on the conversation, and let's go to Gorub(ph), Gorub with us from Detroit.

GORUB: Hi, how are you doing?

CONAN: Very well, thanks.

GORUB: I apologize for the connection. Thanks for taking my call. I am a doctor from India, grew up in India in some of the most rural settings that you can imagine and lived in the city, was educated in the city.

But I just wanted to give you a perspective on India. It's been a mixing pot of cultures from - for a long, long time, which has led to a huge, diverse population with very different belief systems with varying levels of education, which have been big stumbling blocks in all these programs that you've been talking about, like the vasectomy clinics.

And none of them has really proven to be successful, whether it be government- run or NGO-supported programs for population control. And that has led to a huge problem, where people are migrating from rural areas into these cities and suffer a total lack of support infrastructure, be it electricity, sanitation, health care, housing, which results in these wide disparities you see in the urban landscape.

CONAN: And indeed in Robert Kunzig's article in the National Geographic, he talks about how, in fact, the upper and middle classes in India are already below replacement level in terms of the number of babies born, while some of the lower classes are still well above, and, yes, there are all those disparities. Thanks very much for the call and for your perspective.

We're talking about the two billion people we expect to add to the world population in coming decades. Stay with us. It's the TALK OF THE NATION from NPR News.

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CONAN: This is TALK OF THE NATION from NPR News. I'm Neal Conan broadcasting today from the headquarters of National Geographic here in Washington, D.C.

The January cover story of National Geographic magazine, "7 Billion" is the title, roughly the number of people on Earth right now. The population continues to climb, though more slowly than in recent decades.

Our focus today on the challenges feeding, housing, employing, caring for the billions more people on Earth that demographers expect in coming years. The magazine includes a number of dramatic photographs that tell the story of population growth around the world. We've put many of them together in a slideshow at our website. That's at npr.org. Just click on TALK OF THE NATION.

We want to hear from those of you who have seen the effects of population growth firsthand, especially those who've worked or lived overseas, 800-989- 8255. Email us, talk@npr.org. You can also join the conversation on that aforementioned website. That's at npr.org. Again, click on TALK OF THE NATION.

Our guests here at the Grosvenor Auditorium, Robert Kunzig, senior editor for the environment at National Geographic. He is the author of this month's cover story on world population. Also, NPR science correspondent Richard Harris.

Let's see if we can get another caller in on the conversation, and let's go to Duke(ph), and Duke is with us from Denali in Alaska.

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DUKE: Hi, there. I'm actually calling from Ohio. I'm on a trip right now. But I had a question for the panel. What kind of effects do they see on population shifts from people moving out of places like, say, Phoenix, Arizona, where they may be experiencing drought soon, to places, and I've heard this, of people becoming more interested in areas up in Alaska, where, you know, global warming and such might be changing the naturally harsh winters up there and people becoming more interested in property up there.

CONAN: Duke, do you live in Alaska normally?

DUKE: I work there in the field seasons, yes, for the summers.

CONAN: A long commute from Ohio.

DUKE: It is. It's a long drive.

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CONAN: Richard Harris, how about you can help us out with that?

HARRIS: Yeah, well, I think that the first thing people are hoping in the Southwest is that somebody else will solve their water shortage problems for them because that is one of the major projections about climate change is that the droughts that strike the Southwest are going to become essentially permanent.

And there are some things you can do to use water more wisely and to make do with what you have. But I think that they - and they're starting to think about that in the Southwest but not to say that they have solved those problems. I think that it will be a long time before snowbirds will consider Alaska a warm destination.

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HARRIS: If you look at projections of global warming, I mean, it is true that the poles are warming much faster than the rest of the planet, but on the other hand, they have a lot farther to go before you start to get to those Phoenix- like temperatures.

So I think - I'm sure that there are some people who are thinking about that, but I suspect that the snowbirds will continue to fly south.

DUKE: Maybe it's a bit of paranoia involved in that.

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CONAN: Duke, thanks very much for the phone call, appreciate it.

DUKE: Thank you.

CONAN: Speaking of the water situation, joining us now from our bureau in New York is Upmanu Lall, director of the Water Center at Columbia University, a senior research scientist for International Research Institute for Climate and Society. Nice to have you with us today.

UPMANU LALL: Thank you, Neal. It's a pleasure to be with you and Robert and Richard.

CONAN: You're originally from India, where many people, as in other countries, grapple with water shortages. What did you experience in terms of the effects of population? Was access to water an issue for your family growing up?

LALL: Not really in the sense that it has become today. I came to the United States in 1977, and at that time, things were - the main issue was whether or not infrastructure was available to deliver water to the population that you were part of.

Today, the situation has changed dramatically, where it's no longer a question of infrastructure. The government has actually managed to make significant inroads in that direction. The question today is one where the resource itself has become significantly depleted in many parts of the country.

Delhi, which Robert talks about, has 22 million people and it has one of the larger rivers in India flowing by it call, called the Yamuna. This river is now essentially a sewer over most of the year. And the surrounding area has seen significant groundwater depletion, partly because of Delhi's use but partly also because of agricultural pumping.

And some of you who've probably heard stories of the detection by the GRACE satellite have heard that in parts of India, you can now see significant amounts of water from fossil groundwater aquifers that have been removed that can be seen from space. It's the largest mining operation in the world.

CONAN: Well, you see that, that's the mega-picture. What about the individual picture? Your family in India, how many hours a day do they have water available?

LALL: Right. So when I was growing up, I lived in, at least in the last seven or eight years of growing up in India, I lived in a town called Chandigarh, which was designed by Le Corbusier, a French architect, and it was built as a temple of modern India under the direction of the Prime Minister Nehru.

So that was very different from the rest of India. We had water supplies that were 24/7 and offer quality comparable to Western standards. In fact, the main complaint people would have had in those days was if you turned on the faucet, you got a blast of chlorine.

Today, there's two hours of supply on a daily basis, an hour in the morning, an hour in the evening. And this is in part due to the increased population in the area and restrictions to meet their needs and in part because, given the depletion in groundwater in the surrounding area, the cost of pumping has gone up, and the municipality just don't want to run the pumps.

CONAN: All right, well, let's get another question from here in the audience at the Grosvenor Auditorium.

SARA: Hi, I'm Sara(ph) from Johns Hopkins SAIS in Washington, D.C., and I'm just wondering, when the population does reach nine billion, what will happen to the stratification between the developed and the developing world in terms of quality of life, et cetera?

CONAN: Well, Robert Kunzig, that goes to where these new people are going to be.

KUNZIG: Yeah, the growth is actually almost, in the next 30 or 40 years, is really a developing country phenomenon. The population is going to be growing in developing-country cities because we're going through this - we're going through two huge transitions at the same time, a population boom, which is going to slowly come to an end, and an urban boom, because all over the world, people are doing the same thing that we already did in the U.S. and Europe, moving to cities.

So what was your question again?

CONAN: How is this boom and these dwindling resources going to affect the stratification of society?

KUNZIG: Right. Well, that's a very interesting question because we tend to think of countries as locked in certain categories, that developing countries today are going to be still developing then.

The fact is, they're - the economic growth in places like India and China is huge. And at the moment, I would say population - thinking on my feet here - the population boom has, if anything, been helpful to evening out the stratification because countries like China and India have an enormous young population at the moment.

And so they're benefiting from what demographers call the demographic dividend. They have a lot of people working, few kids and old people to support. And so that's one of the reasons that their economics have been booming and that they're catching up fairly rapidly in terms of income, also in terms of energy use and resource use, as Richard said.

CONAN: Let me ask you, Upmanu Lall, as India eventually overtakes China, that's part of the projection, in terms of population, in terms of your expertise, water resources, is there any way they're going to be able to cope with this? And of course, if they're not, that's going to fall mostly on the lower classes.

LALL: Yes, this - I'm not nearly as optimistic as Robert about the future of India with regard to resources, especially water resources but also land resources.

The biggest challenge is one of meeting the food needs of all these people. And things have - you know, it's a dramatic story, in a sense. When I was young, in the '60s, if there was a drought, we stood in lines for days on end to get food at controlled prices from government shops. Today, that situation doesn't exist. India periodically actually exports food.

But this progress has come at the price of dramatic extraction of water and of dramatic utilization of land and a degradation of the soil. And we are also looking at a situation where phosphorous, which has been one of the key ingredients in increasing productivity, is starting to run out, in terms of the future.

So if we look at it from that perspective, it doesn't look so good. The government structures in India and the ability to do things don't look so good. On the other hand, India is an enigma. Despite all the chaos, somehow things actually work.

So the fact that the population has nearly tripled since I was a kid, and things are better, gives hope for optimism.

CONAN: And Richard, one of the things that has happened is we have innovated our way out of several projected crises in the past. And indeed, India once projected to be in desperate straits, as we've just heard now, a net exporter of food.

HARRIS: That's right. And the question is, are there, you know, are - can we keep doing that, particularly with food production? I mean, when we turned our attention to the green revolution, other technologies, obviously we were able to feed a lot more mouths than we were before. The question is, can we keep doing that? I mean, it's - unfortunately it's not like microchips, where you can just keep, you know, doubling their capacity every 18 months. These are harder challenges, and they sometimes involve controversial issues like do you start - to what extent do you genetically engineer crops and so on.

So, yes, obviously there's going to need to be tremendous innovation, not only in agriculture but clearly in energy if you're - if we're going to not essentially bake the planet in the process of watching places like India and China and the rest of the world that is, you know, that does not have all the luxuries that we have, come up and join us without putting so much carbon dioxide into the atmosphere.

CONAN: Well, let's go to another question here in the audience in Washington, D.C.

SONIA: Hi, I'm Sonia, also from the Johns Hopkins School of Advanced International Studies. My question is, if you had to pick three technological innovations - past, present or future - critical to alleviating the burdens of overpopulation, what would they be?

CONAN: Hmm.

HARRIS: Well, I think that - I keep coming back to climate just because I think it's in the long run going to be the biggest issue for us. So I think the technology that I would put number one on that list would be finding ways to generate energy without putting carbon dioxide into the atmosphere and doing it cheaply, so it's - so there's an economic incentive to switch from burning fossil fuels to that, and that's tricky.

I also alluded to the agricultural technologies, so that you can make better use of land. I mean clearly there's a lot of agriculture that's not working at the standards that we've grown accustomed to in this country, so you can just apply some of the technologies that already exist around the world and help. But I think that - that that's going to work for only so long. And Rob may have a third one.

KUNZIG: Well...

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KUNZIG: ...since you offered the possibility of talking about past innovations, I would say that, in fact, discovering oil and discovering chemical fertilizers was absolutely critical to making it possible for us all to be alive today. And so - and they are now presenting us huge problems, the side effects, that no one imagined at the time, but they were not in themselves intrinsically bad things. We've gotten tremendous gain out of it.

And so the question really for us now is, are we going to use this period when we've basically been taking resources from the planet, a whole series of them - fossil fuels, soil, forests - and using them and wasting them, are we going to have used that as a period of investment in these new technologies that will allow us to get to a new way of doing things, where we are doing things in cycles rather than one-way extraction? But I'd say the jury is still out. Those past inventions have been great for allowing humans to survive on Earth, and we've got to get past them(ph).

CONAN: That is Robert Kunzig, National Geographic's senior editor for the environment. Also with us on stage here on the Grosvenor Auditorium, Richard Harris, NPR's science correspondent. With us from our bureau in New York is Upmanu Lall, director of the Water Center at Columbia University. You're listening to TALK OF THE NATION from NPR News.

And this email from Patrick in Minnesota. He says - well, the good news, he says, finally a subject that covers almost all the world's current problems. Now the bad news. I disagree with the guests that population is not crucial in healthy living on Earth. Every other species has ways to curb population to balance ecosystems. So Rob, I guess that's to you.

KUNZIG: I'm glad we're not like every other species.

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KUNZIG: We're intelligent. We can do better, and I do not believe that even at nine billion we are anywhere near the biological limit of humans surviving on Earth. That's just not the issue, in my opinion.

CONAN: Following up, this email from Don in Alamosa, Colorado: All the problems you speak of would be more easily solved with a smaller population. If that's true, why not the first problem to be solved, that of population?

I wonder, Richard, you were just at the Cancun conference. Was population discussed there?

HARRIS: Population is generally not discussed in these climate talks, and this really does get back to something Rob said earlier, which is that basically you have to have a solution that will work for seven people - seven billion people as well as for nine billion people, so you have to focus on the solution regardless of how many people are on Earth. And it is - you know, I think that in the long run you do have to worry about...

CONAN: It does matter whether there is seven or nine billion.

HARRIS: It does. Yeah. And I always fantasize about what if people were smaller, would we - how 'bout that?

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HARRIS: Maybe...

CONAN: That species that was discovered in Indonesia - if they had conquered the world. Yeah.

HARRIS: Yeah, the so-called hobbit.

CONAN: Yes.

HARRIS: Yeah. We'd use comparatively fewer resources. But no, I think that in the long run we have to deal with this issue. I think what we've also seen is as technology develops and as people have an expectation that their children are going to grow up to be adults, that people take care of this issue. They have fewer babies and world population will stabilize. I mean, a major reason, I think, that there's still overpopulation in places like Niger in West Africa is that many children die, and so parents say if I want to have enough kids to make sure that a few of them are going to survive to support me in my old age, I need to have a bunch of kids. And I think that - so some of these problems are self-correcting, and I think that that's been very much the viewpoint of the United Nations when it comes to climate and other issues about population. So you don't have to impose, you know, prescriptive policies for population growth. But basically if you can help people develop a nice - a comfortable lifestyle and give them the access to medical care and so on, they can do it themselves.

CONAN: Upmanu Lall, given the water resources in India, is it a question of sheer numbers of people, or is it better uses of resources and policy?

LALL: When people were talking earlier, I was going to say you could have a lot of minnows or few large fish. You know, so there is that sort of aspect to this story. But the general situation is that India does not have very efficient agriculture compared to many other places. On the other hand, they have multiple crops per year. So if you look at annual productivity per unit land, it may not be so bad - as all the conservation strategies and efficiency improvement strategies allow you to bring a situation that is out of kilter into balance. But once you do that, there's no further opportunity going in that direction. So the challenge, I think, for India is that if they continue to grow and - they will, of course, have to improve practices. But after that, what?

CONAN: Upmanu Lall with us from our bureau in New York, director of the Water Center at Columbia University, a professor of engineering there as well. Also with us here at the Grosvenor Auditorium in downtown Washington, D.C., at the National Geographic Society, Richard Harris, NPR science correspondent, and Robert Kunzig, National Geographic's senior editor for the environment and author of the geographic magazine's January cover story on world population, "7 Billion."

More of your calls in a minute. What effects of population growth have you seen? 800-989-8255. Email us, talk@npr.org. Stay with us. I'm Neal Conan. It's the TALK OF THE NATION from NPR News.

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CONAN: Right now we're talking about the world's population, nearly seven billion now and counting. The growth is mostly in poorer countries, and it affects everything from climate to health care. We want to hear from those of you who've seen the effects of population growth, especially those who worked or lived overseas. 800-989-8255. You can also reach us by email. The address is talk@npr.org. And there's our website as well. You can contact us there. Go to npr.org. Click on TALK OF THE NATION.

Our guests here at the headquarters of National Geographic are Rob Kunzig, senior editor for the environment at National Geographic. He wrote January's cover story on world population. There's a link to that at our website. And also science correspondent Richard Harris. With us from New York is Upmanu Lall, who directs the Water Center at Columbia University and serves as a senior research scientist for the International Research Institute for Climate and Society.

And let's get another question from here in the audience at the Grosvenor Auditorium.

JULIAN: Hi, I'm Julian, and from - I'm from - I'm in eighth grade from Friends Community School. And if the resources are going to run out, what can we kids do about it?

CONAN: Well, Rob, I'm going to throw that to you. You wrote the big article.

(SOUNDBITE OF LAUGHTER)

KUNZIG: Thank you very much. Well...

(SOUNDBITE OF LAUGHTER)

KUNZIG: Stay in school.

(SOUNDBITE OF LAUGHTER)

KUNZIG: You know. Get a good job and make some great invention that's going to help out. I mean, that's the best thing.

(SOUNDBITE OF LAUGHTER)

HARRIS: If I could chime in, I actually don't think resources are actually going to run out.

KUNZIG: Yeah.

HARRIS: I think that's the good news. We just have to be smarter about how we manage them, and that really is the important thing for us to think about looking forward, is - I mean so much energy comes to us from the sun. Let's find a better way to use that energy on Earth. So when fossil fuels become scarce, we have something else we can use for energy. So there are all sorts of solutions, and that's what - you know, it's exciting to look at young people and say, okay, you're going to have to solve the problems that we're creating right now. Sorry about that. But you know, fortunately, there are a lot of smart kids out there and - but it's good. You have to have start thinking about those problems now.

CONAN: Let's see if we go next to a caller. This is Dave, and Dave with us from Banner in Wyoming.

DAVE: Hello.

CONAN: Hi, go ahead.

DAVE: Well, thank you very much for taking my call. My question is there's not a politician alive in the world that would touch the issue of religion and population. And (technical difficulties) address that.

CONAN: The role of religion. And it was interesting, Rob, as you were going through your article, the world population continues to drop in almost all areas of the world, seemingly regardless of religion.

KUNZIG: Yes. I'm sorry. I'm thinking now whether this journalist alive wants to address religion in this time and place. But I think religious beliefs do make a big difference. And I would say in general, the belief that whether we give birth or whether we die is a matter for we humans to deicide, or whether it is a matter that is exclusively in God's hands is a sort of a critical transition that countries - that countries have gone through it at different times, and in...

CONAN: Generally we refer to it in the West as the Enlightenment.

KUNZIG: The Enlightenment, yes, right. And for instance, it's one of the things that I learned as I was researching this and talking to French demographers about the history there - France went through the fertility transition. That is, women stopped having as many babies as they possibly could earlier than almost anywhere else, and it's associated with this - it was that change in mindset that allowed them to think of it as a question that was for them to decide. That has to happen. It can't just be act of fate or else that fertility transition will never happen.

CONAN: One of the things the demographers in your story said would be critical to deciding the fate of the Earth, no less, was if there were clinics available for women to attend and find out more about reproduction.

KUNZIG: Well, that's - you need both. You need the birth-control methods to be available, and you need the people to have the mindset that allows them to want to use them.

CONAN: Email in this regard. I just wanted to follow up. This is from Tim in Cincinnati. People in the West continue to live longer due to medical advances. How does longevity figure into the 20/35 population projection. I think he meant 20/45, but - got the right number.

KUNZIG: Yeah. Well, longevity - the medical advance, that's a very good question, because the reason the population boom happened in the first place - and I think it's really important to understand this because it affect how you think about it - is that we found a way to conquer death, basically. We - people stopped...

CONAN: Really?

KUNZIG: Yes.

CONAN: We have big news today.

KUNZIG: Well, I'm breaking it right here on your show, Neal. It - people - because of increases in life span - and it happened extremely rapidly in developing countries after World War II. So, India, for instance, has seen a 25-year increase in life span since the '40s. China, it's even greater. And that - and so kids who would have died grew up to have children themselves - as a result of medical advance.

CONAN: And sanitation, yeah.

KUNZIG: So - and as far as the future, well, the future, worldwide, we're looking at a much older population. It's already happening in the West again. But the global average age is increasing steadily. And, yes, as people live longer, that is one of the reasons for population growth.

CONAN: And that's why you can see projections down the line. Japan's population, elderly by world standards, there were fewer people working there to support people who are grey, than, I think, anywhere else in the world. Yet, as you look at the results of China's one child policy down the road, the same situation is going to apply there.

KUNZIG: It is - it's going to apply and, in a way, in a more extreme way. China is a fascinating case. They attempted to reduce their population absolutely as fast as possible. They implemented a policy designed by a rocket scientist who thought he could manage population like a rocket, quite literally, by calculating the optimum trajectory and then devising a policy, their one child policy, to bring it about. And the result, in a decade or two, is going to be a demographic crash, even more extreme than what we're experiencing here. They're going to have a lot of old people, relatively fast. And they're going to have to figure out their social security problem just as we are facing, but only with less time.

CONAN: And let's see if - our debate may be over by then. Let's go to Will and Will is with us from Boston.

WILL: Hi. I wanted to ask - I'm from Puerto Rico. It's a small island in the Caribbean. We have this issue in Puerto Rico that, as economy becomes to slow down, a lot of people migrate to the U.S. And, you know, because we don't have - we have that relationship with the U.S., we don't have a problem of borders. And I wanted to ask, how would you see the change in border policy for countries in - you know, in the first world - change due to the population growth?

CONAN: Richard, that's a fascinating question, because, you see, borders set up on the theory that - well, Poland for the Poles, France for the French, America for the Americans - peoples continue to move. And perhaps, given climate change, and Puerto Rico is one example, even more rapidly than before.

KUNZIG: That's true. But I also think this gets back to something we're talking about at the beginning of this program, which is it's not necessarily the population growth that's the pressure. It's the economic differences. If people want to move to places where they have more economic opportunities. And so I think that that's really the driving force and what we're seeing, clearly, with many of the border disputes around the world.

CONAN: Upmanu Lall, this is something that is illustrated in many cases by India. We were talking before about people moving from places - well, it doesn't seem like a great opportunity to move to a slum in Delhi, but it is better than the rural life that those people had.

LALL: Yes. I think the part that is not as well understood, is the role played by gradients. Differences of resource availability in time, differences of resource availability in space. And this is true of both financial resources and natural resources, because those are the gradients that actually drive motions of people and also conflict.

The case with India is interesting, because it's not just the rural to urban migration that's interesting here. What we find is that there's about 50 million people a year who are doing rural to rural migration in India, looking for employment opportunities purely in the rural sector, which are more enumerative than what we get their own location.

The funny thing about this is that they typically go from places which are resource-rich, as far as water is concern, to places that are resource-poor, such as the Punjab or into Andhra Pradesh. And essentially, they're going to go pump water to grow rice, which is then exported back to where they came from.

(SOUNDBITE OF LAUGHTER)

LALL: This is very interesting, how it emerges. And it's partly the social structure and partly the availability of technologies, and partly the land tenure situation that provide the gradients that lead to that particular outcome.

CONAN: Right. Will, thanks very much for the phone call. Let's see if we can go next to - this is Grace, Grace with us from Philly.

GRACE: Hi. How are you?

CONAN: Very well. Thank you.

GRACE: I have more like a statement or maybe, I guess, like a suggestion. I'm from - originally from Nairobi, Kenya, East Africa. And we do have a lot of rural/urban migration. And we have all the slums all over the place because we don't have enough and affordable housing to accommodate the people from the countryside. So I was wondering, if we - if a lot of developing countries focus their resources on developing the rural, you know, cities and areas like that and created infrastructure that would provide jobs for them, would that reduce the amount of people moving the cities and reduce the amount of problems for the cities?

And also, maybe, obviously, if we improve the infrastructure and business opportunities for the people in the countryside, then they will be educated as well and therefore not have as many children. Suggestion, maybe?

CONAN: Rob Kunzig?

KUNZIG: I just want to heartily agree with that. And I think in India, you'll find people telling you the same thing. The reaction to this migration from farm to city is often to say, well, we've got to - there are too many people in rural areas. But actually, what we need to do is improve their situation. They - if they were - if getting along were easier in these places, they would be less inclined to leave.

CONAN: Improve life in villages, one of the conclusions...

KUNZIG: Right.

CONAN: ...in your piece, yeah.

KUNZIG: Yes.

HARRIS: You know, I saw this happening in Haiti right after earthquake, as a matter of fact. One of the big strategies for dealing with all of these - more than million people homeless in Port-au-Prince - was to encourage people to go back to the rural countryside. And I actually spent a day going out to the countryside to find somebody who had gone home to her - to, you know, where her parents were and so on. And she was really unhappy. There was nothing there for her.

And so, even under really desperate circumstances like an enormous earthquake like that, this policy - and when people are really forced because their homes have been destroyed, they're just anxious as it can be to get back to the city because they just find so little to do in the countryside and so little economic opportunity.

CONAN: Grace, thanks very much for the call. That was Richard Harris, NPR science correspondent. Also with us, Rob Kunzig, National Geographic senior editor for the environment. And with us from our bureau in New York, Upmanu Lall, senior research scientist for the International Research Institute for climate and society. You're listening to TALK OF THE NATION from NPR News. And let's get another question here in the auditorium.

SABRINA: Hello. I'm Sabrina from Northern Virginia. How will food production shift in the future? Will we continue to move to organic versus mass production?

CONAN: Well, Richard, I'm going to throw that to you.

HARRIS: Okay. Well, I think that we should put the organic movement into perspective, which is that there are a small segment of the population very enthusiastic about organic. But it's still a very small percentage of our food production. And I don't think we're going to see a wholesale shift to that anytime in the near future. It's so much less expensive to do conventional agriculture. And you can make improvements and so on.

So I don't see a huge ship there, but I think there's going to be that niche. From what I can tell, it's likely to grow. And as people, like you and I, who have a lot of disposable income and don't mind the small difference in price to pay for organic or locally grown food, I think that we'll certainly see that trend continuing. But it's not - it's still very small compared to agricultural production as a whole.

CONAN: Here's an email, and this is from Deirdre. Every single environmental problem described in National Geographic is exacerbated or directly caused by population growth, overpopulation and population pressure. It is ludicrous to think it is not central to solving these problems. I live on a farm in Maryland. I see the effects every day: far fewer birds, inability to see the stars, unpredictable weather, traffic jams, wells going dry. For the first time in the farm's history, far fewer species of any kind, other than humans. What about beauty? What about nature? Are we the only interested in feeding mouths? Why is no one interested in talking about this? And Rob Kunzig, I think she's...

KUNZIG: Sounds like a question for Richard, absolutely.

HARRIS: Well, you take this one.

(SOUNDBITE OF LAUGHTER)

KUNZIG: Apparently, I was not entirely convincing. But, I understand that perspective completely. Listen, I live in Northern Virginia right now. I live in a house that my parents bought in the 1960s. And when I was there as a boy, I looked out over a road, it was the Dulles Road, but it was - there was no traffic on it. And beyond, there were wooded hills. Now, I look out the window, I'm looking at the likes of Tysons Corner. There's a whole new city there. The horse farms are gone. I don't like that change much. But the question is what are you going to do about it? I mean, and is really, what can you do about it? If we're looking at the global situation, yes, more people are more mouths to feed. More people use more energy. But the fertility rate is already falling very fast.

Demographers are shocked by how rapidly the change that took us, here in the West, a century and a half, is happening now in India and China. So what - where is the best place to focus our energy? That's what I'm trying to say. And I don't think it's on some sort of crash program of population control. I'm not trying to be Pollyanna and say the numbers don't matter - they do matter. But the question is what should we be focusing on? Should we be anxious about the numbers or should we be just trying to solve all the problems that we have to solve anyway? That's the argument.

CONAN: And Richard Harris, just to put your feet into this hot water, isn't climate change going to be reducing some of those numbers for us?

HARRIS: I think that that's a fairly extreme possibility. I think that - certainly, there are catastrophic - if you're talking about the next - in this century, there are some possibilities of really catastrophic happenings. But I think that people are realizing that some change is inevitable, and they're starting to think about how we need to adapt to it. And I think that certainly the wealthy parts of the world have figured out that by and large, we can adapt to these things. And there's enough wealth in the developing world, as well - yes, I think that they'll be able to adapt as well. But it's not a foregone conclusion that we are going to suffer a catastrophe, at least not in this century.

CONAN: Upmanu Lall is going to be glad to hear that we're running out of time, so I'm not going to be able to throw a version of this to him. But we do thank him for his time today. We appreciate your coming in today, sir.

LALL: Okay. Thank you.

CONAN: Upmanu Lall, director of the Water Center at Columbia University. Our thanks as well to Robert Kunzig of National Geographic, where he's senior editor for the environment, author of the January cover story on world population, "7 Billion." And NPR science correspondent Richard Harris. Our thanks to everybody here at Geographic, our studio audience, the staff and the technical crew at the Grosvenor Auditorium and back in Studio 3A. This is TALK OF THE NATION from NPR News.

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