Technology isn’t going to fix this problem, Weisman found. And though the book’s subtitle is phrased as a question (“Our Last, Best Hope for a Future on Earth?”) the answer is clear: If we want to keep going, he argues, there needs to be fewer of us. Weisman spoke with Salon about our cross-cultural impulse to be fruitful and multiply, and his quest to find a more sustainable mantra for humanity. This interview has been lightly edited for length and clarity.
There’s a lot that’s written about population, but nearly all of it is really slanted. It’s by somebody who’s got a definite point of view and either the point of view is denial – either because the idea that we would have to place some kind of limit on human numbers would conflict with the way they make their money or possibly with their religious views, or simply a denial that really comes from deep within all of us.
We’re just creatures like any other organism on this planet, in that we’re all in it for our own survival and secondly for our genetic survival beyond us. And we do that by making copies of ourselves. And historically, biologically, we make more copies than are needed, knowing that some of them aren’t going to survive.
But in the past couple of centuries we’ve gotten very good at surviving, through a combination of medical advances that help us live longer and help most babies live rather than die. There’s also much more food, which keeps a lot more people alive so that they can beget a lot more people. And suddenly we just really exploded. That’s a problem, and its one that we never really had before, so we never really evolved to the point where we could think about it very well.
I tried to approach this thing as a journalist, not as one of those people who take a strong stand about the whole thing. Because I’m not really that interested in us going extinct, or hastening our extinction, I really look for signs of hope, and I think there are a lot of them in that book. You may have felt that the preponderance of the evidence was not encouraging, and I admit we’re in a very tough place. That’s my conclusion as a journalist, and it’s going to be a pretty wild century. But within that century we have the means to do something about it. And it doesn’t mean inventing incredible new energy systems that don’t muck up the atmosphere, or somehow changing human nature so we all suddenly consume less or distribute our food more equitably, stuff like that. This involves technology that we already have.
There is a side benefit that is even possibly a contribution to humanity, which is that the best contraceptive of all is educating and empowering women, and men. What better world would we have then?
So given that the implementation of all this stuff would be incredibly cheap, I came away from this thing a little bit more hopeful than I did going in.
So, we’re at the point where we’re treating a lot of illnesses, we’re able to feed more people. If we got rid of all population constraints, how many of us would there be?
It really depends on our reproduction rate. And right now the way that we are reproducing, if it stays steady, we are headed to about 11 billion by the end of this century. That could change in a couple of interesting ways. One thing that this book does show is that our current reproductive rates are based on supplies and delivery systems of contraceptives. A lot of those supply lines are much more fragile than I realized before I ever got into this book. Just increasing our fertility rate by a half a child per woman could push us to 16 billion, not 11.
Or, in the other direction, by reducing it by a half a child per woman, we could be back to 6 billion by the end of this century. In The World Without Us, theoretically, I asked a demographics institute what would happen — setting aside all social issues — if we all participated in the Chinese one-child policy. By the end of the century, we’d be back to 1.6 billion, which is the number of us at the beginning of the 20th century — before medical advances and food technology like artificial nitrogen [fertilizer] suddenly quadrupled us within one century, which has probably never happened to any organism before.
So it’s kind of up for grabs, but every population projection that has been made in the past has turned out to be conservative. This 11 billion figure that’s the most likely scenario at this point is a new update, by the UN’s population division.
And what’s the limit on how many people is the earth capable of supporting?
We don’t know for sure, but there are a lot of signs that we’ve already reached that, and that we have to start gradually cutting back. Nature doesn’t let any species exceed its carrying capacity. It always knocks them back. Locusts go through cornfields, and then they run out of corn, and then there’s a big die-off.
The human race right now has managed to push the limits. It used to be that our numbers were held in check, to a certain extent, by the amount of plant life on this planet. And that amount was determined by nitrogen fixing, the natural way. A few plants, such as legumes, have bacteria around their roots that allow them to capture nitrogen from the air and fertilize themselves. When we invented artificial nitrogen, suddenly we hugely increased the amount of plant life. That created more food, and we could keep growing our population. Put another way, if we hadn’t invented artificial nitrogen – fertilizer — at least40 percent of us wouldn’t be here. Possibly more.
So, if we could keep producing artificial nitrogen forever, maybe we could continue at this population, 7 billion. But we’ve been noticing for quite a while that artificial nitrogen comes with a heavy cost. For one, it’s derived from fossil fuels, whose mining is problematic. Two, you have to apply energy from fossil fuels to create the artificial nitrogen. That’s a double whammy with fossil fuels, which contributes to greenhouse gases, which now is not just increasing temperatures all over the planet, but is also re-jiggering the chemistry of the oceans, from which we spring, which govern biological processes on this planet to the extent that we don’t even know for sure yet.
So a whole lot of things may be changing because of all the carbon dioxide the ocean is absorbing, and as a result, acidifying. Then there’s the fact that the excess of artificial nitrogen itself creates a very serious greenhouse gas: nitrous oxide. And there’s the mess that it makes as it runs down our rivers. After the Aswan Dam was built in Egypt, all that silt that used to flood the Nile, and the fields alongside it, which used to revitalize the soil of Egypt, suddenly that wasn’t happening anymore. So they started using artificial nitrogen there, and I think within five years, fish catches in the Mediterranean were down by 50 percent.
In the long term it’s just not sustainable.
It doesn’t sound like it’s sustainable. There’s one other little feedback loop in there, that all this global warming increases the temperature so with every one degree centigrade — and this has been published widely, including in the Proceedings of the National Academy of Sciences — crop harvest dropped 10 percent. And that doesn’t mean that this is going to happen linearly. When we get to a two degree warming, which is where we’re headed now — in fact we’re headed beyond there — crops may drop off even more precipitously.
Given that one of those crops is rice, and an enormous amount of rice grows in coastal areas, imagine the cost of putting up dykes to protect entire coastlines of agriculture. Even if they don’t get swamped by a rising sea, salt water incursion happens before entire parts of coastlines start to disappear. So that’s going to affect an awful lot of our food production.
Did you happen to see the recent New York Times op-ed about how overpopulation is not the problem? It seemed to counter your entire thesis.
Wasn’t that hilarious? He [Erle Ellis] started out by saying there is no environmental reason for people to go hungry now or in the future. And I’m thinking, “Aw, that must be so comforting to the planet’s billion-plus people who are already hungry.”
It’s a techno-fix. Human ingenuity is always going to be able to produce new solutions, and human population itself is a mother of invention. It breeds more ingenuity and it stimulates us to solve problems. Of course, the problems are being caused by more people.
He quotes in there an economist who – I mean that’s really old news, comes right out of the same school as Julian Simon, who I talk about it my book. He was a University of Maryland professor, and he wrote basically that human ingenuity was the best resource, and we could just go on endlessly. At one point, he made this bet with Paul Ehrlich and John Holdren — who I mentioned in the book a lot and is now President Obama’s science adviser. The bet was that the size of these metal commodities would not increase in cost due to scarcity over the coming decade. It turns out that Ehrlich and Holdren lost that bet, because the recession hit in the 1980s. And ever since, all of these economists point to this thing as proof that Ehrlich was wrong.
The part that they leave out is that in any other decade, even The Economist has written that Ehrlich would have won the bet. It was an anomalous decade. And Ehrlich and Holdren then bet Simon the same thing: pick five environmental indicators that you think in ten years won’t become scarcer, or that won’t be in some more critical or destabilizing position than they are now.
He wouldn’t take that bet, right?
He refused the bet.
But my favorite thing is that in Simon’s last book, which he wrote the year before he died in 1994, he made this statement that we now have the technology to feed, clothe, and buy energy for an ever-growing population for the next 7 billion years. So Paul and Ehrlich did the math on that, and found that that’s probably unlikely — because at the current world population growth rate then, within 6 thousand years the mass of the human population would equal the mass of the universe.
You know, people say that even though the earth doesn’t grow, we can keep growing limitlessly. Economists love this because economics is based on constant growth. And they’ve actually deluded themselves into believing that we can keep growing limitlessly, even though we’re in a limited space, using limited resources. So, yes we can come up with techno-fixes that will stretch things for a while, but ultimately things that stretch break and these techno-fixes end up causing unanticipated problems.
Like the Green Revolution…
Of course. And that’s the other thing. The Green Revolution is constantly cited by these people as further prove that Ehrlich and Holdren were wrong, because the famines they predicted didn’t happen. But as I hope you found in my book, when I visit the Green Revolution centers in Mexico and then Philippines — the Philippines for rice, Mexico for corn and wheat — I didn’t find any scientists who believe that. In fact they all trotted out the Noble Peace Prize acceptance speech by the Green Revolution founder Norman Borlaug, who stated that there is no way that we can do anything other than buy some time with increased food production technologies unless we come together with the fight for population control. Otherwise it’s just going to swamp us.
Borlaug was on the board of all these different population groups all of this life. It was his chief concern. I think now we’ve kind of reached the point where there are so many environmental indicators to suggest that we are bursting at our seams, and that we have kind of become too much of a good thing.
No one asked us to be born. And I feel that’s a hard thing to come up against when we talk about how there are just too many of use here. Since we are here now, how do we not be part of the problem?
Well I think, if you will forgive me, your question implies the same kind of wishful thinking that I and everyone else indulge in at times. We can’t be not part of the problem. As I state in Countdown, in the 20th century we’ve kind of redefined the concept of original sin. Every one of us just by existing, with our first exhalation, we are contributing to the problem: that every single human being stresses out the environment beyond the carrying capacity of the planet.
From where we do we throw away all of the diapers to just simply what our carbon legacy is going to be. There is a study from Oregon State that I cite in there that each child that a mother bears is going to keep multiplying her carbon output, because they’re going to have more children, and each one of them is going to be depending on energy, depending on food, depending on materials for shelter — all of those things which are energy intensive. As much as I am an advocate of renewable energy, we haven’t come up with any technology that can yet fuel all of our industries and our vehicles and heat our homes at the numbers of us that are demanding this fuel right now.
What we can do, though — very, very effectively — is do what Joseph did in the bible. He was born at a time when “be fruitful and multiply and fill the earth” was an active command that people believed in. Which of course is the beginning of every single religion and every single nation: you want to become more numerous so that you can control your territory, lest someone else more numerous and powerful than you pushes you away. You read Genesis and there are chapters that are just all about population growth and reproduction. You know, all these “begats.” Guys are begetting more sons who are begetting even more. And then you get to Joseph, who may have been our first ecologist, who realized that Egypt was entering a dry cycle. He held himself to one wife and just two children and he warned the Pharaoh of Egypt that to survive you have to conserve, and you need to refrain from embracing so much. And as a result they got through the famine.
I think that we are in those kinds of urgent times again. We have expanded in such a way that we are endangering ourselves. These horrible floods that are going on in Colorado right now can be directly traced to what we have done. We’ve exacerbated droughts, we’re having more forest fires than ever as a result, and now the land can’t retain the water because the trees are gone. So Colorado is washing away, even as you and I speak here.
By holding ourselves to two or fewer children we will enormously cut down on humanity’s environmental impact over the coming century. And the reason why I went to so many countries for this book was to kind of take the emotional and cultural temperature of great swaths of our belief systems and our nationalities and our religions, to see: is there anything, either in their histories or liturgies or current situations that might convince them that would be in their best interest. Though a lot of it was very difficult, such as the extremists in Israel — that sandbox that has so little water and where extremes on either side are trying to out-populate each other — I still found everywhere I went some really eloquent cultural expressions or historical events that are part of the culture that indicate that we don’t have to change people’s beliefs or tell them that they’re wrong. That there is something within their beliefs that would accommodate all of this. It’s in Islam, it’s in Judaism — there’s this ecological Talmudist in the beginning of my book that talks about – it’s in Christianity.
It may not be in the Catholic church. I don’t know if you read that chapter, but the Catholic Church has painted itself into a corner form which it cannot emerge, because its only power, ever since it lost all its land in the 19th century, is derived from a concept of papal infallibility. But unfortunately that means that if the pope is infallible, then every pope was infallible, and then the same pope that start saying that the birth control is bad couldn’t have been wrong. So now birth control is bad.
But surrounding that little tiny enclave in the Vatican, there’s this huge Catholic country called Italy whose fertility rate is well below replacement and the way it got there is that it provided education and opportunity to its woman. So your classic Italian woman now is not that mama with her apron and seven kids tugging on it. She’s got a college degree — more per capita of Italian women have PhDs, I think, than almost anybody, and she’s got something important to contribute to society, and something interesting to do with her life. So she restricts herself to two children or fewer so she can do those kinds of things. That’s a very good prescription for the world.
The question of the book is about finding our “last best hope for a future on Earth,” and it sounds like, with that one institution as exception, you have found that.
Well I think there is an exception within that institution because most Catholics use birth control. They’re certainly willing to if it’s made available to them.
As a journalist, I don’t want to come out and make a statement: “this is our last best hope.” I want to raise the question, present the facts and let readers decide for themselves. Just as my research presented the facts to me. I really went out trying to figure out: Is this something that is as big a problem as I suspected it might be, and if so is there something that we could really do about it? I’ve presented my findings in the book and I really think they speak for themselves.
I do think that there really is a hope in this. I know it might seem like a long shot to a whole lot of people, like how can we convince everybody to have fewer kids? But I don’t think that’s anywhere near as long a shot as coming up utterly clean energy — which still wouldn’t solve a lot of our problems, such as solving consumption. If we had utterly clean energy, we’d be producing more stuff, and we’d be consuming even more. And we’d be creating even more traffic, and we’d be sprawling even further across the land. And that urban sprawl is not only unsightly, but cities were positioned where they were initially for a reason. They were near good soil, and some of our best soils are now under pavement.
In any event, by the end of my research it just seemed academic to me. Of course there’s too many of us. But it’s almost like, how can we even be arguing that? But I actually grew to understand that, in the second to last chapter of the book, you know were I compare it to wildlife management –which is somewhat of an oxymoron but we do have to do it because we recognize it that in our national parks, if predator or prey get out of balance with one another, the system collapses – it’s easy to see that when you are looking at deer and wolves. When you’re looking at your own species, it’s very hard to be objective. Just like it’s hard for you and me to be objective about ourselves. We are deeply, personally involved and it’s hard to step away. To the best of my ability that’s what I did for this book.