Bomb Squad

In 1968, Paul Ehrlich warned in The Population Bomb that exploding population would cause widespread famine and resource depletion within 20 years. Hasn’t happened—not yet. The Green Revolution staved off famine, and humans have proven resourceful, literally, in finding substitutes for scarce materials. Now, with world population exceeding 6.8 billion and heading beyond 9 billion by 2050, will Ehrlich’s predictions come true? Or was late economist Julian Simon correct in asserting that humans, even in ever-greater numbers, were the “ultimate resource” to innovate our way out of shortages? We interviewed three authorities on environment and population: Ehrlich, president of the Center for Conservation Biology and Bing professor of population studies at Stanford University; Bjørn Lomborg, author of The Skeptical Environmentalistand director of the Copenhagen Consensus Center; and Hans Rosling, professor of international health at Karolinska Institutet in Sweden and director of the Gapminder Foundation. Their edited remarks follow.

Paul Ehrlich

Global population has been unstable for several decades. We’re living on our capital, not on our interest. The deep, rich agricultural soils are disappearing at a much higher rate than they’re being formed. Fossil groundwater is being pumped out at much-higher-than-recharge rate. The loss of populations and species of other organisms, the working parts of our life-support systems, are disappearing. All the trends are going in the wrong direction.

Every study that’s been done shows that the state of wildlife and biodiversity is moving downhill rapidly virtually everywhere. Too many people think that the problem is loss of species. Well, before you lose species you lose their component populations, which is what deliver the ecosystem services. They are going at a horrendous rate. By the time people notice that a species is endangered, generally it is of little use to society in supplying any ecosystem services.

The biggest problems from my point of view from climate disruption are likely to be the change in precipitation patterns. On a planet that already has more than a billion people hungry out of 7 billion, the changing precipitation patterns and additional heating will make agriculture very, very difficult.

The whole problem of the U.S. being superconsumers and the rest of the world trying to emulate them is a really difficult problem. Depending on whose numbers you read and what assumptions you make, you’d need several more planets to support the number of people we have today at a U.S. lifestyle. My calculations, assuming no huge technological breakthroughs (of which there are no signs), indicate that we might be able support 2 billion people over the long term with a reasonable lifestyle.

Bjørn Lomborg

If everyone was at 2010 levels of efficiency, with the dramatically increasing economic welfare of China and India, that would put an unsustainable pressure on the world. But that’s not what we’re expecting. We’re expecting dramatic increases in efficiency in the use of virtually all resources.

The World Health Organization has estimated we can produce more food. Virtually all the increase in availability of food has not come from farming new land but from being able to get much more grain and produce from every hectare farmed.

Growing population is going to create more pressure on bio diversity and wildlife because most of the increase is going to happen in Third World countries, where very often you see unsustainable growth. If we want to focus on the solution, it has to be about making sure that people get rich faster. Rich people mostly live in cities where they have less of a footprint than in agricultural areas. Agriculture will increase in places where we already have production, in places that are not biodiversity hot spots.

Most of the energy resources we’re using are products just as much of innovation as they are [of] physical resources. We have dramatically increased the availability of gas through cracking. And clearly we have enough coal for many hundred years. We’re not going to run out anytime soon. Technology in the long run will overtake those concerns simply because we will find smarter and better technologies.

Barring being a very authoritarian state like China, telling people you can only have one child, there is very little you can do about population except to make sure you have good environment, you have better informed and richer citizens and better education of women.

Hans Rosling

Already 6.7 billion create an unsustainable strain on the environment. But there’s always been unsustainability. Why do people live in Sweden? Because the ecological use of Germany had become unsustainable 8,000 years ago. The hunting was gone. History is an endless list of unsustainable states.

A young student asked: Should we in the West let the poor in the developing world achieve the same material standard? As if it were a choice! There’s no choice about these 9 billion, and they will work hard for a decent standard for their children. It’s a fact. The promise is if child mortality is brought down in the whole world, family planning will be applied by all and world population will level off after 2050. But only if the poorest 1 to 2 billion fellow humans move into modernization.

Death is no longer able to control population (if you exclude nuke-mediated genocides), but two-child families can. The most forceful factors to achieve two-child families is good child survival, access to family planning, socioeconomic progress, and human rights for men and women to decide on family size. Urbanization is also good. All those things together yields two-child families.

I get scared by statements that we will be too many people. I hear lebensraum[German for “living space”]. I hear the Nazis talking in the 1930s. We cannot kill people to save the environment. After all, human rights are more important than the environment, I say, and the environment can be cared for if the rich countries get serious about it! And it’s not impossible! Professor Christian Azar coined the termpossibilist. I’m neither optimist nor pessimist, I am a possibilist. Don’t get too emotional: We can have a good world for 9 billion people if we get serious about making the right investments and regulations.

GREG BREINING writes about science, travel and nature for The New York Times,Audubon and other publications. Among his recent books is Super Volcano: The Ticking Time Bomb Beneath Yellowstone National Park. His latest, Paddle North: Canoeing the Boundary Waters–Quetico Wilderness, will be published this fall.