conflicts, like the ones ongoing today in the Middle East and Africa, is evaluated. Major laws and treaties, once made, are assumed to stay in place.
A decades-long global depression, an unstoppable killer disease pandemic, a meteorite impact, or other low-probability, high-impact event is not imagined here. However, this rule is relaxed in Chapter 9 to explore six plausible, if unlikely, outcomes, like an abrupt climate change or the collapse of global trade—both of which have happened before and could happen again.
4. The Models Are Good Enough.
Some of the conclusions reached in this book stem from experiments using computer models of complex phenomena, like climate and economies. Models are tools, not oracles. All have their flaws and limitations.10
But for the broad-scale purposes of this book, they are excellent. I will focus on the robust, uncontroversial messages of these models rather than push the limits of their capabilities. As before, this rule is relaxed in Chapter 9 to explore some plausible outcomes lying outside our current modeling capacity.
The purpose of these rules is to introduce conservatism to the thought experiment. By favoring likely, forseeable trajectories over unlikely, exciting ones, we avoid sacrificing a more probable outcome to a good story. By pursuing multiple lines of argument rather than one grand idea, we avoid the so-called “foxes and hedgehogs” trap, by lessening the likelihood that an important actor will be overlooked.11 By concentrating on the most robust simulations of computer models, we steer the conversation toward the science that is best understood, rather than poorly understood.
Why even try to project forty years into the future anyway? To imagine the world in 2050, we must closely study what is happening today, and why. By forcing our minds to take the long view, we can identify factors that might seem beneficial in the near term, but lead to undesired consequences in the long term, and vice versa. After all, doing good things (or at least, less bad things) for the long term is a worthy goal. I certainly don’t believe the future is predetermined: Much of what does or does not happen forty years from now rests on actions or inactions taken between now and then.
Some of the changes I will present will be perceived as good or bad, depending on the reader’s own perspective. To be sure, some of them, like species extinctions, no one wishes to see. But others, like military spending and energy development, evoke valid, strongly opposed reactions. My goal is not to argue one side or another, but to pull together trends and evidence into a bigger picture as well and objectively as I can. The reader can take it from there.
But before we can intelligently discuss the future, we must first understand the past. In roughly historical order of their rise in significance, here are four global forces that have been busily shaping our 2050 world for tens to hundreds of years.
FOUR GLOBAL FORCES
The first global force is demography, which essentially means the ups, downs, and movements of different population groups within the human race. Demographic measures include things like birth rates, income, age structure, ethnicity, and migration flows. We shall examine all of these in due course but for now, let us start with the most basic yet profound measure of all: the total number of people living on Earth.
Before the invention of agriculture some twelve thousand years ago, there were perhaps one million persons in the world.12 That is roughly the present-day population of San Jose, California. People foraged and hunted the land, living in small mobile clans. It took
Our second billion arrived in 1930, a mere 130 years later. The global Great Depression was under way. Adolf Hitler led his Nazi Party to stunning victory in Germany’s Reichstag elections. My Italian immigrant grandfather, then living in Philadelphia, was thirty-three years old.
Our third billion came just thirty years later in 1960. John Kennedy beat Richard Nixon in the U.S. presidential race, the first satellites were orbiting the Earth, and I was a scant seven years from being born.
Our fourth billion took just fifteen more years. It was 1975 and I was eight. The U.S. president Gerald Ford escaped two assassination attempts (one by Charles Manson’s murderous henchwoman Lynette “Squeaky” Fromme), the Khmer Rouge had taken over Cambodia, and the movie
Our fifth billion came in 1987, now just twelve years after the fourth. The Dow Jones Industrial Average closed above 2,000 for the first time in history and the Irish rock band U2 released their fifth album,
Our sixth billion arrived in 1999. This is now very recent history. The United Nations declared 1999 the International Year of Older Persons. The Dow Jones climbed above 11,000 for the first time in history. Internet hookups ballooned and millions of songs, to the dismay of U2 and the rest of the music industry, were swapped for free on Napster. Hugo Chavez became president of Venezuela, and a huge chunk of northern Canada quietly assumed self-rule as the new territory of Nunavut. By then, I was a young professor at UCLA, working toward tenure and starting to notice things. The world vacillated between nervous fretting about Y2K and excitement over the dawn of a new millennium.
11,800 years . . . 130 years . . . 30 years . . . 15 years . . . 12 years. . . . The length of time we need to add another billion has petered down to nearly nothing. One billion is more than triple the 2010 population of the United States, the third most populous country on Earth. Imagine a world in which we added one-plus USA, or two Pakistans, or three Mexicos,
This extraordinary acceleration, foreseen over two centuries ago by Thomas Malthus,13 burst into popular culture again in 1968 when Paul Ehrlich, then a young biology professor at Stanford, jolted the world with
Arguments against Ehrlich’s ecological approach to human beings charged that it underestimated the limits of our technology and ingenuity. So far, these arguments appear to have been correct. Our numbers have surged on and Ehrlich’s scariest predictions have, as yet, failed to materialize. But even so, generations from now, our descendants will marvel at the twentieth century, a time when our numbers shot from 1.6 to 6.1 billion in a mere blink of time.
What triggered this enormous twentieth-century population spurt? Why did it not happen before, and is it likely to continue into the future?
Fast population growth behaves a lot like a personal savings account. Just as its account balance depends on the spread between the rates of deposit versus spending, the balance of people on Earth depends on the rates at which new people are created (the fertility rate) versus how fast existing people disappear (the death rate).15 When the two rates are equal, population holds steady. When they diverge or converge, population rises or falls accordingly. It doesn’t really matter whether birth rates rise or death rates fall; what matters is the spread and whether rate adjustments are staggered in time or happen simultaneously. Most importantly, once a run-up (or decline) has happened, we are stuck with the new population level, even if the gap between fertility and death rates is then closed and population stability is returned.
From our earliest beginnings until the late nineteenth century, our fertility and death rates, on average, were both high. Mothers had more babies than today, but few of them survived to old age. In the preindustrial era, famine, warfare, and poor health kept death rates high, largely offsetting high fertility. The global population of humans trickled higher, but only very slowly.
However, by the late nineteenth century, industrialization had changed everything in Western Europe, North America, and Japan. Mechanized food production and distribution reduced famine deaths. Local warfare disappeared
