This past week the world passed a statistical milestone. As far as I can tell, it went unnoticed. When I mentioned the number to someone in The Naturalist's Notebook, she thought I had mistakenly added three zeroes to the end. I hadn't.
The population of the Earth has now grown by 50 million people since January 1 of this year.
That gain (births minus deaths, as calculated by population-projection experts) represents as many people as currently live in New York, Los Angeles, Chicago, Houston, Phoenix, Philadelphia, San Antonio, San Diego, Dallas, San Jose and the next 47 largest U.S. cities combined. Between the time you woke up today and the time you wake up tomorrow, the world will have added enough people to fill a city the size of Tacoma, Washington.
Oops. While I ate lunch just now the world added another 10,000 people.
This is a touchy subject. Everyone loves kids, and few outside the Chinese government believe in limiting how many children a woman may bear. To advocate growth-slowing measures—family planning, birth control, increased education of women in poor countries, revised tax policies that wouldn't encourage having large broods—is to incur the wrath of powerful political, cultural and religious forces. When was the last time you heard an elected official even mention population growth?
But that growth fuels every environmental problem, from pollution to habitat loss to overfishing of the oceans, and contributes to political instability and global poverty (half the people now alive get by on $2.50 a day or less). Imagine how different the world might be if the population hadn't increased from 3 billion in 1959 to 4 billion in 1975 to 5 billion in 1987 to 6 billion in 1999 to 6.86 billion today. According to projections, we'll hit 7 billion in 2012, 8 billion in 2028 and 9 billion in 2044. That's like adding another China almost every decade.
If those numbers are too big to absorb, let's go back to the 50 million increase so far in 2010. Imagine the panic that would ensue if the world added 50 million grizzly bears in eight months. Or 50 million tigers. Or 50 million gorillas. We're being overrun! It's not safe to go to the mall! Load your guns!
Oddly enough, we don't get so worked up over the impact of our own swelling ranks. We might be saddened to hear that the number of tigers has dropped by 98 percent over the last century and that three of the nine tiger sub-species have become extinct in the last 50 years, but we don't link that sort of subtraction to our own multiplication. Ninety percent of the world's large-fish population is gone? Gosh, I wonder what happened? Fifty thousand animal and plant species are vanishing each year, the highest extinction rate since the dinosaurs died off? Jeez, I sure wish those damned destructive beavers would join them!
Population growth is also reshaping world politics and business, of course. You can interpret the significance of this however you want, but according to U.N. figures, nine countries will be responsible for half the population increase between now and 2050: India, Pakistan, Nigeria, Congo, Bangladesh, Uganda, the U.S., Ethiopia and China. By 2050 India is projected to be the world's largest country (1.4 billion), followed by China (1.2 billion), the U.S. (439 million, up from its current 310 million), Pakistan (309 million), Indonesia (280 million), Nigeria (259 million) and Bangladesh (258 million, in a country that is going to lose a sizable portion of its land over the next several decades as sea levels rise).
U.N experts foresee the population leveling off at about 9.2 billion around the year 2050. Their expectation is that birth rates will decline with the spread of education and affluence. You can imagine the consequences of more and more of those 9.2 billion people living—and consuming—like those of us in the U.S.
All of which is to say, how come we never talk about any of this?