Feb 1, 2014
Today there are more than seven billion people on the planet, a number the demographers say we reached October 31, 2011. The general consensus among population experts seems to be that the Earth can support between nine and 10 billion resident humans, and we’ll reach that point somewhere between the years 2050 and 2100.
A couple mornings ago, apropos of a general winter malaise intensified, no doubt, by the long polar vortex that’s defined our January, David and I were mulling over these numbers. Thinking unhappy thoughts about water shortages already experienced around the globe. Wondering aloud about centuries of misbegotten land use decisions. Speculating about a climate shifting, for whatever reasons, in ways we, none of us, fully comprehends. If two or three billion more of us are going to live here (perhaps during my lifetime—hey, I’ll only be 83 in 2050!), it seems pretty obvious that how we create and utilize energy, water and food is going to have to change.
But what do we know, right? We’re just two geeks addicted to NPR’s “Science Friday” and “Living on Earth.” And while riffing on various population tipping point scenarios does have its morbid charms, pondering the miracle of the Large Hadron Collider or the migration of the Red Knot (an extremely cool shorebird), is really more our style.
Then David posed a question I’d honestly never considered: How many humans have died? Although essentially the same, this question is just a little bit different than asking how many humans have lived, because it places the focus on each absence. Each life completed, however long or short, peaceful or painful. Ended, full stop, as each of our seven billion lives will end, one day, one way or another. Rather than the image of a planet teeming with life, generation upon generation—50,000 years of Homo sapiens—my mind saw a bone-yard, ashes blowing like dry dirt in an Iowa dust storm. It took me aback. Quite an image for a Wednesday morning.
But the question remained: How many?
If you’re like me, you’ve retained a vague childhood notion that the vast majority of people who have ever been born are alive right now. Admittedly, this doesn’t seem to make a lot of sense when you stop and think about it. Fact is, I’d never stopped to think about it before. I couldn’t hazard a guess as to how many humans had died on planet Earth.
So, we looked it up. And while such a question can’t elicit a purely scientific answer, since there is no hard and fast demographic data for 99 percent of human existence, the consensus among anthropological demographers appears to be that about 100 billion (with a “b”) humans have died on this planet. That’s subtracting our current population of seven billion from the 106-108 billion range of estimates for the number of people who have ever lived.
The bone-yard just got a whole lot bigger. I envisioned a wall of ashes moving toward me not unlike the tsunami of sand in Lawrence of Arabia. I sat down.
“Wow! Kinda puts Jay-Z and Beyonce in perspective,” I quipped, trying to distract myself from the ash-storm.
But it didn’t. It doesn’t. Not really. Because I don’t know about you, but I don’t naturally think in terms of 100 billion anything. And in order for 100 billion to be a number that can render perspective, one must, at a minimum, be able to think in terms of it. I’m pretty sure I remember hearing that Beyonce’s record sales had recently topped 100 million. A mere third of the population of the United States. Pfft! What help is that?
As I turned to cracking eggs for breakfast, I thought: I’m gonna need a bigger framework. But what? The universe itself is thought to be between 12 and 14 billion years old. The earth a mere babe at 4.5 billion. My favorite Silurian age fossils, brachiopods abundant on the ridgetop here at Brightside, are only 420-460 million years old. What existed 100 billion years ago? Nothing. No time. No space. I swiftly told myself not to get started thinking about that or we’d never eat.
It wasn’t until the following bitterly cold, bitingly crisp night, as I stood in the driveway, calling for our dog, Buddy, that I looked out and up and thought: Stars in the Milky Way? There are thought to be 100-400 billion stars in the Milky Way Galaxy. If you are one of the relatively few of the seven billion people alive on Earth who can see the Milky Way, within which Earth is but one of perhaps 100 billion planets, then you know well the gauzy strip of layered pin-pricks so evocative of its name. Under the best of circumstances—a moonless, haze-free night, unobstructed by man-made lights—we see at most 10,000 stars with our naked eyes. It turns out that the dazzling multitude before us is but a fraction of a fraction of a fraction of a pin-hole view of the neighborhood.
Still, my glimpse of the Milky Way helped form a framework for the inconceivably enormous number I struggled to draw a bead on: 100 billion. I stood in the frigid air, looked up at the stars, multiplied them, again and again and again. I remembered that this planet and all life on it is made from stars. From stardust we are made, and to planetary dust returned—temporarily. It’s this planet’s distant fate to be subsumed by our closest star, the Sun. And so, one day, the circle will be completed.
Why did this thought relieve me? Perhaps for the cosmic is-ness of it. The stark fact of the circle of life on the scale of planetary time. From stars we came and to the stars we will return, along with more than 100 billion of our fellows. We’ve simply no choice in the matter.
Our human remains jumbled in pits, mummified in tombs, embalmed in caskets, preserved in formaldehyde, studied in schools, cremated and saved, scattered to the wind, blown across desert and prairie, eaten by animals, disappeared but not lost to the planet, which houses each of us somewhere in crevasse or niche. And by this simple fact, makes us one. One body. One Earth. At some point, the attempt to tease it all apart is as corny as it is futile.
Who would attempt to tease apart the leaves that form the loam of the forest floor? Who would want, once the leaves have become part of the soil from which they grew, to distinguish the white oak from the red oak, the birch from the beech, the black walnut from the black locust? It’s all loam to the seeds that sprout within it. What a silly thought. Why bother?
I awoke in the middle of the night thinking of leaves.
It turns out that a mature oak tree grows, on average, 200 thousand leaves a year. Two hundred thousand is the population of Richmond, VA, Spokane, WA, or Montgomery, AL. Two hundred thousand is a number one can get a grip on.
Now imagine a forest of 500 thousand trees. That’s somewhere close to 800 acres. Which is somewhere close to 1.25 square miles. And all the leaves that reach the ground, one way or another, in such a forest represent all the human beings who have ever died on Earth. I can picture it. Can you?
Leaves that let go and fall gently. Leaves that first sicken and die. Leaves wrenched and lashed by wind. Leaves plucked by birds. Leaves stripped by machines. Leaves eaten and digested by animals. Leaves that dry and crumble, their bodies disappearing as their stems remain attached to the limbs that gave them life.
Just one year in the life of 100 billion leaves.