I just read the latest “contrarian” anti-environmentalist opinion piece on the New York Times Op-Ed page, and I feel that my head is about to explode.
Here is Erle C. Ellis, professor of geography and environmental systems at the University of Maryland–Baltimore County, deniersplaining how the world works to all those fretful, lily-livered scientists out there:
MANY scientists believe that by transforming the earth’s natural landscapes, we are undermining the very life support systems that sustain us. (...) Disaster looms as humans exceed the earth’s natural carrying capacity. Clearly, this could not be sustainable.
This is nonsense. (...) These claims demonstrate a profound misunderstanding of the ecology of human systems. The conditions that sustain humanity are not natural and never have been. (...)
The world population is now estimated at 7.2 billion. But with current industrial technologies, the Food and Agriculture Organization of the United Nations has estimated that the more than nine billion people expected by 2050 as the population nears its peak could be supported as long as necessary investments in infrastructure and conducive trade, anti-poverty and food security policies are in place. Who knows what will be possible with the technologies of the future? The important message from these rough numbers should be clear. There really is no such thing as a human carrying capacity. We are nothing at all like bacteria in a petri dish.
Why is it that highly trained natural scientists don’t understand this?
Well, if I had to guess, I’d say that real scientists “don’t understand this” because they are able to add and subtract.
Without getting into any of the other obfuscation and wishful thinking that one would need in order to follow Dr. Ellis’s line of reasoning, let’s just look at the raw numbers and let them speak for themselves.
Start with today’s human population of 7.2 billion and the estimated 9 billion population in 2050 that Dr. Ellis is so looking forward to. These two numbers imply a growth rate of just a smidge over 0.6 percent a year.
Sounds totally sustainable, right? I mean, if ancient humans invented agriculture and with it were able to grow at a reasonable clip for hundreds of years, then invented irrigation and all sorts of other new technologies to keep up the pace for whole millennia, then as Dr. Ellis says: “Who knows what will be possible with the technologies of the future?” Indeed!
So, let’s image what the future will be if humanity keeps on the 0.6 percent a year growth path indefinitely.
Hmm. At that rate, in about 1,264 years our population will have grown to about 14 trillion people, which means that the combined mass of humanity will outweigh the entire biomass of the earth. At that point, we’ll have to start getting our carbon from other planets, I suppose.
Then, as space technology allows us to keep up the same unstoppable 0.6 percent a year growth, we run into another little roadblock about 3100 years from now, when we outweigh all the fresh water on earth. No problem! No doubt we’ll have instant, free desalinization by then. Still, just 560 years later we outgrow all the water in all the oceans on earth.
But I’m forgetting: by then, our spaceships will have colonized the entire solar system. Ah, of course. Still, we run into a little trouble around 7,200 years from now when we outweigh the Sun and all the planets. Okay, on to the stars! (Presumably by then we’ll have warp drives and replicators.)
Oops—just 4,500 years later (around the year 13744 AD), we outweigh the entire galaxy. I really hope we have superwarp drives by then, because we’ll need ’em.
Yet only 1240 more years pass by before we outweigh our entire local supercluster of galaxies.
And after another 2900 years, around the year 17862, we outweigh the entire observable universe. Do you think we’ll run into a “human carrying capacity” problem by then?
My point is: indefinite exponential growth at any growth rate, no matter how small, isn’t just unsustainable. It is literally impossible. Even with new supertechnologies that violate every known law of physics, it just cannot be done.
So, at some point human population growth comes to an end. The question is: when?
And another good question is: why can’t we ask that question? Why shouldn’t we ponder the answer and come up with the best way forward?
Plunging forward blindly into the future, when we have so many means unavailable to our ancestors of measuring our present condition and modeling future conditions, is not the answer. Yes, technology has made it possible for us to sustain a higher population than Malthus ever dreamed of. But that technology includes our systems for monitoring where we are, where we’re going, and planning for the future. Don’t tell us to close our eyes, shut up, and just keep going. That’s the way of bacteria in the petri dish. We can do better, we must, and we should.