Seven Billion: Ever-Expanding Humanity?

by Bill Chameides | October 31st, 2011
posted by Erica Rowell (Editor)

Permalink | 1 comment

The world’s human population officially reaches seven billion today. But in my opinion, when it comes to the challenge of sustainability, the number of people on the planet is not the whole story. (NASA)

A milestone or a millstone?

You’ve probably heard. Today’s the day — the United Nation’s designation for when the human population hits seven billion. (Read more on the U.N. estimate here and more on Danica May Camacho, the Philippines-born baby girl who’s been designated number “seven billion,” here.) Quite a testament to our DNA’s ability to be fruitful and multiply; that’s the milestone part. But there’s also the millstone around our necks: Are our population and its upward trajectory sustainable?

In my opinion the number of people is only a part of the sustainable equation, but more about that later.

Not All That Much When You Think About It

Before we get all worked into a lather about our numbers, a little perspective might help. Sure seven billion is sizable, but consider these numbers:

As far as the microbes are concerned, we’re just tasty morsels to feed on or comfy little homes to squat in. I suspect they’d say, if asked about our milestone, “Cool, bring ‘em on.” Of course, they’re not the smartest things out there — certainly not nearly as smart as we are — and so perhaps they’d be underestimating the destructive capacity of our, by comparison, paltry numbers.

My own opinion is that they’ll be among the ones, in the billions, doing their thing on our rock long after we’re dead and gone. And while we’re speaking of billions, let’s tip our hats to Carl Sagan and keep in mind that there are almost certainly all kinds of folks hanging out on all those habitable planets orbiting around some of the seven thousand billion-billion (and counting) stars out there. So let’s not get too carried away with our role in the big scheme of things.

Seven Billion Is Actually a Pretty Common Amount These Days

Here’s another way to look at it. Consider these other “seven billion” statistics:

  • The number of hot dogs Americans eat each summer (Source:
  • The annual tobacco-related health-care costs (in $US) in Germany (U.S. costs are $81 billion) (Source: World Health Organization)
  • The amount of money (in $US), roughly, a single trader named Jerome Kerviel fleeced out of the French bank Société Générale (Source: Agence France-Presse)
  • The estimated worth of Facebook’s Mark Zuckerberg in September 2010 (Source: Forbes)
  • The amount of money (in British pounds) Goldman Sachs budgeted to salaries and year-end bonuses in 2008 (Source: The Daily Mail)

But, just to remain fair and balanced, here’s one amount that pales in comparison to our seven billion strong: the amount of money paid to the world’s 500 top chief executives — in 2010 only $4.5 billion.

Some Other Statistics to Think About

Human population is certainly a key factor in assessing our place and our future on planet Earth. But there is another important aspect of this assessment we sometimes lose sight of when we focus on population alone: resources — specifically, their use and allocation.

The rapid rise in human population has been strongly correlated with our use of resources and our expenditures of energy. We’re all familiar with graphics that show the close correlation between human population and energy usage worldwide. But it’s important to bear in mind that the rise in energy use is not just about more people but about more people using lots and lots more energy.

Below is an adaption of one of my favorite illustrations from a 1971 issue of Scientific American.

(After E. Cook, “The Flow of Energy in an Industrial Society,” Scientific American, 1971, p. 135.)

Within the graphic’s main story lies another story. Some of us live in the “Technological Era,” others not so much. In fact, the poorest among us are getting by, at least in terms of their energy use, more like the “Advanced Agriculture” folks. According to a 2004 World Energy Assessment [pdf], the average North American uses more than 10 times the energy a sub-Saharan African uses, the average European about six times more. An average person from one of the world’s economically developed nations uses almost three times more energy than the average person in the world.

If one were to argue that humanity is approaching the planet’s carrying capacity with its new milestone of seven billion, that would imply that the planet would be severely strained by a population of somewhat more than two billion if they were living like us.

So, is the problem over-population? Or is it meeting the aspirations of our fellow human beings without ruining the planet in the process? I guess I’d have to say both.

filed under: agriculture, energy, faculty, sustainability
and: , , , , , , , , , , , , , , , , , , , ,

1 Comment

All comments are moderated and limited to 275 words. Your e-mail address is never displayed. Read our Comment Guidelines for more details.

  1. Hank Roberts
    Nov 7, 2011 Old problem, another collapsing fishery — hugely important, going fast

©2015 Nicholas School of the Environment at Duke University | Box 90328 | Durham, NC 27708
how to contact us > | login to the site > | site disclaimers >

footer nav stuff