Charles C. Mann: How Will We Survive When the Population Hits 10 Billion? (Transcript)

Charles C. Mann is an American journalist and author, specializing in scientific topics. His book 1491: New Revelations of the Americas Before Columbus won the National Academies Communication Award for best book of the year.

Here is the full text of Charles’ TED Talk titled “How Will We Survive When the Population Hits 10 Billion?”

Charles C. Mann – TED Talk TRNSCRIPT

How are we doing? No, no, no, by that, I meant, how are we, homo sapiens “we” doing as a species?

Now the typical way to answer that question is this. You choose some measure of human physical well-being: average longevity, average calories per day, average income, overall population, that sort of thing, and draw a graph of its value over time.

In almost every case, you get the same result. The line skitters along at a low level for millennia, then rockets up exponentially in the 19th and 20th century.

Or choose a measure of consumption: consumption of energy, consumption of fresh water, consumption of the world’s photosynthesis, and draw a graph of its value over time. In the same way, the line skitters along at a low level for millennia, then rockets up exponentially in the 19th and 20th century.

OUTBREAK

Biologists have a word for this: outbreak. An outbreak is when a population or species exceeds the bounds of natural selection. Natural selection ordinarily keeps populations and species within roughly defined limits.

Pests, parasites, lack of resources prevent them from expanding too much. But every now and then, a species escapes its bounds. Crown-of-thorns starfish in the Indian Ocean, zebra mussels in the Great Lakes, spruce budworm here in Canada. Populations explode, a hundredfold, a thousandfold, a millionfold.

So here’s a fundamental lesson from biology: outbreaks in nature don’t end well.

Put a couple of protozoa into a petri dish full of nutrient goo. In their natural habitat, soil or water, their environment constrains them. In the petri dish, they have an ocean of breakfast and no natural enemies. They eat and reproduce, eat and reproduce, until bang, they hit the edge of the petri dish, at which point they either drown in their own waste, starve from lack of resources, or both.

The outbreak ends, always, badly.

Now, from the viewpoint of biology, you and I are not fundamentally different than the protozoa in the petri dish. We’re not special. All the things that we, in our vanity, think make us different — art, science, technology, and so forth, they don’t matter. We’re an outbreak species, we’re going to hit the edge of the petri dish, simple as that.

Well, the obvious question: Is this actually true?

Are we in fact doomed to hit the edge of the petri dish?

I’d like to set aside this question for a moment and ask you guys another one.

If we are going to escape biology, how are we going to do it? In the year 2050, there will be almost 10 billion people in the world, and all of those people will want the things that you and I want: nice cars, nice clothes, nice homes, the odd chunk of Toblerone.

I mean, think of it: Toblerone for 10 billion people. How are we going to do this? How are we going to feed everybody, get water to everybody, provide power to everybody, avoid the worst impacts of climate change?

I’m a science journalist, and I’ve been asking these questions to researchers for years, and in my experience, their answers fall into two broad categories, which I call “wizards” and “prophets.”