THE SOCIOLOGIST

The wall of his office hosts more screens than a stock market trading floor. Monitors with economic charts and trend lines update a few times each second.

I lean in and peer at some of the data more closely, catching glimpses of labels like "Online Job Postings / Daily Jobless Claims," and "Carbon Dioxide Concentration Tracker."

"Having all this data at my fingertips is slowly driving me mad," he admits, "but I think I'd have a nervous breakdown if I couldn't at least keep a finger on these things. These charts used to show slow changes. Now? Nothing is slow."

Back in the early-to-mid 20th century, there was this great debate between scientists and world leaders about the problem of population control.

Some folks said we were going to just keep pumping out babies until we all starved to death. People like William Vogt and Paul Ehrlich were basically predicting that a plurality of humans would starve to death before the new millennium.

They were wrong, of course. You've heard of the "demographic transition," right?

You're referring to the fact that rich societies tend to have lower birth rates, right?

Yes. It's tied to a number of factors. Industrialization, which leads to urbanization and more restricted living space. Lowered infant mortality rates. Increased access to birth control.

Experts have argued about the causes for decades, ever since social scientists first started to recognize the trend in the '30s.

By the beginning of this century, some people started ringing the alarm bells about the fact that birth rates were falling beneath replacement levels in developed countries. Hence looser immigration policies to support continued economic growth.

But all that has fallen apart.

The birth rates are skyrocketing again in America. It's too early to say for sure, but some predictions say we'll surpass four-point-zero within the next 10 years.

For context: It was, like, one-point-seven in developed countries, before the collapse.

So what are the consequences of that?

It's hard to say. How many humans can the earth's climate support?

Food supply is only theoretically constrained by access to an energy source, but since replicators can generate their own energy source as well, even that isn't a real limit.

You know, all of our models about atmospheric carbon emissions are completely fucked now. Our country is pumping out far less carbon than we used to, and our animal-based foods industries have collapsed, obviously, so that's a win for the environment. But other countries are on the same path as before.

Industrialization has been an ongoing process for well over 200 years, and it's falling apart in a fraction of that time. Urbanization, too, is on the way out. Fewer and fewer people want to live in cities anymore. Who the fuck is gonna pay premium prices for a small apartment in downtown Manhattan anymore? All those buildings are going to squatters.

And, frankly, all of this should've been predictable. The downsides of city life are no longer an acceptable trade-off when you can have all your basic needs met by a replicator, so long as you've got access to an electricity source.

If industrialization and urbanization were the only things holding back the birth rate, what happens when those centuries-long trends come undone in under a single decade?

Eventually, other countries will get their hands on replicators. Where might the birth rate top out, then?

Ten-point-zero?

A lot of us thought that—because of the magic of global capitalism and the demographic transition—humanity was going to stabilize at around 10 billion souls on planet earth.

Now it's not clear what the real limit is.

One hundred billion?

A trillion?

We might get there faster than you think.