Higher growth does not necessarily mean more materials consumed. For example, if you could invent a gas engine that got 120 miles per gallon, it likely wouldn't take much more physical materials to produce, and it would decrease demand for gas. Likewise if you can increase crop yields, or food produced per acre, the end result will be less farm land necessary to feed the population. Productivity is all about doing more with less.

> For example, if you could invent a gas engine that got 120 miles per gallon, it likely wouldn't take much more physical materials to produce, and it would decrease demand for gas.

This is not true in general. Much higher gas efficiency lowers the amount of gas that existing uses need. (Sending one cruise ship to the Azores takes less gas!) That reduced requirement means reduced demand. But it also raises the value of gas. (One gallon of gas does much more work than it used to!) That increased value means increased demand. Maybe we should start sending more cruise ships to the Azores!

The government could tax it to prevent that.

The thing we see though is that demand grows to fill most of the new supply. And many of he advanced in agriculture have only increased energy intensity.

Not always. There's only so much food people can consume, and richer countries are producing less children than poor ones are, so there's an asymptote to a lot of consumption.

> richer countries are producing less children than poor ones are, so there's an asymptote to a lot of consumption

The theory of evolution guarantees that no asymptote based on this mechanism can persist over time. Populations that voluntarily extinguish themselves are replaced by other populations that don't.

There's growth and there's growth. We're probably starting to bump up against ecological limits to the number of humans we can have on this planet ("carrying capacity"), though we might have yet another agricultural revolution get us past that limit. Until then I do think we're near peak population (and indeed, projections already bear this out, and in many countries so does current data).

But we're probably quite far from hitting limits to economic activity. Even when we hit limits for physical economic activity, as you note, there will be virtual economic activity. So I think as far as economic growth goes, we're probably very far from hitting a maximum.

Most humans wouldn't recognize --nor like-- their lives at carrying capacity.

We're likely closer to K/2 than K. Which is a good thing. But as the slow down to K happens (inevitably) things will get interesting.

I don’t think the internet has had the dematerializing effect that many people thought it would. Consumer spending hasn’t exactly decreased. If anything, the internet has made it easier to purchase material goods and services.

The assumption that there are limits to the growth of the material economy is only true if we think of Earth as a closed system. It doesn’t have to be that way.

In fact, even if material growth stopped in its tracks this very day and never resumed, our current economic activity is more than enough to destroy the biosphere given enough time.

We have to either put growth into reverse (which won’t happen—people won’t give up a modern lifestyle, and they’ll guillotine you if you try to make them) or we have to open up the closed system before it’s too late.