Do you believe that unchecked human population growth will ultimately result in a "tragedy of the commons" scenario, given enough time, then? — Outlander

I wouldn't describe future projections of human population growth as being particularly like either "tragedy of the commons" or "heat death of the universe", but since you ask, here's how I think it will probably play out:

For thousands of years, global human population remained static or grew only very slowly, and by the year 1700 there were around 600 million people on the planet. So we know from this past experience that this is a number which the planet can support reasonably comfortably and sustainably over a long period of time.

Since 1700 the human population has increased rapidly and dramatically to its present level of 8.2 billion. We don't know whether this is a number which the planet can support sustainably or long term because it is unprecedented in the history of our species; it's an experiment which has never been tried before. This population increase has been made possible by the unsustainable use of all sorts of natural resources: fossil fuels, topsoils, ocean resources and deep aquifer water to name but four. As those resources gradually run out or become increasingly hard and expensive to extract, then logic suggests that the human population is likely to shrink back to its previously sustainable level of around 600 million.

How long that will take, and what it will look like as it happens, is impossible to predict in detail (going back to my analogy of throwing a crumpled up piece of paper). But as a broad-brush scenario, I think that's the most likely outcome.

it is a complex issue with varied perspectives that has been studied and debated for literally centuries — SophistiCat

The way I look at it, it is simultaneously very complex and very simple. Consider crumpling up a piece of paper and throwing it up in the air. Calculating the precise trajectory of the piece of paper might be beyond the ability of the most advanced computer because there are so many variables involved: how tightly you crumple it up, how hard and in what direction you throw it, the weight of the paper, the roughness of the paper, the air temperature, any sideways draughts which might blow it off course, etc.
But despite all of those complexities, you know one thing for certain; when the piece of paper has finished going up, it will come down.

Could you please share your thoughts on why you believe economic growth might need to stop at some point? — javi2541997

I don't see it so much as a "belief", more a statement of the obvious. All economies have to be based on something, and in any finite system, that something will eventually run out. The Roman economy was based on territorial expansion, conquest and extracting wealth and slaves from the conquered territories. When they ran out of new places to expand to, or the places they might potentially expand to were so far away that their supply lines were over-stretched, the economy stopped growing. (Invade Scotland, anyone? No, I'll pass on that.). The growth of the Sumerian civilisation was based on increasing the food supply by irrigation. When new sources of water ran out, and crop yields declined because of salination of the soil, their economy stopped growing. The growth of the Easter Island civilisation was based on trees. When they cut down all their trees, their civilisation stopped growing. And so on.

Some people say that because the potential amount of knowledge is infinite, therefore a "knowledge economy" can continue to expand indefinitely, but I'm a little doubtful about that. I get sent lots of knowledge every day in the form of emails. I probably get around 50 of them every day, most of which I don't have time to read. Would my life be improved if I got 500, or 5,000 of them a day? I'm not sure that it would.

However, I do not think that perpetual economic growth is illogical. It isn't, actually. We can see many examples that corroborate this. — javi2541997

Surely there can be no example of perpetual economic growth, because by definition, to provide an example of perpetual economic growth, you would need to grow the economy in perpetuity, and then say at the end of perpetuity (whenever that is), "See? I told you so". So the only examples of economic growth which can be provided are for economic growth over a finite and relatively short period.

There are, however, numerous examples of societies which failed to achieve perpetual economic growth. Take, for example, the Roman Empire. It grew from the founding of Rome in 753 BC, reached its peak around 180 AD with the emperor Marcus Aurelius, and declined until the fall of Constantinople in 1453.

However, suppose that instead of starting its decline in 180 AD, the Roman Empire had continued to grow its GDP at around 3% per year (a growth rate which most modern economists would be happy with) until the present day, a period of 1845 years. The total size of the Roman economy would now be 4e+23 times larger than its starting point, or if you want it in more traditional notation, 400000000000000000000000 times larger. So all things considered, it's probably a good thing that the Roman economy began to shrink when it did.