The real issue to me is not whether there are "limits" in that there are never limits if you're always able to apply more effort, but how to define the limit of how return is worth the effort. I'm working on a more formal treatment, but it's simple to understand that if increasing investment makes resources increasingly unavailable, that itself is a real final limit to the usefulness of growth, and counterproductive. I think the real limit of growth is the inflection point right smack in the middle of the "S" curve, because that's where increasing investment produced decreasing returns.

Thanks for the help in making it better!

...that point may have been a while back (1999?) and has been masked by a little proxy for real effort known as "money" (of which an infinite supply exists...)

Nice article btw. I needed 'both heads' to read it but I think I understood most of it.

Nick.

Nick, I think it was before then. I think the time when the earth started to give steadily increasing resistance to physical investment and decreasing real returns, what 'depletion' really means, is what caused money to turn to financial schemes for continually growing returns. Yes, there is an infinite potential for creating money, but I see the time when physical system investment became less profitable and financial investments took over as long before 1999. The turning point I see turns up in lots of history curves at about the same time, as in this curve from Charlie Hall with my overlay of the "S" curve implied, showing the history of US energy use: