I've always touted the line about comparing the energy consumed to the value produced. And while I still think that you must normalize the numbers, I also start to grow concerned that its continued growth seems like it might actually be a problem.

Oh, wow, -- lightbulb -- I didn't notice this until I started to write this post. I was going to ruminate about what PoW could we possibly do instead (presuming we need PoW for a good cryptocoin).

Now I'm thinking that this is the correction that will finally level off speculation?

Bitcoin's value is bounded: it can't be worth much more to humanity than the sum of all global financial services (likely worth much less). But its energy consumption is only bounded by the perception of its future value. Hash rate growth is fueled by speculation in continued growth in the bitcoin exchange rate.

At some point the energy consumption may grow fast enough to damper excitement about future gains. Then again, with each halving the inflation rate slows. So it's calibrated to keep increasing.

I wonder if the next Bitcoin community crisis will be different approaches to difficulty or reward. Those seem much more "untouchable" than block size, so hopefully not.