The energy cost of mining will always be bid up to approximately the net value of the reward. So as the price of Bitcoin goes up, so does the mining effort. If the price drops, the energy expended would drop as well.

It's important to note that the cost of energy its priced to is more or less the global lowest cost of energy. No one mines Bitcoin in Los Angeles during the summer. Bitcoin is a way to convert cheap or excess energy anywhere in the world into money, much of it renewable or energy that would go to waste. And most mining is centralized in a few locations for this reason. So doing a simple energy calculation is dishonest.

> The two essential features of a successful currency are that it is an effective form of exchange and a stable store of value, says Ken Rogoff, a professor of economics at Harvard University in Cambridge, Massachusetts, and a former chief economist at the International Monetary Fund (IMF).

> He says Bitcoin is neither

This made me chuckle. The reason the price of bitcoin (and hence the energy cost of mining) is going up is that people have lost faith in the monetary institutions. In a world where the US money supply can go up 23% in a given year with no end in sight is a world in which you can't trust your savings. We had a global pandemic and stock market is up 30% from pre-covid. This is insane. And people aren't dumb. They're just waiting for the other shoe to drop. In the meantime some find Bitcoin to be an effective hedge.