The only reason why Bitcoin energy usage is so high is because the difficulty is automatically adjusted so that the average time between blocks is approximately

The only reason why Bitcoin energy usage is so high is because the difficulty is automatically adjusted so that the average time between blocks is approximately 10 minutes. Any attempts to improve the energy efficiency, rather than reduce total power consumption, will likely just make Bitcoin mining cheaper and bring more miners online. The only practical thing that would reduce the environmental impact of Bitcoin would be a drop in the price of bitcoin. I keep thinking this thing is on its last legs but it keeps going like a bad dream driven only by speculative frenzy. For the record, I'm not against the concept of a decentralized cryptocurrency but most popular cryptocurrencies are very badly suited to actually being currencies and in the meantime just serve to warm the planet.