I think you are talking past each other. Leaving out transaction fees for a second (which are currently a very small percentage of the miner reward). The block

I think you are talking past each other. Leaving out transaction fees for a second (which are currently a very small percentage of the miner reward). The block reward is programmed to half every 4 years, taken alone this together with a fixed market cap would mean that the mining electricity spend would also half every 4 years. So the energy consumption of bitcoin will grow only so long as its market cap also doubles every 4 years. That's a tall order. Bringing back in transaction fees-- I don't think anyone really knows what they will be, but it will be a long time until the dynamics of that are more important than the dynamics of the block reward halving and the market cap.