After 3 more halvings (11 years?) the mining rewards per se will fall from c. $300k per block to less than $40k at current prices. That will transform the economics and lead to a great phasing down of current mining capability. But of itself this does not threaten the sustainability of bitcoin.So in 10 years time, are you saying that bitcoin mining will be utilising much less energy than it is today whilst bitcoin continues to scale as a network?
Agreed. The increased hash rate is in effect to prevent an attack by the mining network itself but yes it makes it much more inaccessible to external agents.Until such time as the network matures, the higher the hashrate, the more secure the network is. If a nation state were to attempt to carry out a 51% attack, it's much harder for them to do so - the higher the hashrate.
I’m referring to the fact that the initial protocol envisaged a difficulty of 1, possibly increasing somewhat with adoption, would suffice but that a difficulty of 21 trillion would have been beyond any possible conception.You mention that the algo difficulty is many times greater than 'originally planned'. Can you cite that text as I'd be interested in reading through it?