If you compare the energy consumption of traditional banking systems to Bitcoin, you will realise how very efficient blockchain is.
Energy efficient in what sense?
If you are comparing the cost per transaction or per amount of money transferred, then I don't see how Bitcoin could in any way be considered more efficient.
I hardly think so. Try scaling up Bitcoin to the world's current volume of transactions and you'll find it uses vastly more electricity than traditional banking systems use.
We are working on it, so watch this space. The power consumption will not increase linearly, because of tier 2 & 3 solutions. The key is that blockchain is automated. With traditional centralised trust systems, you need buildings full of people running everything.
Buildings full of people are a joke compared to the massive amounts of power wasted on mining.
You will scale the blockchain by .... not using the blockchain. Okay.
It's these deluded comparisons that make blockchain proponents look silly. The "traditional banking system" provides orders of magnitude more services than a blockchain. They are just not comparable.
Only because you desperately wish for this to be true, not because it is.