> 90% of transaction volume on the Bitcoin blockchain is not tied to economically meaningful activities but is the byproduct of the Bitcoin protocol design as well as the preference of many participants for anonymity.
>In other words, 90% of Bitcoin's carbon footprint is used in a partially successful attempt to compensate for its deficient anonymity.
Miners are mainly rewarded by the new bitcoins that are created in each new block. The energy usage does not come from processing transactions; it is largely independent, it is not uncommon that miners even mine blocks that contain no transactions. If you stop 90% of transactions you will definitely not see the hashrate drop by 90%.
It shocks me that so few people seem to understand this; we keep having articles saying that bitcoin transactions are a waste of energy, and everyone ignoring that the block reward halves every few years until it drops to zero, so it not built with the incentives to use this much energy forever. In fact there is the opposite concern: with widespread usage of systems like Lightning Network and no block reward, there may not be enough incentive for people to mine enough to secure the network.