Earlier on Thursday, the Ethereum blockchain – which underpins the world’s second-largest cryptocurrency by market value– changed its consensus mechanism from proof-of-work (PoW) to proof-of-stake (PoS), doing away with the need for energy-intensive computing power. Bitcoin, a PoW network, has been facing mounting criticism over its energy use, which is on par with some small countries. These criticisms were echoed in part in a report on bitcoin mining published by the White House last week.