Despite the bankruptcies, hacks and general foul mood in crypto, one metric is moving in the right direction. As we talked about earlier this year, ethereum — the world’s second-largest crypto network — made a move to reduce the energy used in the “mining” process for authenticating transactions on the blockchain. In September, ethereum switched from the so-called proof of work method, in which a bunch of miners compete to solve an authentication puzzle with giant banks of supercomputers, to a method called proof of stake, in which just one miner validates a transaction. That requires much less electricity. Marketplace’s Meghan McCarty Carino spoke with Alex de Vries, the founder of Digiconomist, a website that tracks cryptocurrency energy use, about just how much less energy the ethereum network is consuming, based on a paper that De Vries recently published.