The most famous foray into this change is proof-of-stake. Proof-of-work relies upon calculations that increase in complexity as the blockchain grows, requiring miners to purchase hardware and electricity as a cost of mining. Proof-of-stake is a more direct form of reinvestment; it ties up a miner’s existing coins as stake against the transaction.
Proof-of-stake is most touted for its much lower energy profile than proof-of-work. Altcoin uses it; Ethereum is switching to it; Bitcoin may or may not ever make that transition.
These choices tend to be values-based. Proof-of-work’s original claim to fame was as a solution to the problem of double spending, where the same coins could be spent twice, destroying the integrity of the currency over proof-of-stake cite the importance of Bitcoin’s long-running stability across years of worldwide usage. Proof-of-stake is newer and less phone number database widespread; it’s impossible to declare it equally reliable yet, though it seems plausible that it might be. If so, the energy reduction would be worthwhile.
Rather than asking in isolation how much carbon emissions decentralized web technologies create, many re-frame to draw a baseline. They ask, how do emissions from cryptocurrencies compare to emissions from traditional banking?
I haven’t come across a truly excellent breakdown of ecological cost for cryptocurrencies versus centralized banking, or even a hint of an attempt to compare emissions per dollar equivalent. However, there does exist some good comparative discussion, both of the costs of the two industries and of the value they provide (here’s an article from NASDAQ, for example.