How does ethereum’s ‘merge’ make the cryptocurrency greener?

theguardian.com:

Ethereum, the second largest cryptocurrency, has completed a plan to drastically reduce its carbon emissions through a software upgrade known as “the merge”.

Here we explain what has changed and what the implications might be.

It is name given to a major change in the security system that underpins the ethereum blockchain, the second most important piece of infrastructure in the entire cryptocurrency space. Until Thursday, ethereum used a system called “proof of work” to determine the validity of transactions on its blockchain and ensure that everyone in the community had consensus about who owned what cryptocurrency.

But in the background, the community has also been experimenting with another system, called “proof of stake”, running a parallel network using that instead of proof of work. Those two networks are what merged on Thursday: there is now only one network, and everyone on it is relying on proof of stake.

The electricity footprint of ethereum should fall from around 8.5GW to less than 85MW, almost overnight. For comparison, Hornsea Two, the largest offshore wind farm in the world, generates 1.4GW of electricity.

That enormous reduction is because of the fundamental difference between proof of work and proof of stake. In the former, ethereum “miners” competed to burn the most electricity and computing power possible, with the winner awarded a cash prize and the right to validate the previous 10 minutes of transactions. That successfully made the system very expensive to attack, since any malicious miner would have to buy more energy and chips than the entire rest of the network combined – but also made it incredibly wasteful.

Proof of stake, by contrast, awards the right to validate transactions to the users with the