Ethereum’s biggest-ever upgrade just took effect, in what industry experts are calling a game changer for the entire crypto sector. Thus far, all signs suggest the so-called merge — which is designed to cut the cryptocurrency’s energy consumption by more than 99% — was a success.The very first proof-of-stake block of transactions has finalized with a nearly 100% client participation rate. This was, by far, the best-case scenario.The overhaul to the ethereum network fundamentally alters the way the blockchain secures its network and verifies transactions. Most of these changes are happening under the hood and the hallmark of a successful upgrade is if the end user doesn’t feel a difference in the hours and days ahead.Cryptocurrencies such as ethereum and bitcoin are often criticized for the process of mining to generate new coins. Before the merge, both blockchains had their own vast network of miners all over the planet running highly specialized computers that crunched math equations in order to validate transactions. Proof-of-work uses a lot of energy, and it is one of the industry’s biggest targets for critiques.But with the upgrade, ethereum has migrated to a system known as proof-of-stake, which swaps out miners for validators. Instead of running large banks of computers, validators leverage their existing cache of ether as a means to verify transactions and mint new tokens. This requires far less power than mining and experts say it will make the protocol both more secure and more sustainable.The price of ether jumped following the merge. It is trading at around $1,640, up more than 3% in the last hour.Nine teams and more than 100 developers worked on the merge for years. In the hours ahead, this decentralized network of programmers spread out across the planet will monitor the rollout and, if needed, debug as fast as possible.Danny Ryan, a core developer based in Denver who has been working on the merge for five years, tells CNBC that they will be watching for any irregularities via both automated and manual monitoring systems. If issues come up, the corresponding team will debug and release a patch to users, but Ryan says they are pretty confident going into the merge given all the successful dry runs in the last few months.“There might be some sort of small fire that gets put out very quickly,” said Ryan. “But the network as a whole — because of the redundancy across all this different software — will very likely be stable and fine.”cnbc.com