Ethereum, the second largest cryptocurrency, will complete a plan to lower its carbon emissions by more than 99% in the next month, the foundation that controls the platform has confirmed. The project, called “the merge”, will result in ethereum switching the underlying technology it uses for validating crypto transactions to a new process that requires less energy to manage. Once complete, the merge will end the role of “miners” in the ethereum ecosystem, helping to dramatically reduce electricity usage. These users run huge quantities of powerful, purpose-built technology all day, every day, to generate random numbers that affect the security of the overall network. The energy consumption of ethereum mining is currently estimated at about 72 terawatt-hours a year, according to Alex de Vries, a Dutch economist who runs the Digiconomist website. That is comparable with the power consumption of Colombia, with a carbon footprint equivalent to that of Switzerland. The changeover will lead to the platform moving away from a “proof of work” process, which requires cryptocurrency miners to generate random numbers to verify records stored on the blockchain – the technology underpinning digital currencies such as ethereum and the more popular bitcoin. Ethereum will instead use a “proof of stake” process, in which the network will be secured by users who “stake” sums of the cryptocurrency, committing themselves to acting honestly at the risk of losing it. De Vries said the switchover would eliminate the majority of electricity usage. “They could cut off a huge chunk of their power demand. I will be working on quantifying that more accurately but at least 99% (probably even 99.9%) reduction should be achievable. This translates to something like the electricity consumption of a country like Portugal (a quarter of all data centres in the world combined) vanishing overnight.” The proof-of-stake model is currently being used on an experimental “beacon” blockchain, where it has been tested to ensure that the theoretical security it provides is sufficient for the multibillion-dollar economy that sits on top of the ethereum network. Now the experimental blockchain will take over the work of the main network. “Imagine ethereum is a spaceship that isn’t quite ready for an interstellar voyage,” the ethereum foundation said, explaining the merge. “With the beacon chain, the community has built a new engine and a hardened hull. After significant testing, it’s almost time to hot-swap the new engine for the old midflight. This will merge the new, more efficient engine into the existing ship, ready to put in some serious lightyears and take on the universe.” There are still potential problems ahead. The foundation said users needed to watch out for an increase in scam activity because hackers could take advantage of the confusion around the switchover to try to trick users into giving up their passwords, their funds or both. “You should be on high alert for scams trying to take advantage of users during this transition,” the organisation said. “Do not send your ETH anywhere in an attempt to ‘upgrade to ETH2’. There is no ETH2 token, and there is nothing more you need to do for your funds to remain safe.” The final stages of the merge are expected to begin on 6 September, the foundation said, with the old blockchain switched off at some point between 10 and 20 September. Ethereum will not be the first network to use proof of stake, and others including cardano and solana have demonstrated the technology at a smaller scale. But its switchover will leave bitcoin, the largest cryptocurrency, facing renewed criticism for its continued reliance on proof of work. The bitcoin network uses 130TWh of electricity a year, De Vries estimates, a sum that will be increasingly difficult to defend if the ethereum blockchain demonstrates that the same capabilities can be achieved in an environmentally friendly manner.