In September, the Ethereum cryptocurrency network managed to pull off what it had been promising to do for years: switch to a model of mining that is far less emissions-intensive than the standard, a move known as the Merge. Did the switch do anything for the currency’s emissions? Could it be a good solution to the huge climate issues plaguing crypto?

The preliminary answer, according to a peer-reviewed opinion paper published Tuesday in the journal Patterns, is, hesitantly, yes. The total energy demand involved with the Ethereum network, the paper estimates, went down by more than 99% after the Merge, and could represent a reduction in energy demands as big as some medium-size countries—an enormous figure.

A brief refresher, first, on what exactly these terms mean. Traditional crypto mining operates on what’s known as a proof-of-work model: constantly running machines in order to race to solve an equation. In this model, the more computing power a miner has, the better chance they have of solving the equation and earning the reward, which incentivizes mining operations to run as many machines as possible 24/7—and creates an enormous amount of associated carbon emissions. By contrast, proof-of-stake, which Ethereum adopted in September, operates more like a lottery system, meaning miners don’t need all those energy-guzzling machines.

The new paper, authored by Alex de Vries of the cryptocurrency blog…