For years, bitcoin critics have maligned the world’s biggest cryptocurrency for polluting the planet. But new data from Cambridge University shows that the geography of mining has drastically changed over the last six months, and experts tell CNBC this will improve bitcoin’s carbon footprint. China’s big crypto crackdown this spring set off a chain reaction in the mining world. For one, it took half the world’s bitcoin miners offline practically overnight. Fewer people mining has meant less machines running and less power being consumed overall, which slashed bitcoin’s environmental impact. Beijing’s new crypto rules ... (full story)