Cryptocurrencies like bitcoin are produced — or “mined” — in different ways. The most established form of cryptocurrency comes from “proof of work,” which requires users to solve a mathematical equation to validate transactions. Bitcoin, the best-known form of cryptocurrency, depends on “proof of work” mining. But other forms of cryptocurrency, including potential emerging rivals to bitcoin, are pursuing other methods of validating transactions on the decentralized network, and could prove less energy-intensive. Since these would be subject to the new reporting requirements under the Warner plan, even though the traditional forms of mining would not be, Wyden late Thursday bashed the competing amendment as “government-sanctioned safe harbor for the most climate-damaging form of crypto tech.” Other experts dispute that, however.