One area of confusion about blockchain is the perceived negative environmental impact, but this is a problem specific to bitcoin and some other cryptocurrencies. It is caused by the limitations of the decade-old design of bitcoin and due to Bitcoin’s mining process that requires a “proof of work” to validate transactions. Proof of work is a mathematical algorithm that is essential to validate transactions in the Bitcoin blockchain and consumes huge computational power and energy close to what Denmark consumes annually. Other cryptocurrencies operate differently. Ether, for example, uses the proof-of-stake concept, which is energy efficient, while the cryptocurrency ripple does not require mining.