In 1971, the world’s major economies lost their final tether to gold, entering a fully fiat monetary standard. Under this fiat model, inflation has been structurally higher, financial crises no less ruinous, and real growth no higher than under the gold standard. Today, inflation and monetary instability interfere with the ability of billions of individuals worldwide to store their wealth. Bitcoin offers the world an alternative – a sound monetary system outside the control of governments and central banks. Our report considers the merit of Proof of Work, quantifies Bitcoin’s resource costs, and examines pathways towards mitigating the externalities associated with mining.