  The Ethereum ecosystem was maintained by a distributed global network of
computers that required massive amounts of computational power. Previous work
on estimating the energy use and emissions of the Ethereum network has relied
on top-down economic analysis and rough estimates of hardware efficiency and
emissions factors. In this work we provide a bottom-up analysis that works from
hashrate to an energy usage estimate, and from mining locations to an emissions
factor estimate, and combines these for an overall emissions estimate. We
analyze the entire history of PoW Ethereum, from creation to the merge.
