  Bitcoin mining is regularly pointed out for its massive energy consumption
and associated greenhouse gas emissions, hence contributing significantly to
climate change. However, most studies ignore the environmental impacts of
producing mining equipment, which is problematic given the short lifespan of
such highly specific hardware. In this study, we perform a cradle-to-gate life
cycle assessment (LCA) of dedicated Bitcoin mining equipment, considering their
specific architecture. Our results show that the application-specific
integrated circuit designed for Bitcoin mining is the main contributor to
production-related impacts. This observation applies to most impact categories,
including the global warming potential. In addition, this finding stresses out
the necessity to carefully consider the specificity of the hardware. By
comparing these results with several usage scenarios, we also demonstrate that
the impacts of producing this type of equipment can be significant (up to 80%
of the total life cycle impacts), depending on the sources of electricity
supply for the use phase. Therefore, we highlight the need to consider the
production phase when assessing the environmental impacts of Bitcoin mining
hardware. To test the validity of our results, we use the Sphera LCA and
ecoinvent databases for the background modeling of our system. Surprisingly, it
leads to results with variations of up to 4 orders of magnitude for
toxicity-related indicators, despite using the same foreground modeling. This
database mismatch phenomenon, already identified in previous studies, calls for
better understanding, consideration and discussion of environmental impacts in
the field of electronics, going well beyond climate change indicators.
