With the exponential proliferation of the Bitcoin market, there has been an escalating demand for mining computational capacity. This rise, however, has concurrently driven an unsustainable level of electricity consumption, leading to an increase in carbon dioxide emissions, particularly in China. China was the source of over half the world's mining computational power before a ban on mining activities was implemented. This paper seeks to quantify and project the extent of carbon emissions from Bitcoin mining in China. Utilizing a top-down measurement approach, we have computed the carbon emissions emanating from Bitcoin mining in China from January 2017 to June 2021. Our study indicates that China's Bitcoin mining activities resulted in an emission of 77.84 million tons of carbon dioxide within this period. Additionally, our research reveals that Bitcoin mining's energy consumption is not tied to a single power structure, and the temporal migration of mining pool computational capacity can provoke regional electricity demand shocks in China. Our projections, in the absence of policy restrictions, suggest that China's cumulative carbon dioxide emissions from Bitcoin mining could reach 76.40Mt and 722.18Mt by 2030 and 2060, respectively. Consequently, we recommend that policy regulations governing Bitcoin mining activities be bolstered. Based on these findings, we believe that selecting environmentally friendly technological approaches to keep the carbon emissions generated by the issuance of digital currencies within an appropriate range is of utmost importance for sustainable development.