What are the environmental concerns around Bitcoin?

From blog.hycmlab.com

The recent sharp falls in Bitcoin have happened as Tesla’s CEO Elon Musk highlighted his environmental concern about Bitcoin. So here is what all the fuss is about. Bitcoin mining is very ‘dirty’. The amount of electricity consumed to mine bitcoin is about the same as a medium-sized country taking more electricity than Sweden, Ukraine, & Norway. Here is the FT chart showing that based on research from Cambridge University’s Bitcoin Electricity Consumption Index: The estimate on electric use is an estimate that could be wrong. An upper-end estimate eclipses the 133 terawatt estimate and looks for a figure ... (full story)