Yes, it really a serious problem for Miners and for the country also, as the electricity which is been used for bitcoin mining by the mining network is really high and this electricity can be used for some other purposes also if the consumption decreases to some extent. The solution for this is that we need to replace this electricity with renewable energy something like either Solar energy or Mechanical energy or we can also develop our processing systems and units by which we can start consuming lesser energy. I have found an article that shows you that Bitcoin mining consumes more electricity a year than Ireland.
https://www.theguardian.com/technology/2017/nov/27/bitcoin-mining-consumes-electricity-irelandI think the use electricity for Bitcoin mining not a big deal for environment since electric can obtain from renewable resource like water, heat, wind. For country can be focused to bigger problem like waste paper / plastic / vehicle polution that can demage badly for environment