Bitcoin is not at all bad for environment. Only in terms of energy consumption it might be in the last but the innovation had given high security for the users in terms of earning and investment.
Yes, it was only for the use of the bitcoin in internet. However, for the use of the bitcoin in terms of mining, I think it would be bad for the environment, for mining bitcoin requires considerable electrical energy and it will increasingly grow in line with the more difficult it is to mine the bitcoin. But it will have no effect when there is the best innovation in mining