A lot has been said about mining and about the electricity consumption of the activities related to bitcoin mining. However, I have thought of the alternatives and how other systems produce not just energy waste, but also plenty of useless work and "human waste".
To have a network that can ensure the completeness of transactions, the global accessibility and all the features that bitcoins, and many alts, have at the moment, would probable produce a huge carbon footprint. Just think of the VISA system or the banking system... the amount of people working on it, the waste of commuting to works, the infrastructure.
Thinking of all that, would you still say Bitcoin is bad for the environment?
At least, bitcoin mining is not bad for the environment. The bad thing is, if we use electricity with non eco-friendly resources, then it will be bad for environment. Although bitcoin mining is consuming much power, it still below the usage of other companies such as mineral mining or oil mining.