It's not only about emitting CO2, it's also about wasting the earth's surface to produce electricity, such as damming rivers or plastering it with solar panels,

It's not only about emitting CO2, it's also about wasting the earth's surface to produce electricity, such as damming rivers or plastering it with solar panels, or mining for resources to fabricate the bitcoin-mining hardware (which needs to be replaced every few years). The problem will be increasing as the price of BTC goes up. It's a tragedy of the commons.