These arguments are not applicable: We are a technological civilization. We use energy. We will use more energy with every new technology. Bitcoin is a new technology and its no different from electric cars. As long as Bitcoin totally uses renewables, it can use as much electricity as it wants. The same goes for any other technology - from electric cars to whatever we invent in the future. We don't want to use less energy as a civilization. We want to use green energy. The desire for using less energy only stems from the fact that the current energy production methods are polluting. If they weren't, there would be no problem in using as much energy as desired.