A correction - bitcoin is not anonymous enough to enable any of the use cases you mentioned. But that misses the points - tools can't be blamed for secondary use cases - do you blame physical dollars for enabling child porn?

As far as our carbon budget, how we choose to create energy and how much energy something uses are unrelated concepts. If people pay a proper price for energy that reflects its scarcity and externalities, then there is no problem. In a world where we use 100% renewable energy sources, would you complain about bitcoin mining? In any case, one could argue that the amount of energy required to secure the bitcoin network is a drop in the bucket compared to the amount of energy that (for example) the USA uses to secure the value of the dollar. If we then factor in the pretty obvious benefits of a decentralized currency, it seems like a great idea if the downsides can be properly addressed.

> tools can't be blamed for secondary use cases

Hold on. Technology (and knowledge in general) is ethically neutral.

The action of researching and developing it in a specific way, time and place in never ethically [and politically] neutral.

Making anonymous trades is a legitimate use case, even if we understand that it would be an attractive option for black markets.

> You're literally killing the planet

This kind of hyperbole suggests you didn’t read the person’s comment very closely.

How is using X joules mining bitcoin worse than using it for anything else? Eg. mining gold?

If the energy grid was 100% sustainable would bitcoin still be “literally killing the planet”? Surely not, so maybe the problem is actually the energy source, not this particular use case.

Indeed it might be still killing the planet, if all the renewable energy we can make at the moment were to be used for Bitcoin and so the other needs must use fossil fuels. At the very least, this argument leads to the conclusion that we ought to stop mining Bitcoin until all energy is renewable, but something tells me its advocates won't be happy with that.

> How is using X joules mining bitcoin worse than using it for anything else? Eg. mining gold?

Or powering an MRI machine to detect cancer in a patient. Is it the same ethically?

> You're literally killing the planet to enable...what? Tax evasion? Selling drugs and child porn?

Wow, gotta be one of the best arguments on HN.