Yes. You can.
Let's actually generalize it to anything with an outsized carbon footprint (e.g. commuter flights, car dependent housing development, &c).
We will almost certainly continue doing that stuff but it's incompatible with any vaguely desirable ecological outcome. PoW crypto is special in that it is both highly optional (it's not essential to the lifestyles of 99.999% of people) and has easy substitutes.
I’d like to hear what other economic activities you consider “highly optional” and whether they are more or less deserving of economic resources than Bitcoin.
Crypto mining can't be curbed by carbon taxes in any energy market like normal electrical consumption.
It can be done. We banned CFCs after all.
The taxes on PoW specifically interfacing with the financial system is a weak form of banning it and is definitely something that would work though, but what the gp seems to be arguing strongly against. They are asking why the energy price can't be updated to encompass the negative externalities instead of indirectly taxing it through the PoW's blockchain when it interfaces with the financial system.
Carbon taxes on energy used to mine bitcoin will cut into profitability, leading to some proportion of the least-efficient miners turning off because they are no longer profitable.
How to coordinate a global carbon tax seems like a much bigger problem than cryptocurrency. At 0.5% of global energy use, even if crypto mining was magically eliminated in an instant, 99.5% of the problem would still remain.
Also, feels weird to try to address this problem on the demand side instead of the supply side (which has much more direct influence). Machine Learning training is power intensive and location-insensitive, but it feels odd to worry about 'how to enforce carbon taxes on ML training'. "Which uses of energy are economically profitable" seems tangential to "how much carbon is produced by energy generation".