you are asking the wrong question; You should ask yourself if a technology that consumes energy necessarily have a high carbon footprint? Of course it's not.
Your Conclusion is wrong.
The World makes a Limited Supply of Energy , Bitcoin requires an ever growing amount of the limited supply.
Just because they monopolize hydro in one area , does not mean a Coal / Nuclear plant does not need to make up the difference on a electric grid to keep it from collapsing under the strain. * Many Nuclear Plants also run Giant Diesel Generators when they need to decrease the output from the reactor.*
The World has still not found a way to dispose of nuclear waste safely without it taking 100s of years.
Limited Supply means when one source draws excessive amounts, it raises the price for everyone else.
Simple Economics.
Plus Saying the renewals can handle the load is pure nonsense, bitcoin rate of consumption is exceeding renewals growth by multiple amounts.