I want to learn and possibly see an open discussion about how sustainable Bitcoin is in the long run.
There is two parts to this:
I have read something about the processing time to brute force transactions and that this is will continue to grow to a point where transactions will no longer be verified. Is this problem resolved with the new protocols or are this a more fundamental flaw?
Brute force-ing these transactions need more and more GPU-power. As long as most electricity is dirty and fossile-based BTC-mining possibly become a greater contributor to carbon emissions. Am I right?