The underlying factors which make this issue complicated also help to define larger issues which the world must deal with, and quickly! It is challenging to weigh the pros and cons of solutions such as proof of work, when there are downsides buried in the long list of positives, which may negate the positive outcomes in the long run. Clearly the entire rebuilding of the internet in a decentralized fashion will not be done exclusively on Bitcoin's codebase. Proof of stake, proof of computational correctness, stake time, and many hybrid options will be used for the use cases they best fit. Steemit has shown us the way to deliver short term benefits that are just plain superior to the alternatives, while still addressing long term problems of its own codebase, as EOS is built out, and we get a handle on what really works. How much of this energy issue will be solved by selecting different consenys algorithms, and how much by switching miners to run on renewable energy? And is anyone weighing the carbon and ecological footprint of solar versus wind? how about the insane impact of battery technology on the natural world? the key is to go full-stack deep in performing the impact audits. don't just stop at renewables vs. fossil fuel power, lets go all the way down!